A method for controlling a roll gap of a twin roll strip process and a twin roll strip caster device

Abstract

The application provides a roll gap control method of a double-roller thin strip process and a double-roller thin strip casting device. In the preparation process, relative movement between two rollers is controlled, or relative movement between the two rollers and control of the roll system in the form of overall movement are controlled to move on the double-roller thin strip casting machine, so that the roll gap only produces floating which can play a role in stabilizing the process and / or improving the quality of the blank. Compared with the traditional roll gap two-way floating method, the technical solution of the application does not cause two-way fluctuation of the roll body clamping force, and does not produce fluctuation of the thickness of the blank. The shear thinning behavior of the semi-solid material can be inhibited, so that the peak pressure of the molten pool is weakened, which is beneficial to real-time control, can prevent various process stability problems such as liquid leakage of the side sealing plate, damage of the side sealing plate, strip jamming and strip breaking, and can also prevent various blank quality problems such as cracks and wrinkles.

Description

Technical Field

[0001] This invention relates to the field of twin-roll thin strip technology, specifically to a method for controlling the roll gap in twin-roll thin strip technology and a twin-roll thin strip casting machine device. Background Technology

[0002] The twin-roll thin strip process was proposed by the British metallurgist Bessemer around 1850. See references: "On manufacture of continuous sheets of malleable iron and steel direct from fluid metal" (Journal of Metals, 1965); "Numerical Simulation of the Fluid Flow, Heat Transfer, and Solidification during the Twin-Roll Continuous Casting of Steel and Aluminum" (Metallurgical and Materials Transactions B, 2016, pp. 740-748).

[0003] Twin-roll thin strip casting machines are also called twin-roll casting machines, twin-roll continuous casting machines, twin-roll casting and rolling mills, twin-roll thin strip mills, twin-roll casting extrusion mills, etc. The billets produced by twin-roll thin strip casting machines are not necessarily just thin strips. "Thin strip" is just a long-standing customary term in the technical field to which this invention patent application is involved and belongs (hereinafter referred to as "the field"). "Thin strip" includes thin strips, pipes, bars, plates, or other billets with special cross-sectional shapes.

[0004] In the twin-roll thin-strip process, the components constituting the molten pool include two crystallizing rolls arranged opposite and parallel to each other. These "crystallizing rolls" are also called "roll bodies." The two crystallizing rolls are respectively called the first roll body and the second roll body, which can be simply referred to as the "two roll bodies." The axis of rotation of the roll body is simply called the roll shaft. The roll shaft of the first roll body is called the first roll shaft, and the roll shaft of the second roll body is called the second roll shaft. The roll shaft is a virtual straight line, and the "first roll shaft and second roll shaft" can be simply referred to as the "two roll shafts." The surface of the roll body that directly contacts the material in the molten pool is called the roll body working surface, which is simply called the "roll surface." Those skilled in the art can directly and unambiguously identify the "roll surface." The surfaces at both ends of the roll body that are perpendicular to the roll shaft are called "end faces." When using contact side seals, a portion of the "end faces" of the roll body makes periodic or non-periodic direct contact with the contact side seals. A gap exists between the two roll bodies; the minimum distance between the two roll bodies is called the roll gap. The minimum distance between the two rollers is called the roller gap opening; the roller gap opening can be less than 1 mm or more than 10 mm; typically, for thin steel strips, the roller gap opening is in the range of 0.5 to 3 mm; the midpoint of the roller gap is called the Nip point; when the molten pool depth is large, a side sealing device is required to support the formation of the molten pool; typically, the contact-type side sealing device is made of refractory material and needs to be in close contact with the roller end under a certain pressure; cooling water channels can be set inside the roller; during the preparation process, the two rollers rotate in opposite directions, and materials need to be added to the molten pool. The materials are moved out of the molten pool from the roller gap under the driving force of the rollers, becoming a billet with a certain specification; the materials entering the molten pool include liquid metal, which can enter the molten pool through a distribution device; the materials may include solid substances, for example, when using the twin-roll method to prepare multilayer materials using a solid-liquid composite method, solid substances need to be added to the molten pool.

[0005] The molten pool geometry and technical basis of the twin-roll strip mill process are drastically different from those of conventional continuous casting. In the twin-roll strip mill, the geometry of the rolls causes the molten pool to gradually narrow along the direction of roll rotation, forming a wedge shape. The area of ​​the free surface of the molten pool is tens of times, even more than a hundred times, larger than the area of ​​the molten pool outlet. For many years, major economies have invested in research on the twin-roll strip mill process. Although a very few steel companies have achieved commercialization of a very few steel grades, they still face stability issues in the production of steel strips, and the range of steel grades they can produce is very limited. This is because, in the absence of experimental methods, the field firmly believes that the growth pattern of the solidified billet shell within the molten pool is as follows: Figure 1 As shown, the two solidified shells begin at the meniscus and gradually increase in thickness until they are welded together to form the Kiss point.

[0006] like Figure 1The solidified shell development process shown can be found in the reference: "Progress in twin roll casting of magnesium alloys, a review" (Journal of Magnesium and Alloys, 2021, pp. 362-391).

[0007] The instability mechanism and stability control of twin-roll thin strip technology is a century-old problem.

[0008] Chinese patent application number 2021101226378 discloses a method for characterizing the transport behavior within the molten pool during twin-roll casting. The tracer method is based on the laminar-turbulent partitioning phenomenon in the molten pool, which was first discovered by the inventors. See reference: "Physical and computational study of a novel submerged entrynozzle design for twin-roll casting process" (Journal of Iron and Steel Research International, 2021, pp. 1390-1399).

[0009] Based on the discovered "laminar-turbulent partitioning phenomenon," the inventors combined "turbulent diffusion theory" and "solid-liquid diffusion theory" to propose a tracer method. Furthermore, Chinese patent application number 2021112909655 discloses a method for measuring the Kiss angle in a twin-roll casting molten pool. Through experiments, the inventors clarified the advantages and disadvantages of the tracer method. To overcome its shortcomings, the inventors proposed a Kiss angle measurement method based on the principle that "macroscopic segregation is difficult to eliminate through post-processing." Thus, the transport process within a twin-roll thin strip molten pool can finally be studied experimentally, something previously unthinkable.

[0010] The background for proposing the tracer method is that existing technologies lack methods for studying the actual billet shell development process and the molten pool transport behavior environment in which the shell develops; conventional continuous casting methods such as the leakage method and the radioactive element method are not applicable to twin-roll thin strip processes; and mathematical models in numerical simulations are based on numerous unverified assumptions, lacking a reliable assumption system. The technical objective of the tracer method is to directly study the billet shell development process and its environment; and to reveal the process instability mechanism by analyzing the billet shell development process and the molten pool transport behavior environment. The physical principle of the tracer method is turbulent diffusion theory. The application basis of the tracer method is that turbulent partitioning exists in the molten pool; specifically, turbulence exists only within the velocity boundary layer of the roll surface; and the turbulent and laminar regions are relatively stable. The preferred tracer delivery strategy for the tracer method is to utilize the solid-liquid diffusion principle. For example, solid copper to liquid aluminum.

[0011] The Kiss angle measurement method was proposed because: tracer methods cannot capture the Kiss point; tracer methods cannot capture the development process of the billet shell as it passes through the two-phase region at the bottom of the molten pool; and the results obtained by tracer methods still cannot explain the actual process instability phenomena. The technical purpose of the Kiss angle measurement method is to: capture the Kiss point; capture the development process of the billet shell as it passes through the two-phase region at the bottom of the molten pool; and further explore the actual process instability mechanism. The physical principle of the Kiss angle measurement method is: segregation; macroscopic segregation is difficult to eliminate through heat treatment. The application basis of the Kiss angle measurement method is: the roller body is the cooling substrate; a solidification process occurs in the molten pool.

[0012] Despite a century and a half of continuous exploration, prior to the present inventors' proposal of the aforementioned tracing method and Kiss angle measurement method, there was no experimental strategy in the world to directly study the actual transport process in the molten pool.

[0013] The transport behavior within the molten pool described in this patent application includes the transport of momentum, heat, and mass.

[0014] The inventors, through laboratory testing of a twin-roll thin strip casting machine using tracer and kiss angle measurement methods, discovered that the actual development process of the "solidified shell" in the molten pool is as follows: Figure 2 As shown.

[0015] like Figure 2 The "solidified shell" shown is different from the traditional solidified shell; for example... Figure 2 The "solidified shell" shown does not have a clear solid fraction characteristic as traditionally understood.

[0016] Through comparison, the inventors discovered that, as Figure 1 As shown and as Figure 2 The difference in the development patterns of the solidified shell shown is as follows: Figure 1As shown, the two curves converge at the Kiss point; Figure 2 As shown, the two straight lines converge at the Kiss point. Figure 2 The experimental results shown indicate that, Figure 1 The understanding presented is fundamentally flawed, such as... Figure 2 The theoretical schematic diagram of the actual transmission process is shown below. Figure 3 As shown.

[0017] like Figures 1 to 3 The common thread in the molten pool transport behaviors shown is that, under ideal conditions, the transport process in the molten pool of the twin-roll strip mill is considered stable. Unsteady transport behavior within the molten pool is attributed to external factors; in other words, process stability issues and / or billet quality problems are caused by external factors. These external factors refer to known process parameters such as molten pool depth, the geometry of the distribution device, the depth to which the distribution device is immersed in the molten pool, the roll speed, the roll diameter, the roll cooling intensity, superheat, and the roll gap. In summary, the traditional view holds that instability and / or billet quality problems in the twin-roll strip mill are caused by external factors; process instability and / or billet quality problems are due to a lack of proper matching of existing process parameters; and process instability and / or billet quality problems are simply due to the difficulty in matching process parameters—that is, process instability and / or billet quality problems are simply due to the narrow process window of the twin-roll strip mill.

[0018] For a century and a half, the field has firmly believed in certain unproven ideas, including such as Figure 1 The solidified shell development process is shown; in fact, the relevant field is unaware that their belief in the transport behavior occurring in the molten pool is actually one-sided, and the relevant field is also unaware of their belief in... Figure 1 The development process and key influencing factors of the solidified shell shown are incorrect; the relevant field firmly believes in the "basic fact" that changes in the roll gap can affect the solidification process in the molten pool; based on this firmly believed "basic fact", some technicians in the field have proposed a technical solution to adjust the development process of the solidified shell by using the roll gap.

[0019] The implementation method of the "technical solution for adjusting the development process of solidified billet shell by utilizing the roll gap opening" is as follows: A driving device drives at least one of the two rollers to become a moving roller, causing relative motion between the two rollers, resulting in periodic and / or aperiodic changes in the distance between them; during this relative motion, the moving roller reciprocates near its equilibrium position. For example... Figure 4The zero-angle roll gap bidirectional floating method shown is detailed in Chinese patent document application number 2017800317704, which discloses a method for operating a twin-roll thin strip continuous casting machine to reduce vibration. The main technical solution is that relative movement occurs between the two rolls, causing the roll gap opening to change. The main technical effect is to reduce the vibration of the casting machine by sacrificing the uniformity of the billet thickness and promoting bidirectional fluctuation of the casting and rolling force.

[0020] like Figure 4 The symbol “ξ” represents the molten pool depth angle; those skilled in the art can directly and without doubt understand the definition of “molten pool depth angle”.

[0021] The casting and rolling force is also called the roll clamping force.

[0022] Based on the traditional understanding of the "technical solution for adjusting the solidified shell development process using roll gap opening," some technicians in this field believe that unilateral roll vibration can refine grains, and that unilateral roll vibration causes relative motion between the two rolls; during this relative motion, the moving roll reciprocates near its equilibrium position. For example... Figure 5 The single-sided roller shown vibrates in a direction perpendicular to the reference plane. For details, see Chinese patent document with application number 2007101853779, which discloses a vibrating double-roll thin strip casting and rolling mill. Its main technical solution is single-sided roller vibration, which will cause bidirectional fluctuation of roller clamping force and change of billet thickness. Its main technical effect is to refine grains.

[0023] In this patent application, the inventors believe that the relative motion between the two rollers will cause changes in the roll gap. The inventors refer to the changes in the roll gap caused by the relative motion between the two rollers as roll gap floating. In the prior art, roll gap floating refers to bidirectional roll gap floating. That is, during the relative motion between the two rollers, one roller moves back and forth near the equilibrium position. In fact, the extent to which bidirectional roll gap floating can affect the development process of the solidified shell in the molten pool is actually unknown in the field.

[0024] The relative motion between the two rollers causes the Nip point to move. Therefore, in this patent application, the roller gap floating can also be referred to as roller gap movement, roller gap shifting, Nip point floating, Nip point movement, or Nip point shifting, etc.

[0025] Under normal circumstances, due to considerations such as the side sealing plate and / or the quality of the billet edge and / or the uniformity of the billet thickness and / or the uniformity of initial solidification, the component of the floating velocity of the Nip point in the direction of the roller shaft is equal to zero during the relative movement between the two rollers. Furthermore, when it comes to roll gap floating, those skilled in the art can directly and unequivocally determine that the roller shafts of the two rollers are set in parallel, and the two roller shafts always remain parallel during the relative movement of the two rollers to produce roll gap floating.

[0026] After the inventors studied the transport behavior within the molten pool using tracer and Kiss angle measurement methods, the inventors concluded that the growth pattern of the solidified shell within the molten pool is as follows: Figure 2 In the developmental state shown, the inventors proposed, in Chinese patent application number 2022101047141, the following... Figure 6 The inclined roll gap bidirectional floating method shown is proposed in Chinese patent document application number 2022110378783. Figure 7 The method of bidirectional floating of roll gap at a fixed opening is shown.

[0027] In Chinese patent application number 2022101047141, the inventors disclosed a method for improving the stability of a crystallizing roll yielding motion in a twin-roll casting process, such as... Figure 6 As shown, the main technical solution is to control the relative movement between the two rollers, so that the roller gap floats in both directions. This technical solution will cause bidirectional fluctuations in the roller clamping force and changes in the thickness of the billet.

[0028] In Chinese patent application number 2022110378783, the inventors disclosed a method for the angled movement of the crystallizing roll in twin-roll casting and extrusion, such as... Figure 7 As shown, the main technical solution is that one roller rotates bidirectionally around another roller. This technical solution is intended to enhance the uniformity of the blank thickness. However, this technical solution still causes bidirectional fluctuations in the roller clamping force.

[0029] like Figures 4 to 7 The roller gap floating methods shown are all bidirectional floating, and the position of the roller gap changes around the equilibrium position; traditional bidirectional roller gap floating is based on the above "basic facts" and aims to control the solidification process.

[0030] Current industrial practices in the steel industry show that applying traditional methods inevitably leads to the following challenges: the two-phase region of steel grades cannot be too wide or too narrow; furthermore, while a few steel grades can be commercially produced, the production process is highly sensitive to process parameters, requires extremely high manufacturing precision for core equipment, and suffers from diverse process stability and billet quality issues, resulting in high production costs. For a century and a half, due to the lack of systematic experimental methods for studying the actual transport behavior of the molten pool, the molten pool has remained a black box, and the relevant field does not know what actually happens inside it. Therefore, the instability mechanism and stability control of the twin-roll thin strip process have become a century-old problem. Summary of the Invention

[0031] Through systematic research, the inventors have discovered that the "basic facts" upon which traditional bidirectional roll gap floating is based are inappropriate. For a given alloy composition, in traditional bidirectional roll gap floating, only one direction can stabilize the process and / or improve billet quality. However, for a given alloy composition, the other direction of bidirectional roll gap floating deteriorates process stability and has a severely adverse effect on billet quality. In other words, for a given alloy composition, to obtain better process stability and / or higher billet quality: either, with the alloy composition unchanged, pressure needs to be continuously applied to the molten pool; or, with the alloy composition unchanged, pressure needs to be continuously reduced in the molten pool.

[0032] The purpose of this invention is to provide a roll gap control method and a twin-roll thin strip casting machine device for a twin-roll thin strip process. Compared with the traditional bidirectional floating roll gap method, it does not cause bidirectional fluctuations in the roll clamping force, nor does it cause fluctuations in the billet thickness. In addition, since the floating control step (or the roll gap floating process; or the relative movement between the two rolls) changes the placement plane of the roll system, a compensation control step (or the roll system movement process) is needed to correct the impact of roll gap floating on the placement plane of the roll system in a timely manner, so as to avoid roll gap floating directions that are detrimental to process stability and / or billet quality.

[0033] "Placement plane" refers to the plane on which the two rollers are located.

[0034] The "placement plane" can also be called the "roller plane".

[0035] As the inventors continued to conduct in-depth and systematic experimental and theoretical research on the actual transport behavior of twin-roll thin strip molten pool using tracer methods and Kiss angle measurement methods, they discovered that: Figure 3 The melt pool transport behavior shown is one-sided.

[0036] The inventors have discovered through research that the transport behavior in the molten pool is quasi-periodic, such as... Figure 2 and 3The molten pool transport behavior shown is merely one state that is relatively easy to capture by tracer methods and Kiss angle measurement methods during quasi-periodic transport. For a century and a half, the art, including that of the inventors, has assumed that the transport process within the molten pool can proceed stably under ideal conditions. However, those skilled in the art, including the inventors, have made breakthroughs in this regard. Figure 1 The traditional understanding shown is very difficult.

[0037] It should be noted that "quasi-periodic" in "transmission behavior is quasi-periodic" means that the transmission behavior has certain regularity, but at present, it is still difficult to represent this regularity with a periodic function.

[0038] It is important to clarify that "quasi-cycle" and "cycle" are completely different: Although the transmission behavior of "cycle" cannot guarantee the stable progress of the process and / or the quality of the billet in many cases, the transmission behavior of "cycle" is a relatively stable process. The transmission behavior of "cycle" can be substantially optimized by adjusting the existing process parameters to achieve the process stability and / or billet quality required for actual production. In other words, in the traditional understanding, the field firmly believes that the inability to achieve the required process stability and / or billet quality in the twin-roll thin-strip process is due to the lack of a more suitable matching relationship of process parameters. However, the transmission behavior of "quasi-cycle" is an absolutely unstable process. The transmission behavior of "quasi-cycle" cannot achieve the required process stability and / or billet quality by optimizing the existing process parameters. For the transmission behavior of "quasi-cycle", we must start from the causes of "quasi-cycle" and suppress or eliminate the occurrence of "quasi-cycle" transmission behavior from the source.

[0039] Through research, the inventors discovered that the field has not realized that there are irreconcilable contradictions within the molten pool. Simply optimizing the current process parameters is not enough to achieve broader success. This is why, after a century and a half, the commercial production of steel strip using the twin-roll thin strip method remains merely a "dream" in the field.

[0040] Through research, the inventors discovered that long-range shear-thinning interfaces exist in the molten pool; these interfaces converge to form Kiss corners; and these interfaces cause periodic transport-like behavior to occur in the molten pool.

[0041] Through research, the inventors have discovered that the long-range shear-thinning interface undergoes quasi-periodic changes. Therefore, the instability and / or billet quality issues of the twin-roll thin-strip process are actually endogenous, rather than entirely caused by changes in external process parameters. More importantly, the instability and / or billet quality issues of the twin-roll thin-strip process are caused by the high-temperature properties of the material. In other words, the process stability and / or billet quality issues of the twin-roll thin-strip process are actually determined by the physical properties of the material. This may overturn the fundamental understanding of the stability and / or billet quality of the twin-roll thin-strip process in this field over the past century and a half.

[0042] Through research, the inventors have discovered that instability and / or billet quality defects are common problems in the twin-roll thin-film process. The root cause of these common problems is the quasi-periodic evolution phenomenon of the long-range shear-thinning interface. Based on experimental results obtained through Kiss angle measurement technology, the inventors have found that the quasi-periodic evolution of the long-range shear-thinning interface is a unique feature of the molten pool in the twin-roll thin-film process and a key difference between the twin-roll thin-film process and conventional continuous casting processes; in other words, the quasi-periodic evolution of the long-range shear-thinning interface is a key difference between moving crystallizer technology and fixed crystallizer technology.

[0043] Through research, the inventors discovered that because the geometry of the molten pool gradually narrows (or converges) from the meniscus to the Nip point, the semi-solid material at the bottom of the molten pool needs to compete to move out. Furthermore, due to the use of a moving crystallizer technology, the material closer to the moving cooling substrate experiences a more stable driving force during this competitive removal process. Moreover, due to its higher solidity and strength, it holds a dominant (or advantageous) position during this process. The different positions of the material at the bottom of the molten pool during removal inevitably lead to different competition outcomes. This differentiated competition results in velocity differences between the semi-solid materials, leading to the formation of a shear force field. Semi-solid metals are non-Newtonian fluids and exhibit shear-thinning properties; the shear force field causes the formation of long-range shear-thinning interfaces. Once formed, these interfaces hinder the transmission of the roller driving force, further worsening the competitive environment within the molten pool. This deterioration of the transport environment accelerates the development of long-range shear-thinning interfaces.

[0044] It should be noted that "long-range" in "long-range shear-thinning interface" refers to the scale visible to the naked eye; specifically, "long-range" refers to a scale ranging from a few millimeters to tens of millimeters. The counterpart to "long-range shear-thinning interface" is "short-range shear-thinning interface".

[0045] The inventors discovered through research that, as Figure 2 and 3The two straight lines shown are actually two long-range shear-thinning interfaces. These interfaces hinder the transmission of the roller driving force, so the material between the two long-range shear interfaces in the molten pool is not easily renewed.

[0046] It should be noted that, as Figure 1 The curve shown converging at the Kiss point is the solidification front; therefore, as... Figure 1 As shown and as Figure 2 The differences in the development process of the solidified shell shown become clearer: as follows Figure 1 As shown, the solidification front converges into a Kiss point; and as... Figure 2 As shown, the long-range shear-thinning interface converges into the Kiss point.

[0047] like Figure 2 As shown, the region between the roll surface and the adjacent long-range shear-thinning interface is the "solidified shell" (the quotation marks are to distinguish it from other shells). Figure 1 (Distinguish the development process of the solidified shell shown).

[0048] Through research, the inventors have plotted the quasi-periodic transport behavior in the molten pool during the preparation of alloy billets with a relatively wide two-phase region, such as... Figures 8 to 12 As shown. Figure 8 The stage shown cannot exist stably indefinitely. Due to multiple factors, including the heat transfer process, the two-phase region at the bottom of the molten pool widens. Unequal competition occurs among the semi-solid materials at the bottom of the molten pool, leading to the formation of long-range shear-thinning interfaces. These interfaces converge to form kiss points / corners, resulting in... Figure 9 The state shown.

[0049] It should be noted that the tip of the Kiss angle, which is considered the Kiss point in the relevant field, does not actually exist because the two long-range shear-thinning interfaces that converge to form the Kiss line are planar and have different velocity directions. However, even if the Kiss point is just a virtual point, it still has some value.

[0050] like Figure 9 As shown, the long-range shear-thinning interface hinders the transmission of the roller driving force, resulting in the lack of force required for the material in the Kiss corner region formed by the convergence of two long-range shear-thinning interfaces to move out of the molten pool. Therefore, the Kiss corner material is not easily renewed. The difficulty in renewing the Kiss corner material promotes the further development of the long-range shear-thinning interface, forming... Figure 10 The state shown.

[0051] The Kiss angle is formed after the convergence of two long-range shear-thinning interfaces. It has both advantages and disadvantages: that is, the Kiss angle has dual properties. The advantage of the Kiss angle is that it prevents the molten pool pressure from connecting (or connecting) with the unsolidified core of the billet exiting the molten pool. The disadvantage of the Kiss angle is that it promotes the further development of the long-range shear-thinning interface. The sudden collapse of the Kiss angle after excessive development will cause the molten pool pressure to rise sharply.

[0052] like Figure 10 As shown, the long-range shear-thinning interface continues to develop, the low-temperature zone in the molten pool expands, and the temperature in the low-temperature zone continues to decrease. Since the depth of the molten pool is constant, the heat carried by the melt entering the pool is also constant. As the low-temperature zone expands and its temperature decreases, the high-temperature zone correspondingly shrinks and its temperature increases, further widening the temperature difference between the low-temperature and high-temperature zones, leading to an extreme molten pool transport environment. The continued development of the long-range shear-thinning interface exhibits an inhibitory effect on the melt flow range; that is, the solidification process has a limiting effect on the flow area, which is a limitation of hydraulic model experiments. The shear-thinning behavior of semi-solid metals is unstable. The long-range shear-thinning interface is formed by the shear-thinning of semi-solid metals. Due to the continuous decrease in the enthalpy of the semi-solid material at the bottom of the molten pool, without external disturbances, the long-range shear-thinning interface naturally collapses, forming... Figure 11 The state shown.

[0053] like Figure 11 As shown, the long-range shear-thinning interface that converges to form the Kiss point / corner collapses, and the semi-solid materials on both sides of the long-range shear-thinning interface instantly weld together (or, the material in the Kiss corner region welds together with the "solidified shell"). The Kiss point / corner disappears, and the shear zone in the molten pool instantly becomes the rolling zone. The shearing process instantly becomes the rolling process. This phenomenon causes a sudden increase in the molten pool pressure, forming a pressure peak.

[0054] Through research, the inventors have discovered that excessive molten pool pressure peaks caused by the collapse of the Kiss angle after excessive development can easily lead to leakage at the side sealing plate, damage to the side sealing plate, and detachment of the side sealing plate's attachments. Excessive molten pool pressure peaks can also exacerbate wear and / or accidental damage to the roller body, which is a core component of the twin-roll thin strip casting machine and is very expensive.

[0055] Through research, the inventors discovered that excessively high peak pressure in the molten pool can also lead to wavy characteristics on the edges of the billet.

[0056] Through research, the inventors have discovered that long-range shear interface collapse can have three possible consequences: roll rotation stops; intense rolling process, leading to consequences sufficient to interrupt the process; intense rolling process, but without leading to consequences sufficient to interrupt the process.

[0057] Through research, the inventors have discovered that the heat transfer process is the direct cause of the collapse of the long-range shear-thinning interface, the shear-thinning characteristics of semi-solid materials are the fundamental cause, and external disturbances can cause the collapse of the long-range shear-thinning interface to occur earlier.

[0058] like Figure 12 As shown, the low-temperature zone is a region of intense rolling. Material in the rolling zone moves out of the molten pool, the area of ​​the low-temperature zone shrinks, the high-temperature zone moves downwards, the temperature of the flow distribution zone decreases, and the temperature of the low-temperature zone increases. For example... Figure 12 The state shown returns to as follows Figure 8 As shown, due to the high temperature in the high-temperature zone, "bright lines" (or hot areas) may appear that run across the billet. The presence of "bright lines" proves that the cyclical transmission process in the molten pool along the roller axis has a certain degree of synchronicity.

[0059] For a description of the "bright line", please refer to the literature "Strip formation and process stability in twin roll strip casting" (Steel Research International, 2001, pp. 484-489). The appearance of the "bright line" is not conducive to the uniformity of the billet structure because the grains at the "bright line" are significantly coarser than those in the normal area.

[0060] Through research, the inventors discovered that the presence of oblique cracks at the edge of the billet indicates that there is a difference in the time scale of the quasi-periodic transmission process along the roller axis; that is, the quasi-periodic transmission process in the molten pool along the roller axis has a certain degree of synchronicity, but is not strictly synchronous; the difference in the time scale of the quasi-periodic transmission process along the roller axis leads to the occurrence of oblique cracks at the edge of the billet.

[0061] Through research, the inventors discovered that suppressing the transmission process of the quasi-periodic structure can inhibit the occurrence of oblique cracks on the edge of the billet.

[0062] The inventors discovered through research that, as Figures 8 to 10 As shown, the roller clamping force oscillates gently and rises slightly; as Figures 10 to 11 As shown, the roller clamping force suddenly increases, and the twin-roll thin strip casting machine experiences vibrations as described in Chinese patent document application number 2017800317704; Figures 11 to 12 As shown, the roller body clamping force oscillates downwards.

[0063] It should be noted that, based on the transmission process shown in 10 to 11, the cause of the vibration of the twin-roll thin strip casting machine has been found; the vibration of the twin-roll thin strip casting machine is not due to the solidification shell development process, but due to the shear thinning characteristics of the semi-solid material; therefore, the technical solution for avoiding casting machine vibration described in Chinese patent document with application number 2017800317704 is obviously not optimal.

[0064] like Figures 10 to 11 The diagram shows the most critical stage for process stability control when preparing a billet material with a wide two-phase region using a twin-roll thin-strip process.

[0065] like Figure 10 The diagram shows the stage in the molten pool with the most abundant characteristics of the quasi-periodic transport process. The detailed transport process in the molten pool during this stage is as follows: Figure 13 As shown.

[0066] like Figure 13 As shown, the separation point is the boundary between the distribution zone and the transition zone; the separation point is the starting point of the separated flow formed when the fast-flowing material carried by the roller (or the roller surface dragging flow) encounters the two-phase region of the molten pool. The separated flow will disturb the distribution zone; after passing the separation point, no pure liquid phase exists, and the viscosity of the material increases dramatically. Figure 13 As shown, the compensation point is the boundary between the transition zone and the shearing / rolling zone. After the separation point, the tracer inner layer moves with the roll body. Due to resistance, the thickness of the tracer inner layer gradually decreases. When the thickness of the tracer inner layer decreases to its minimum value and begins to stabilize, this point with the minimum tracer inner layer thickness is defined as the compensation point. After the compensation point, the thickness of the tracer inner layer no longer changes. The tracer inner layer is also called the drag flow inner layer.

[0067] like Figure 13 As shown, from the meniscus to the separation point (or, the distribution zone): the roller surface drag flow forms and develops; the drag flow is divided into an outer layer and an inner layer. The outer layer of the drag flow turns back to the distribution zone near the separation point, causing disturbance to the distribution zone. The inner layer of the drag flow passes through the separation point with the roller surface.

[0068] like Figure 13 As shown, from the separation point to the compensation point (or, the transition zone): the speed of the inner layer of the roller-draped flow gradually decreases, and the speed of the material in the inner layer of the roller-draped flow decreases more as it is farther away from the roller surface; the thickness of the inner layer of the roller-draped flow gradually becomes thinner; the two-phase material outside the inner layer of the roller-draped flow is driven by the inner layer of the roller-draped flow.

[0069] like Figure 13 As shown, from the compensation point to the Kiss point (or, the shear zone): the long-range shear-thinned interface hinders the transmission of the roller driving force; the Kiss corner material lacks driving force, is not easy to move out of the molten pool smoothly, and is difficult to renew; the shear zone cannot exist stably and will transform into the rolling zone.

[0070] like Figure 13 As shown, from the Kiss point to the Nip point (or, the rolling zone): the solidification endpoint may occur in this region; rolling deformation occurs; the rolling zone is not a region that necessarily exists all the time. For materials with a narrow two-phase region, since it is more difficult to form a Kiss angle, when the molten pool pressure is connected to the unsolidified core of the billet exiting the molten pool in a localized area, this "localized area" does not have a rolling zone.

[0071] Through research, the inventors discovered that the roller clamping force can reflect the state of the long-range shear-thinning interface to a certain extent. The state of the long-range shear-thinning interface is an important reflection of the molten pool transport behavior. The stability of the roller clamping force is basically equal to the stability of the molten pool transport behavior. Therefore, the stability of the roller clamping force is of vital importance to process stability and / or billet quality. Thus, avoiding external interference that disturbs the roller clamping force is also of great importance for the state monitoring and real-time control of the billet preparation process. From this perspective, one direction of the two-way floating of the roller gap is harmful.

[0072] Through numerical simulation studies, the inventors discovered that the reason why wedge-shaped (or convergent) molten pools exhibit such... Figures 8 to 12 The quasi-periodic transmission process shown is due to the existence of a point C in the molten pool, such as... Figure 14 As shown. Figure 14 As shown, u y Represents the contour lines of the velocity component along the Y-axis (or, the direction of gravity), u y =0, point C is the contour line u y =0 is the point closest to the outlet of the molten pool. For example... Figure 14 The image shows a simulation of the molten pool for a horizontal twin-roll thin strip casting machine with constant diameter. Therefore, point C is the line of symmetry of the molten pool and the contour line u. y =0 intersection point.

[0073] like Figure 14 As shown, point C was discovered by the inventors using the enthalpy-porous method based on the finite volume principle. The simulation region has been simplified. In the twin-roll thin-strip process, as... Figure 14 As shown, there is a point C in the molten pool, where the velocity component along the Y-axis is zero. Point C is a critical point: the material between point C and point Nip can continuously escape from the molten pool; however, the material above point C, outside the velocity boundary layer (or, the roller-drafted flow), is difficult to escape. The material that is difficult to escape from the molten pool exhibits two behaviors, one of which is similar to... Figure 11 The first example shows a dual-circulation flow occurring in the distribution zone, while the second example is a semi-solid substance in a stagnant state, formed by the convergence of two long-range shear-thinning interfaces at the Kiss angle.

[0074] The inventors have discovered through research that, without considering economic factors, the following can be avoided in the molten pool: Figure 14 The fundamental strategy at point C is to reduce the depth of the molten pool, thereby eliminating the unequal competitive steps required for the removal of semi-solid materials from the pool. However, this approach lacks practical basis for materials such as steel. The production of steel strips is a commercial activity where profitability is paramount. To achieve profitability, production volume must be comparable to conventional processes. This requires the molten pool to release sufficient heat per unit time. The reduced cooling efficiency caused by an excessively shallow molten pool is unacceptable to businesses.

[0075] Through further research, the inventors discovered that: Figures 8 to 12 The figure shows the transport behavior characteristics exhibited by alloy billets with a relatively wide two-phase region; as shown... Figures 8 to 12 The molten pool transport behavior shown is based on industrial pure aluminum; however, the inventors have discovered that for preparing alloy billets with extremely narrow two-phase regions, it is difficult for kiss angles to appear in the molten pool, and the quasi-periodic transport behavior in the molten pool is similar to that shown in the figure. Figures 8 to 12 The periodic transmission processes shown are fundamentally different.

[0076] Through research, the inventors have discovered that for the preparation of billets with extremely narrow two-phase regions, the Kiss angle is difficult to form or develop to a scale "sufficient to affect the molten pool transport behavior." Therefore, the transport process in the molten pool is unlikely to exhibit clear quasi-periodic characteristics as it does when preparing billets with wider two-phase regions. However, in traditional research, the field has mistakenly regarded "molten pool transport behavior without quasi-periodic characteristics" as "molten pool transport behavior when preparing billets with wider two-phase regions" and "molten pool transport behavior when preparing billets with extremely narrow two-phase regions." The field has not realized the fundamental difference in molten pool transport behavior between preparing billets with wider two-phase regions and those with narrower two-phase regions.

[0077] Through research, the inventors discovered that when preparing billets with extremely narrow two-phase regions, the formation of the Kiss angle is difficult, and the pressure of the molten pool is easily connected to the unsolidified core of the billet exiting the molten pool, leading to billet quality defects such as "ridges," "snake eggs," and "egg pancakes." When these billet quality defects are severe, they escalate into process stability issues.

[0078] Through research, the inventors have discovered that when preparing billets with a wide two-phase region, poor synchronization of the molten pool-like periodic transport behavior along the roller axis can also lead to billet quality defects such as "ridges," "snake eggs," and "egg pancakes."

[0079] Through research, the inventors have discovered that the Kiss angle has both advantages and disadvantages; that is, the Kiss angle has dual properties.

[0080] Through research, the inventors discovered that when preparing billets with extremely narrow two-phase regions, the semi-solid shear thinning characteristics of the material being cast are difficult to visually represent from the transport behavior of the molten pool. Therefore, the dual properties of the Kiss angle are extremely difficult to detect. This may be the fundamental reason why, for a century and a half, humans have never realized that there is no Kiss point in the molten pool, or in other words, humans have not realized that the Kiss point may just be a rare phenomenon of a very small number of billet components.

[0081] The inventors discovered through research that, as Figure 14 The molten pool transport process simulated by the inventors is close to the "actual transport process when preparing a billet with an extremely narrow two-phase region"; because the mathematical model used by the inventors does not consider the actual evolution of physical property parameters, it is always difficult to form a Kiss angle near point C that dynamically interacts with the transport process in the molten pool. Therefore, the molten pool transport behavior exhibits clear and stable characteristics; this "clear and stable characteristic" is similar to... Figures 8 to 12 The melt pool transport behavior during the preparation of a billet with a wider two-phase region is drastically different.

[0082] Through research, the inventors discovered that due to the dual properties of the Kiss angle, during the bidirectional floating process of the roll gap, reducing the molten pool pressure has a significant negative effect on the preparation of alloy billets with a wide two-phase region. The sudden collapse after excessive development of the long-range shear-thinning interface will cause the molten pool pressure to rise sharply, leading to serious accidents such as tape jamming, tape breakage, leakage from the side sealing plate, and damage to the side sealing plate. However, it has a significant beneficial effect on the preparation of alloy billets with an extremely narrow two-phase region. It promotes the generation and stable existence of the Kiss angle, thereby preventing the molten pool pressure from connecting with the unsolidified core of the billet exiting the molten pool, and thus avoiding billet quality defects such as "ridges," "snake eggs," and "egg pancakes."

[0083] Through research, the inventors discovered that, due to the dual properties of the Kiss angle, providing pressure to the molten pool during the bidirectional floating process of the roll gap has a significant beneficial effect on the preparation of alloy billets with a wider two-phase region. It inhibits the excessive development of the long-range shear-thinning interface, thereby avoiding the sudden collapse of the long-range shear-thinning interface after excessive development, which would lead to excessively high peak pressure in the molten pool. This, in turn, avoids serious accidents such as tape jamming, tape breakage, leakage from the side sealing plate, and damage to the side sealing plate, and also avoids quality defects such as edge waves and wrinkles in the billet. However, for alloys with an extremely narrow two-phase region, actively providing pressure to the molten pool makes it more difficult to maintain the stability of the Kiss angle. It may cause the pressure in the molten pool to connect with the unsolidified core of the billet exiting the molten pool, resulting in billet quality defects such as "ridges," "snake eggs," and "egg pancakes."

[0084] Through research, the inventors have discovered that for preparing alloy billets with a relatively wide two-phase region, the key technology of the twin-roll strip mill is to avoid excessive development of the Kiss angle, that is, how to continuously provide pressure to the molten pool. However, for preparing alloy billets with an extremely narrow two-phase region, the key technology of the twin-roll strip mill is how to promote the formation and stable existence of the Kiss angle, that is, how to continuously reduce the pressure in the molten pool. For a century and a half, due to the lack of experimental methods to study the actual transport behavior of the molten pool, the molten pool has been like a black box. The field has been unaware of the mechanism of bidirectional roll gap floating, and has also failed to realize that, for a given material composition, one direction of bidirectional roll gap floating can lead to diverse process stability problems and / or billet quality problems.

[0085] Through research, the inventors discovered that because the Kiss angle has dual properties, and most steel materials have one of these dual properties, with only a very few steel materials falling somewhere in between, this finally explains why only a very few steel materials have achieved commercial production.

[0086] Through research, the inventors have discovered that by rationally utilizing the dual properties of the Kiss angle, the range of steel materials that can be produced using twin-roll thin-strip technology can be expanded.

[0087] Through research, the inventors have discovered that by rationally utilizing the dual properties of the Kiss angle, the range of non-ferrous metal materials that can be prepared using twin-roll thin-strip technology can be expanded.

[0088] It is understandable that "continuously providing pressure to the molten pool" does not mean that the molten pool pressure will rise indefinitely; there is a self-balancing mechanism for molten pool pressure. When pressure is provided to the molten pool, the pressure in the molten pool will naturally drop. For preparing alloy billets with a wide two-phase region, it is necessary to prevent the natural drop in molten pool pressure in a timely manner in order to continuously suppress the development of long-range shear-thinning interfaces. Similarly, "continuously reducing molten pool pressure" does not mean that the molten pool pressure will decrease indefinitely.

[0089] Through research, the inventors discovered that during the rotation of the roller, the moving roller surface carries gas into the meniscus. Driven by the roller's rotation, the gas at the meniscus eventually follows the roller surface into the space between the solidified billet and the roller surface, forming a gas film and / or gas pocket. The gas pocket is generated by the high-frequency vibration (with a vibration frequency in the range of tens to hundreds of hertz) of the gas-liquid interface under the action of the roller's rotation. The movement of the roller, which continuously provides pressure to the molten pool, can promote the continuous discharge of gas from the meniscus and enhance the stability of the gas-liquid interface, thereby reducing and / or avoiding the formation of gas films and / or gas pockets, thus significantly improving the surface quality of the billet and improving the cooling efficiency of the roller.

[0090] It should be noted that ordinary technical personnel in this field can directly and without doubt know about the "meniscus".

[0091] The technical solution adopted by this invention to solve the problems of the prior art includes:

[0092] A method for controlling the roll gap in a twin-roll thin strip casting process, wherein a roll system is mounted on a twin-roll thin strip casting machine, the roll system including a first roll and a second roll arranged opposite each other for preparing a billet, the roll shaft of the first roll being called the first roll shaft, and the roll shaft of the second roll being called the second roll shaft; the plane in which the first roll shaft and the second roll shaft are located is called the placement plane of the roll system; the minimum distance between the first roll and the second roll is called the roll gap; the midpoint of the roll gap is called the Nip point; the moving speed of the billet at the Nip point is called the preparation speed; the moving speed of the Nip point caused by the relative movement between the first roll and the second roll is called the floating speed of the Nip point; the first roll and / or the second roll are movably arranged on the twin-roll thin strip casting machine to allow the roll gap to be adjustable;

[0093] The method includes the following steps:

[0094] During the preparation process, the relative movement between the first roller and the second roller is controlled to cause the placement plane to undergo multiple first rotations; during the occurrence of the multiple first rotations, the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero; the multiple first rotations occur continuously or partially continuously.

[0095] Understandably, in actual manufacturing processes, due to the "load generated during the preparation process" and / or the "deliberately designed roll shape," both roll shafts are approximately straight lines. In fact, in the field of study on molten pool transport behavior and / or roll gap floating, the roll shafts are generally considered to be absolutely straight lines, meaning that both rolls are considered ideal rigid bodies of rotation. For example, in a constant-diameter twin-roll thin strip casting machine, the roll body is a cylinder; a cylinder consists of two bottom surfaces and one side surface; the two bottom surfaces of the cylinder are two identical circular surfaces; the side surface of the cylinder is a curved surface; the two end faces of the roll body are the two bottom surfaces of the cylinder, and the roll surface of the roll body is the side surface of the cylinder.

[0096] It should be noted that what a person skilled in the art can directly and without doubt determine is that during the process of relative movement between the two rollers causing the roller gap to float, the two roller shafts are always parallel.

[0097] It should be noted that what a person skilled in the art can directly and unequivocally determine is that "the two rollers are always parallel" includes "the two rollers are always nearly parallel"; where "the two rollers are always nearly parallel" means that, under the current technological conditions, there may be a definite but unavoidable deviation between the "parallelism" achievable and "absolute, idealized parallelism".

[0098] It is understood that in the present invention patent application documents, "parallel" includes "nearly parallel"; that is, "parallel" should be understood as "parallel or nearly parallel", or "basically parallel", or "approximately parallel".

[0099] Understandably, since the two rollers are parallel, the placement plane can be determined using the plane containing the two rollers. Since perfect parallelism is impossible, the placement plane can also be determined using points on the two rollers that are less affected by changes in process parameters. For example, the placement plane can be determined using the four intersection points of the two rollers with the end faces of the two rollers, or any three intersection points. Another example: taking two points on the first roller where the end faces of the rollers intersect with the roller body, and taking the point on the second roller closest to the center of gravity of the second roller body to determine the placement plane. Yet another example: taking any two points on the first roller and any one point on the second roller to determine the placement plane.

[0100] Understandably, a plane perpendicular to one roller axis can be selected, and then the line connecting the intersection of this plane and the two roller axes can be used to represent the placement plane.

[0101] It should be noted that the moving speed of the billet (or strip; or material; or the material to be cast and rolled) at the Nip point is called the preparation speed; the preparation speed is used to measure how fast the billet preparation process is; the direction of the preparation speed is called the preparation direction.

[0102] It should be noted that the normal to the plane on which the object is placed is called the placement normal; there are infinitely many placement normals.

[0103] It is understandable that the preparation speed reflects how fast the billet preparation process is; the magnitude of the preparation speed is only related to the opposing rotation of the two rollers, and is not related to the movement of the roller system or the relative movement between the two rollers; the preparation direction is always along the placement normal and points in the direction in which the billet moves out of the molten pool.

[0104] It is understandable that the floating velocity can be decomposed into "the component velocity in the preparation direction" and "the component velocity in the placement plane".

[0105] It should be noted that the component of the floating velocity in the preparation direction is also known as the effective velocity.

[0106] It is understandable that "floating speed", "effective speed" and "preparation speed" are all vectors.

[0107] Understandably, "vector" is also called "vector".

[0108] It should be noted that, under natural conditions: the plane in which the first and second rollers are placed is also called the reference plane; the preparation speed is also called the reference speed; and the preparation direction is also called the reference direction.

[0109] It should be noted that, under natural conditions, the normal to the reference plane that passes through point Nip is called the reference line.

[0110] It is understandable that "natural state" refers to a state in which the positions of the two rollers relative to the ground do not change from beginning to end during the preparation process; that is, the "roller gap floating process" mentioned in the patent application of this invention has never occurred during the preparation process, nor has the "roller system movement process" mentioned in the patent application of this invention occurred. In fact, it is precisely because the preparation process in the natural state has various process stability problems and / or billet quality problems that the traditional roller gap floating method has been proposed in this field.

[0111] Understandably, during the preparation process under natural conditions, there is no relative movement between the two rollers, nor is there any movement of the roller system. Therefore, the floating speed is zero, the effective speed is zero, and the placement plane does not change.

[0112] Understandably, the reference plane is a unique plane determined by the form of the twin-roll thin strip casting machine. Therefore, for a horizontal constant-diameter twin-roll thin strip casting machine, the reference plane is parallel to or coincides with the horizontal plane; for an inclined twin-roll thin strip casting machine, the reference plane is a plane at a fixed angle to the horizontal plane; for a horizontal constant-diameter twin-roll thin strip casting machine, during the manufacturing process, no matter how complex the roll gap floating process and / or roll system movement process occur, the position of the reference plane and reference line relative to the ground remains unchanged; the same applies to other types of twin-roll thin strip casting machines.

[0113] Understandably, unlike the placement plane, the reference plane is a fixed plane. That is to say, the movement of the roller system will not affect the position of the reference plane. This is because the reference plane is one of the important references for the roll gap floating and / or the roll system movement. The range of the roll gap floating and / or the roll system movement is constrained by the form of the twin-roll thin strip casting machine. The manner of roll gap floating or roll system movement will be explained later.

[0114] It is understandable that in three-dimensional space, the roll gap is actually a surface, with countless Nip points forming a Nip line and countless Kiss points forming a Kiss line. However, in reality, the terms "Nip line" and "Kiss line" are rarely mentioned in this field. For many years, the terms "Nip point" and "Kiss point" have been widely used in this field. Furthermore, when using "Nip point" and / or "Kiss point" to describe the molten pool transport behavior and / or roll gap floating involved in this patent application, it is not necessary to specifically state that it is on a plane perpendicular to the roll axis. In other words, using "Nip point" and "Kiss point" is actually the common practice in this field. In this patent application, to describe the proposed technical solution, according to the common practice in this field, a plane perpendicular to the roll axis is selected, and then the technical features of the proposed technical solution are expressed on this plane. This is the clearest way and the way that a person skilled in the art can directly and without doubt understand.

[0115] It should be noted that those skilled in the art can directly and without doubt understand that "the midpoint of the roll gap is called the Nip point".

[0116] It is understandable that when studying the roll gap floating process, the two rolls are considered as ideal rigid rotating bodies with their roller shafts parallel. The law of floating velocity is the same on any plane perpendicular to the roller shafts. Therefore, the method that a person skilled in the art can directly and unambiguously understand for studying the roll gap floating process is as follows:

[0117] Choose any plane Ω perpendicular to the roller axis i ;

[0118] Nip line and plane Ω i The intersection point is called the Nip point N. i ;

[0119] Study Nip point N i The laws governing motion.

[0120] It is understandable that, from the normal plane of the reference plane, the normal plane passing through the Nip line in its natural state is chosen as the reference plane Π. i Reference plane Π i With plane Ω i The line of intersection is called the reference line π. i .

[0121] It is understandable that, disregarding the influence of the roller system's motion, during the relative motion between the two rollers, the Nip line and Nip point N... i And the plane on which it is placed can move relative to the ground.

[0122] It is understandable that "not considering the effects of roller system movement" can also be expressed as "no roller system movement occurs, or the effects of roller system movement are eliminated".

[0123] It is understandable that "eliminating the influence caused by the movement of the roller system" can also be expressed as: removing; or, eliminating; or, excluding.

[0124] It is understandable that during the relative motion between the two rollers, the reference plane and the plane Ω... i Reference plane Π i Reference line π i Its position relative to the ground is fixed.

[0125] It is understandable that there are countless normals to a reference plane; however, in this patent application, the normal of the reference plane that passes through the Nip point in its natural state is selected as the reference line; that is, the reference line has two characteristics: the reference line is the normal of the reference plane, and the reference line passes through the Nip point in its natural state.

[0126] Understandably, the reference line is the normal to the reference plane passing through the Nip point in its natural state.

[0127] It is understandable that in three-dimensional space, there are countless "Nip points" and countless reference lines, and countless reference lines form a "reference plane".

[0128] It is understandable that whether the "reference line" passes through the Nip point in its natural state does not affect the description of the scope of protection in the patent application document of this invention.

[0129] It should be noted that, as Figure 15 As shown, take any plane perpendicular to the roller axis, and then display a schematic diagram on this plane showing the relationship between the two roller bodies, the two roller axes, the placement plane, the reference plane, the roller gap, the Nip point, the reference line, the speed of the roller surface passing through the roller gap, the preparation speed, the preparation direction, and the reference direction under different states.

[0130] It is understandable that "under different states" in the above text can also be expressed as "in a natural state or in a non-natural state".

[0131] It should be noted that, as Figure 15 As shown, the "foot of the perpendicular" is a symbol used to indicate a perpendicular relationship; the "foot of the perpendicular" is also called the "perpendicular symbol" or "perpendicular foot symbol".

[0132] It should be noted that, as Figure 15The "speed of the roller surface passing through the roller gap" shown is always the same as the "direction of the speed of the roller surface passing through the roller gap" and the "direction of the preparation speed" because the roller body is regarded as an ideal rigid rotating body; that is, the "direction of the speed of the roller surface passing through the roller gap" and the "preparation direction" are always the same.

[0133] It should be noted that, as Figure 15 As shown, in the natural state, the plane where the two rollers are located is called the reference plane, and the direction of the movement speed of the billet at point Nip is called the "reference direction". The "reference direction" is always perpendicular to the reference plane. In the natural state, the placement plane coincides with the reference plane, and the preparation direction is the same as the reference direction. That is to say, the reference plane is a special case of the placement plane, the reference direction is a special case of the preparation direction, and the reference line is a special case of the placement normal.

[0134] It is understandable that "the placement plane coincides with the reference plane" can also be expressed as "the placement plane is located on the reference plane" or "the placement plane is located at the reference plane".

[0135] It should be noted that, "during the multiple occurrences of the first rotation, the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero," where "inner product" is readily and unambiguously known to those skilled in the art.

[0136] It is understandable that in a three-dimensional rectangular coordinate system (X, Y, Z), let vector U = [x1, y1, z1] and vector V = [x2, y2, z2]. Then, the inner product of vectors U and V is: U·V = x1x2 + y1y2 + z1z2.

[0137] It should be noted that the "inner product" is also called the "scalar product" or the "dot product".

[0138] It is understandable that "during the multiple occurrences of the first rotation, the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero" means that during the multiple occurrences of the first rotation, let the preparation speed be vector U and the floating speed be vector V; then, the inner product of vector U and vector V is always positive or always negative.

[0139] It is understandable that "always greater than zero" can also be expressed as "always positive"; and "always less than zero" can also be expressed as "always negative".

[0140] It is understandable that during multiple different first rotations, if the preparation speed is vector U and the floating speed is vector V, then the inner product of vector U and vector V will always be either positive or always negative.

[0141] It is understandable that "during the multiple first rotations, the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero" can also be expressed as "during the multiple first rotations, the direction of the effective speed is always the same as or always opposite to the preparation direction"; or, "during the multiple first rotations, the inner product of the effective speed and the preparation speed is always positive or always negative"; or, "during the multiple first rotations, the inner product of the floating speed and the preparation speed is always positive or always negative".

[0142] It is understandable that, throughout the entire process of each first rotation, the direction of the effective velocity is always the same as or always opposite to the preparation direction; that is, between the start and end of each first rotation, the effective velocity is never equal to zero; and, no roller system movement occurs (or, the influence of roller system movement is eliminated), the placement plane changes, and the change of the placement plane occurs continuously.

[0143] It is understandable that "the total time during each first rotation" does not include the "starting moment" or the "ending moment"; that is, "the total time during each first rotation" does not include the endpoints.

[0144] It is understandable that "between the start time and the end time" does not include the "start time" or the "end time"; that is, "between the start time and the end time" does not include the endpoint.

[0145] It is understandable that "change in the placement plane" means: when there is no movement of the roller system (or, eliminating the influence of roller system movement), and no relative movement between the two rollers has occurred (or, in the natural state), assuming the two roller shafts are located on the placement plane Θ. 1s After only the relative motion between the two rollers has occurred, assume that the two roller shafts are located in the plane Θ. 2s ; plane Θ 1s and plane Θ 2s Non-coincident, plane Θ 1s and plane Θ 2s intersect.

[0146] It is understandable that a person skilled in the art can directly and unequivocally determine that "effective speed (or floating speed) equals zero" includes "effective speed (or floating speed) approaches zero." Here, "effective speed (or floating speed) approaches zero" means that, under current technological conditions, there may be a definite but unavoidable deviation between "effective speed (or floating speed)" and "zero." For example, during the manufacturing process, the deformation and / or vibration of the two rollers under load cannot be completely eliminated; or, during the roller movement, because the transport behavior in the molten pool is not under ideal conditions, this will also lead to an unavoidable deviation between the actual and intended movement of the rollers.

[0147] It is understood that, unless otherwise specified, in this patent application, "equal to zero" includes "approaching zero"; that is, "equal to zero" should be understood as "equal to zero or approaching zero", or "substantially equal to zero", or "approximately equal to zero". For example, "angular velocity equal to zero" should be understood as "angular velocity equal to zero or approaching zero", or "angular velocity substantially equal to zero", or "angular velocity approximately equal to zero".

[0148] It is understandable that at the beginning of the first rotation, the effective velocity is zero; at the end of the first rotation, the effective velocity is zero; there is no moment when the effective velocity is zero between the beginning and end of a first rotation; that is to say, during the occurrence of a first rotation, the effective velocity is never equal to zero.

[0149] It should be noted that a single relative motion between two rollers refers to the period from the moment the relative motion between the two rollers begins until the end of the current relative motion; and at the beginning and end of the current relative motion, the velocity of one roller relative to the other roller is zero, that is, the floating velocity is zero.

[0150] Understandably, once a relative motion begins between the two rollers, it is considered to have ended as long as the relative speed between the two rollers is zero.

[0151] It is understandable that "the relative speed between the two rollers is equal to zero" can be expressed as: with one of the two rollers as the reference, the speed of the other roller is equal to zero.

[0152] It should be noted that the "roll system" is also called the "double roll system"; the relative movement between the two rolls is the internal movement of the roll system, and the internal movement of the roll system will cause the roll gap to float.

[0153] It should be noted that the roller system can move as a whole on a twin-roll thin strip casting machine.

[0154] It is understandable that "roller motion" refers to the movement of two rolls as a "whole" on a twin-roll thin strip casting machine.

[0155] It is understandable that the movement of the roller system includes at least one of the following:

[0156] Translation;

[0157] Rotate.

[0158] It is understandable that the roller system only undergoes translational motion, and the linear velocity at any point on the roller system has the same magnitude and direction.

[0159] Understandably, the roller system only rotates around a virtual axis, which can be any straight line in space parallel to either the first or second roller axis.

[0160] It should be noted that the movement of the roller system does not cause a change in the relative position between the two rollers; that is, the movement of the roller system neither causes nor affects the roll gap.

[0161] It is understandable that the roller system moves on a twin-roll thin strip casting machine, but if there is no relative movement between the two rollers, then the floating speed and the effective speed are both zero.

[0162] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the movement of the roll system and the relative movement between the two roll bodies do not occur simultaneously; between two adjacent movements of the roll system, one or more first rotations occur.

[0163] Through research, the inventors have discovered that controlling the "movement of the roller system" and the "relative movement between the two rollers" to occur at different times (or asynchronously) can simplify the complexity of the equipment, reduce the manufacturing cost of the equipment, and improve the process robustness.

[0164] It is understood that during the preparation process, the Nth and (N+1)th roller system movements occur sequentially, where N is a positive integer; the Nth and (N+1)th roller system movements occur adjacently; during the Nth and (N+1)th roller system movements, there is no relative movement between the two rollers; between the Nth and (N+1)th roller system movements, that is, between the end of the Nth roller system movement and the beginning of the (N+1)th roller system movement, relative movement occurs between the two rollers, causing the placement plane to undergo one or more first rotations; the specific meaning of "one or more first rotations occur between two adjacent roller system movements" will be explained later.

[0165] It is understood that in other embodiments, the first rotation may occur simultaneously with the movement of the roller system.

[0166] It is understood that in other embodiments, the roller system movement may also occur simultaneously with the first rotation.

[0167] It should be noted that the more detailed methods and specific details of the roller system motion and the relative motion between the two rollers will be explained later.

[0168] It should be noted that what a person skilled in the art can directly and unequivocally determine is that during the movement of the roller system, the two rollers move as a "whole" on the twin-roll thin strip casting machine. Components on the twin-roll thin strip casting machine that are directly or indirectly connected to the first and / or second rollers, such as bearing housings, side sealing devices, distribution devices, and drive mechanisms, can be configured to follow the movement of the roller system or not, as needed. It is only necessary to ensure that the relative movement between the two rollers and the movement of the roller system can operate without interference; that is, it is only necessary to ensure that the movement of the roller system and the movement within the roller system can operate without interference.

[0169] As can be understood, as mentioned above, "effective speed" is the component of "floating speed" in the preparation direction; "effective speed" and / or "change in effective speed" can be used to measure the degree to which the roll gap floating process affects the molten pool transport behavior.

[0170] It is understandable that if no roller system movement occurs during the first rotation, then the "floating speed" of the Nip point and the "ground speed of the Nip point" have the same meaning.

[0171] It is understandable that if, at some moment during the first rotation, the roller system moves simultaneously, then the velocity of point Nip relative to the ground (expressed as vector V) will be... T The representation includes two aspects: firstly, the velocity component of the Nip point relative to the ground caused by the movement of the roller system, represented by the vector V.W On the other hand, the velocity component of the Nip point relative to the ground caused by the relative motion between the two rollers is represented by the vector V. F Therefore, the floating speed = V. F =V T -V W .

[0172] It is understood that, based on the above explanation, it is clear that in the present invention patent application document, "floating velocity" (or, vector V) F The change in the state of the Nip point is completely unrelated to the movement of the roller system. This is because: the simple movement of the roller system will cause a change in the position of the Nip point relative to the ground, and the simple floating of the roll gap will also cause a change in the position of the Nip point relative to the ground; however, the simple movement of the roller system and the simple floating of the roll gap have completely different effects on the molten pool transport behavior; if only the movement of the roller system occurs, without the floating of the roll gap, then there is no need to discuss the change in the state of the Nip point; because discussing the change in the state of the Nip point without the floating of the roll gap is meaningless for the purposes of this patent application.

[0173] Understandably, based on the above explanation of "floating speed", it can be clearly stated that "floating speed" must be generated solely by the relative motion between the two rollers; that is, "first rotation" must be generated solely by the relative motion between the two rollers; therefore, "first rotation" is determined by the relative motion between the two rollers.

[0174] It is understandable that "floating speed", "effective speed" and "first rotation" are used to quantitatively analyze the effect of roll gap floating on the molten pool transfer process. Therefore, "floating speed", "effective speed" and "first rotation" must be generated solely by the relative motion between the two rolls.

[0175] It should be noted that even without the above detailed explanation of "floating speed", those skilled in the art can directly and without doubt know that "floating speed" must be generated solely by the relative motion between the two rollers.

[0176] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the absolute value of the displacement of the Nip point corresponding to one first rotation is in the range of 5 to 50 micrometers; or, the absolute value of the displacement of the Nip point corresponding to one first rotation is in the range of 50 to 500 micrometers; or, the absolute value of the displacement of the Nip point corresponding to one first rotation is in the range of 0.5 to 5 millimeters; or, the absolute value of the displacement of the Nip point corresponding to one first rotation is in the range of 5 to 10 millimeters.

[0177] It is understandable that "the displacement of the Nip point corresponding to one first rotation" refers to the displacement of the Nip point caused solely by the relative motion between the two rollers between the start and end times of one "first rotation".

[0178] Understandably, when studying the "floating speed", we can assume the existence of a three-dimensional Cartesian coordinate system (X', Y', Z'), which remains relatively stationary with respect to the roller system. Then: the speed of the Nip point in the coordinate system (X', Y', Z') is the "floating speed"; "the displacement of the Nip point corresponding to one first rotation", where "the displacement of the Nip point" refers to the displacement of the Nip point in the coordinate system (X', Y', Z').

[0179] It is understandable that if there is no relative motion between the two rollers (or the first roller remains stationary relative to the second roller), and the roller system is stationary relative to the ground at times t1 and t2, and if there is a relative motion between the roller system and the ground between times t1 and t2, and the roller system rotates clockwise around the second roller axis by an angle ω1 without stopping, and the roller system's motion changes the position of the placement plane relative to the ground, then: between times t1 and t2 (or, during the process of the relative motion between the roller system and the ground), the floating speed is always equal to zero.

[0180] It is understandable that if no roller system movement occurs, and assuming that at times t'1 and t'2, the two rollers are relatively stationary (or the velocity of one roller relative to the other is zero), and assuming that between times t'1 and t'2, the two rollers undergo a relative movement, with the first roller rotating clockwise around the second roller axis by an angle ω'1 without stopping, the relative movement between the two rollers causes the placement plane to change its position relative to the ground. During the relative movement between the two rollers, the roller gap opening remains constant. Therefore, between times t'1 and t'2 (or during this relative movement between the two rollers), the floating velocity is never equal to zero, and the direction of the preparation velocity changes continuously.

[0181] It should be noted that even without the above detailed explanation of "floating speed", those skilled in the art can directly and without doubt know that "floating speed" must be generated solely by the relative motion between the two rollers.

[0182] Understandably, the "effective velocity" is equal to zero at the start and end of the "first rotation"; however, since the "effective velocity" is only the component of the "floating velocity" in the preparation direction, the "floating velocity" is not necessarily equal to zero at the start and / or end of the "first rotation".

[0183] It is understandable that the "first rotation" is defined by the "effective speed"; however, the "displacement of the Nip point corresponding to the first rotation" is defined by the "start and end times of the first rotation"; that is to say, the start and end times of the "first rotation" and the "displacement of the Nip point corresponding to the first rotation" are the same.

[0184] Understandably, based on the above explanation of "one relative motion between the two rollers," it can be understood that "one relative motion between the placement plane and the ground" caused solely by the relative motion between the two rollers refers to: no roller system motion occurs (or, the influence of roller system motion is eliminated), from the moment the relative motion between the placement plane and the ground begins until the end of this relative motion between the placement plane and the ground; and at the beginning and end of this relative motion between the placement plane and the ground, the angular velocity of the placement plane is zero, the linear velocity of the placement plane is zero, and the placement plane is stationary relative to the ground.

[0185] It is understandable that without roller system movement (or, excluding the effects of roller system movement), the "one relative movement between the placement plane and the ground" caused solely by the relative movement between the two rollers results in a rotation of the placement plane. However, without roller system movement (or, excluding the effects of roller system movement), the "one relative movement between the placement plane and the ground" is not necessarily equal to the "one relative movement between the two rollers." The "one relative movement between the placement plane and the ground" can be only a part of the "one relative movement between the two rollers."

[0186] Understandably, the above explanations of "floating speed," "effective speed," and "first rotation" also apply to the "second rotation" described below.

[0187] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process further includes the steps of: controlling relative movement between the first roll and the second roll to cause the placement plane to undergo one or more second rotations; referring to the floating speed during the first rotation as the first speed, and referring to the floating speed during the second rotation as the second speed; referring to the inner product of the first speed and the preparation speed as the first inner product, and referring to the inner product of the second speed and the preparation speed as the second inner product; the product of the first inner product and the second inner product is less than zero.

[0188] It is understandable that "the product of the first inner product and the second inner product is less than zero". In this context, those skilled in the art can directly and without doubt know that "product" and "inner product" are different; the object of "product" is "quantity", while the object of "inner product" is "vector"; "quantity" only has magnitude, while "vector" has both magnitude and direction; the result of the "product" of two "quantities" is "quantity", and the result of the "inner product" of two "vectors" is "quantity".

[0189] It is understandable that the effective velocity is never zero between the start and end of a second rotation.

[0190] It should be noted that, as Figure 16 The diagram illustrates the "first rotation" using a horizontal, equal-diameter, twin-roll thin strip casting machine as an example; point N1 is located on line segment O. 1-1 On O2, line segment O 1-1 O2 lies on plane Ψ1; point N2 lies on line segment O 1-2 On O2, line segment O 1-2 O2 lies on plane Ψ2; point O 1-3 Points N4 and N3 are both located on line segment O. 1-4 On O2, line segment O 1-4 O2 lies on plane Ψ3; line segment O 1-1 O 1-2 With arc O 1-2 O 1-3 Tangent at point O 1-2 line segment O 1-3 O 1-4 With arc O 1-2 O 1-3 Tangent at point O 1-3 During the relative motion between the two rollers, the first roller moves relative to the ground, the second roller remains stationary relative to the ground, and the roller system remains stationary relative to the ground.

[0191] It is understandable that, such as Figure 16 As shown, assume that during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero; if the first roller shaft starts from point O... 1-1 Starting from point O, along trajectory O 1-1 ~O 1-2 ~O 1-3 ~O 1-4 Uninterrupted motion to point O 1-4 After stopping at point N1; Nip point starts from point N1 and moves continuously along the trajectory N1~N2~N3~N4 until it stops at point N4; the placement plane moves from plane Ψ1 to plane Ψ3, and the placement plane undergoes a first rotation, causing Nip point to shift from N1 to N3. During this first rotation, the direction of the effective velocity is always opposite to the preparation direction; the first roller shaft moves to point O.1-3 At this point, the first rotation stops; the first roller shaft moves along trajectory O 1-3 ~O 1-4 Movement to point O 1-4 During the process, the placement plane remains unchanged, and the effective speed is always zero; that is, the first rotation is generated by the relative motion between the two rollers; during the entire time of the first rotation (from point O...), the first roller shaft... 1-1 The movement reaches point O 1-3 The time taken to move the placement plane from plane Ψ1 to plane Ψ3, or the time it takes for the placement plane to change continuously; at the beginning of the first rotation (when the first roller shaft is at point O)... 1-1 At the moment when the placement plane is at point O, or at the moment when the placement plane is at point Ψ1, the floating speed is zero and the effective speed is zero; at the end of the first rotation (when the first roller shaft is at point O)... 1-3 At the moment when the plane is located at point Ψ3, or at the moment when the plane is placed at point Ψ3, the floating speed is not equal to zero, and the effective speed is equal to zero.

[0192] It is understandable that "N1→N3" represents a vector with a starting point N1 and an ending point N3, with its direction pointing from point N1 to point N3.

[0193] It is understandable that, such as Figure 16 As shown, assume that during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero; if the first roller shaft starts from point O... 1-1 Starting from point O, along trajectory O 1-1 ~O 1-2 ~O 1-3 Uninterrupted motion to point O 1-3 Stop at point O; then, the first roller shaft moves from point O. 1-3 Starting from point O, along trajectory O 1-3 ~O 1-4 Uninterrupted motion to point O 1-4 After the initial rotation, the placement plane undergoes its first rotation, and point Nip shifts from N1 to N3. During this first rotation, the direction of the effective velocity is always opposite to the preparation direction. Throughout the entire first rotation, the placement plane changes position. During the shift from N3 to N4, the placement plane does not change position. Therefore, the placement plane does not undergo its first rotation, nor does it undergo its second rotation.

[0194] It is understandable that if a relative motion occurs between the two rollers, the floating speed will not be zero; and the placement plane will remain unchanged during the relative motion. Therefore, the relative motion between the two rollers will not cause the placement plane to rotate in the first or second way.

[0195] It is understandable that, such as Figure 16 The illustration describes "first rotation" as "during the relative motion between two rollers, the first roller moves relative to the ground while the second roller remains stationary relative to the ground." It is readily and unequivocally clear to a person skilled in the art that, during the relative motion between the two rollers, when both rollers move simultaneously relative to the ground, after eliminating the influence of possible roller system motion caused by the simultaneous movement of the two rollers relative to the ground, the relative motion between the two rollers can be further transformed (or equivalently) into: the first roller moves relative to the ground while the second roller remains stationary relative to the ground; or, the first roller remains stationary relative to the ground while the second roller moves relative to the ground.

[0196] It is understandable that those skilled in the art can directly and unequivocally determine that, for the sake of billet thickness uniformity, the permissible variation in roll gap opening during billet preparation is minimal. In fact, variations in roll gap opening should be avoided as much as possible, because fluctuations in billet thickness can have a severely adverse impact on subsequent processes, even leading to process interruptions. Specifically, even without considering the adverse effects of continuously decreasing or increasing roll gap opening on process stability and / or billet quality, it is impossible to continuously increase or decrease the pressure in the molten pool by continuously decreasing or increasing the roll gap opening. For example, for steel materials with a wide two-phase region, the roll gap opening is typically no more than 3 mm; even if the roll gap opening could be reduced to zero indefinitely, it is impossible to continuously apply pressure to the molten pool using only 3 mm throughout the preparation process to achieve the goal of continuously suppressing the development of long-range shear-thinning interfaces. For example, for steel materials with a narrow two-phase region, when the roll gap exceeds 3 mm, the Kiss angle cannot be formed at all, and the process cannot proceed. Assuming that the roll gap can be continuously increased from zero to 3 mm throughout the preparation process, it is certain that a 3 mm increase cannot be used to continuously reduce the molten pool pressure throughout the entire preparation process. Excluding technical solutions that utilize solid-liquid composite methods to prepare multilayer thin strips, generally speaking, in industrialized technical solutions that directly prepare steel thin strips using liquid metal on a horizontal constant-diameter twin-roll thin strip casting machine, the change in roll gap cannot exceed 100 micrometers, and may not even exceed 50 micrometers.

[0197] Understandably, during the relative motion between the two rollers, the displacement of the Nip point caused by the relative motion between the two rollers when the placement plane remains unchanged is negligible compared to the displacement of the Nip point caused by the relative motion between the two rollers when the roll gap opening is constant. This also demonstrates that the traditional roll gap floating method is fundamentally unworkable.

[0198] Understandably, as mentioned earlier, the beneficial effect of the allowable change in roll gap during the preparation of the billet on the molten pool is extremely small and unsustainable compared to the technical solution proposed in this patent application. Therefore, the effect of the change in roll gap on the molten pool is negligible. Under this premise, those skilled in the art can directly and unequivocally determine that, regardless of the influence of roll gap, as long as the direction of the effective velocity generated by the relative motion between the two rolls is opposite to the preparation direction, it can have a sustainable effect on increasing the molten pool pressure. Conversely, as long as the direction of the effective velocity generated by the relative motion between the two rolls is the same as the preparation direction... This allows for a sustained reduction in molten pool pressure. This is because, during the preparation process, the first rotation can be accumulated at any spatiotemporal scale according to actual needs without introducing negative effects. This is the key difference between the technical solution proposed in this patent application and the traditional roll gap floating technology. In the technical solution proposed in this patent application, the first rotation can be accumulated at any spatiotemporal scale according to actual needs during the preparation process. Therefore, it can continuously increase or decrease the pressure in the molten pool to achieve the technical objective of suppressing long-range shear-thinning interfaces or promoting the formation of Kiss angles, thereby solving a technical problem that has plagued this field for a century and a half.

[0199] It is understandable that the use of the phrase "the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero" to define the proposed technical solution in the patent application document is both reasonable and practically significant.

[0200] Understandably, in the phrase "multiple occurrences of the first rotation are continuous or partially continuous," "continuous" means that between two adjacent first rotations, one or more of the following situations occur:

[0201] There is no relative movement between the two rollers;

[0202] There is relative motion between the two rollers, but the effective speed is zero and the plane of placement does not change (no roller system movement occurs, or the influence caused by roller system movement is eliminated).

[0203] Understandably, a further explanation of "no relative movement between the two rollers" includes the following situations:

[0204] If two first rotations occur consecutively, the end time of the first first rotation is the start time of the second first rotation.

[0205] or,

[0206] Two first rotations occur consecutively. After the first rotation ends, there is a pause for a period of time before the second first rotation begins.

[0207] Understandably, based on the previous explanation of "second rotation," "the multiple first rotations occurring continuously or partially continuously" means that some of the multiple first rotations occur continuously, while a second rotation occurs during the interval between two discontinuous first rotations. For example, "two consecutive first rotations" occur, followed by a "first rotation" after a certain interval; and during this interval, a second rotation occurs.

[0208] It is understandable that during the second rotation, the effective velocity is never zero; if the direction of the effective velocity is always the same as the preparation direction during the first rotation, then the direction of the effective velocity is always opposite to the preparation direction during the second rotation; if the direction of the effective velocity is always opposite to the preparation direction during the first rotation, then the direction of the effective velocity is always the same as the preparation direction during the second rotation.

[0209] It is understood that "the occurrence of the first rotations continuously or partially continuously" can be expressed as: "the occurrence of the first rotations continuously or partially continuously multiple times"; or, "the occurrence of the first rotations continuously or partially continuously multiple times"; or, "at least two occurrences of the first rotations continuously".

[0210] It should be noted that, as Figure 17 The diagram illustrates the continuous occurrence of two first rotations using a horizontal, equal-diameter twin-roll thin strip casting machine as an example; point N is the Nip point in its natural state; plane Ψ0 is the reference plane; point O... 1-2 Points N1 and N2 are located on line segment O. 1-1 On O2, line segment O 1-1 O2 lies on plane Ψ1; point O 1-4 Points N3 and N4 are located on line segment O.1-3 On O2, line segment O 1-3 O2 is located on plane Ψ2; during the relative motion between the two rollers, the first roller moves relative to the ground, while the second roller remains stationary relative to the ground.

[0211] It is understandable that, such as Figure 17 As shown, four consecutive relative movements occur between the two rollers:

[0212] The first relative movement between the two rollers begins at point O1, along line segment O1O. 1-1 Uninterrupted motion to point O 1-1 After stopping, the placement plane moves from plane Ψ0 to plane Ψ1, and the placement plane undergoes its first rotation. Point Nip is displaced from N to N1. During this first rotation, the direction of the effective velocity is always opposite to the preparation direction.

[0213] The second relative motion between the two rollers, the first roller shaft from point O 1-1 Starting from point O, along line segment O 1-1 O 1-2 Uninterrupted motion to point O 1-2 After stopping, the placement plane always coincides with plane Ψ1, the Nip point is displaced N1→N2, and the effective velocity is always equal to zero.

[0214] The third relative motion between the two rollers, the first roller shaft from point O 1-2 Starting from point O, along line segment O 1-2 O 1-3 Uninterrupted motion to point O 1-3 After stopping, the placement plane moves from plane Ψ1 to plane Ψ2, and the placement plane undergoes a second first rotation. Point Nip is displaced from N3 to N4. During this first rotation, the direction of the effective velocity is always opposite to the preparation direction.

[0215] The fourth relative motion between the two rollers occurs when the first roller shaft moves from point O. 1-3 Starting from point O, along line segment O 1-3 O 1-4 Uninterrupted motion to point O 1-4 After stopping, the placement plane always coincides with plane Ψ2, the Nip point is displaced N3→N4, and the effective velocity is always equal to zero.

[0216] The first rotation and the second rotation occur consecutively.

[0217] It is understood that in the present invention patent application, the displacements N1→N2 and N3→N4 are used to adjust the roll gap opening, and their impact on the molten pool is extremely small and not sustainable. Therefore, the impact of the displacements N1→N2 and N3→N4 on the molten pool pressure is negligible.

[0218] The inventors have discovered that the practical significance of displacements N1→N2 and N3→N4 is that, under current technological conditions, maintaining an absolutely constant roll gap during the first rotation may be difficult, even though an absolutely constant roll gap is beneficial to process stability and / or billet quality. To enable the first rotation to accumulate at any spatiotemporal scale as needed to achieve the desired technical objective, when the roll gap deviates from the set value, the relative movement between the two rolls can be controlled without changing the placement plane to appropriately adjust the distance between them. Alternatively, the roll gap can be adjusted simultaneously with the first rotation, depending on the current technological conditions.

[0219] It is understandable that a single relative movement between two rollers can produce both a first rotation and a second rotation. For example, as... Figure 18 As shown, assume that during the first rotation, the inner product of the floating velocity (or, the first velocity) and the preparation velocity is always less than zero, or the first inner product is always less than zero; assume that during the second rotation, the inner product of the floating velocity (or, the second velocity) and the preparation velocity is always greater than zero, or the second inner product is always greater than zero; t during the preparation process... m To t n At any given moment, no roller system movement occurs (or, the influence of roller system movement is eliminated), and only one relative movement occurs between the two rollers; the first roller shaft starts from point O1 and moves along the trajectory O1~O 1-1 ~O 1-2 ~O 1-3 Uninterrupted motion to point O 1-3 The process stops at point N; point Nip starts from point N and moves continuously along the trajectory N~N1~N2~N3 until it stops at point N3; t m To t n At any given moment, the placement plane first moves from plane Ψ0 to plane Ψ2, then from plane Ψ2 to plane Ψ3, undergoing a first rotation, followed by a second rotation. During the first rotation, the direction of the effective velocity is always opposite to the preparation direction, and the first inner product is always less than zero. During the second rotation, the direction of the effective velocity is always the same as the preparation direction, and the second inner product is always greater than zero. The product of the first and second inner products is less than zero. The first rotation is a relative motion between the placement plane and the ground; the second rotation is a relative motion between the placement plane and the ground. That is to say, if... Figure 18 During the process shown, there were two relative movements between the placement plane and the ground.

[0220] It should be noted that a person skilled in the art would know directly and without doubt that "second rotation" refers to a rotation where "second" and "first" are not used to specify the order of generation.

[0221] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, at least three of the first rotations occur consecutively.

[0222] The inventors have discovered that, under normal circumstances, the more times the first rotation occurs consecutively, the more beneficial it is to the stability of the process and / or the quality of the billet.

[0223] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, at least four of the first rotations occur consecutively.

[0224] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, at least five of the first rotations occur continuously.

[0225] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the number of consecutive occurrences of the first rotation is determined according to any one or more of the following process parameters:

[0226] The duration of one preparation process;

[0227] Physical properties of the material used to prepare the blank;

[0228] The opening of the roll gap;

[0229] The clamping force of the roller body;

[0230] The absolute value of the preparation speed.

[0231] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, during the preparation process, the placement plane only undergoes the first rotation, so that the roll gap only floats in a single direction.

[0232] It is understood that "so that the roll gap floats in only one direction" means that during the preparation process, the direction of the effective speed is always the same as the preparation direction; or, during the preparation process, the direction of the effective speed is always opposite to the preparation direction.

[0233] It is understandable that, in other words, "so that the roll gap floats in only one direction", where "single direction" means that the "direction of the floating speed" of the Nip point is within the "same directional range". When the "direction of the floating speed" is within the "same directional range", "during the preparation process, the direction of the effective speed is always the same as the preparation direction; or, during the preparation process, the direction of the effective speed is always opposite to the preparation direction", the float of the roll gap is considered to be "single direction".

[0234] It is understandable that "during the preparation process, the placement plane only undergoes the first rotation" indicates that the roll gap only floats in a single direction throughout the entire preparation process.

[0235] It is understandable that the purpose of "the placement plane only undergoes the first rotation during the preparation process" is to ensure that the effect of the roll gap floating caused by the relative motion between the two rolls on the pressure of the molten pool is the same. However, the intensity of the effect may differ, and the difference may be significant.

[0236] It is understandable that the direction of the floating speed is perpendicular to the preparation direction and does not affect the unidirectionality of the roll gap floating; that is, the placement plane only undergoes the first rotation, wherein the two rolls can undergo relative motion that makes the direction of the floating speed perpendicular to the preparation direction, or the effective speed equal to zero.

[0237] Furthermore, in a roll gap control method for a twin-roll thin strip process, during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero, so as to allow for an active and continuous increase in the molten pool pressure.

[0238] It is understandable that "actively and continuously increasing the pressure of the molten pool" can promote the renewal of the Kiss angle, which is beneficial for preparing a billet with a wider two-phase region.

[0239] It is understandable that, as mentioned above, "during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero." Its beneficial effects also include: by using the moving roller to squeeze the gas "that is carried into the meniscus region of the molten pool by the movement of the roller surface", it can promote the discharge of the gas that enters between the "solidified billet shell" and the "roller surface", thereby significantly reducing the porosity on the billet surface and improving the surface quality of the billet.

[0240] Furthermore, in a roll gap control method for a twin-roll thin strip process, during the first rotation, the inner product of the floating speed and the preparation speed is always greater than zero, so as to allow for active and continuous reduction of the molten pool pressure.

[0241] It is understandable that "actively and continuously reducing the pressure of the molten pool" can suppress the Kiss angle renewal, which is beneficial for preparing a billet with a narrower two-phase region.

[0242] It is understandable that the determination of the favorable roll gap floating direction for the billet preparation process is based on the physical properties of the billet material being prepared. Generally speaking, under normal circumstances, "in a single preparation process (or, when the composition of the billet material remains unchanged), the effective speed is always in the same direction as the preparation process," or "in a single preparation process (or, when the composition of the billet material remains unchanged), the effective speed is always opposite to the preparation direction." As for the "effective speed," it is always used to suppress the shear thinning characteristics of semi-solid metals to promote the effective renewal of semi-solid material at the bottom of the molten pool; or, it is always used to continuously close the two billet shells to prevent the pressure of the molten pool from being transmitted to the unsolidified core of the billet exiting the molten pool.

[0243] It is understandable that the effect of the first rotation on the molten pool is the same in each occurrence of the first rotation.

[0244] It is understandable that, specifically, based on the physical properties of the prepared material, during the roll gap floating process of the technical solution proposed in this patent application, adjustments to the roll gap floating may be necessary due to other possible influences in the molten pool. For example, in the process of preparing a billet with a wide two-phase region, the direction of the effective velocity is opposite to the preparation direction to increase the pressure in the molten pool. However, when the pressure in the molten pool suddenly decreases due to unexpected situations such as large inclusions entering the molten pool, side sealing plate attachments falling off, drastic fluctuations in superheat, or nozzle flow, based on the dual properties of the Kiss angle, the best solution at this time is to reduce the effective velocity to zero, or to make the direction of the effective velocity the same as the preparation direction, thereby mitigating the adverse effects of the unexpected and sudden decrease in pressure in the molten pool on process stability and / or billet quality by suppressing Kiss angle renewal or promoting Kiss angle formation.

[0245] It is understandable that the difference between the above-mentioned technical solution and the traditional bidirectional floating of the roll gap lies in the fact that the second rotation is not a prerequisite for the occurrence of the first rotation. The second rotation only occurs as needed between multiple first rotations, or it may not occur at all. This is fundamentally different from the traditional bidirectional periodic or bidirectional non-periodic floating of the roll gap. Before the publication of this patent application, those skilled in the art were unaware that the floating of the roll gap in one direction in the "traditional bidirectional periodic or bidirectional non-periodic floating of the roll gap" is detrimental to process stability and / or billet quality. In the process of the traditional bidirectional periodic or bidirectional non-periodic floating of the roll gap, the floating of one direction of the roll gap is related to the floating of the other direction of the roll gap. Each direction is indispensable. The relative motion between the two rollers corresponding to each direction must cancel each other out on the change in the placement plane for the process to proceed. However, "the relative motion between the two rollers corresponding to each direction must cancel each other out on the change in the placement plane" does not mean that "the harmful effect of the roll gap floating in one direction on process stability and / or billet quality" can also be canceled out. In other words, the key difference between the technical solution in this patent application and the traditional technical solution is that, in the preparation process, the roll gap floating direction that is detrimental to process stability and / or billet quality is filtered out, and only the roll gap floating direction that is beneficial to process stability and / or billet quality is retained. This makes the roll gap float in only one direction or mainly in one direction.

[0246] It is understandable that the above-mentioned "roll gap only floats in one direction" means that during the first rotation, the direction of the effective speed is favorable to the billet preparation process.

[0247] It is understandable that the relative motion between the two rollers causes the placement plane to rotate in the first direction, thus changing the placement plane. Since a second rotation is not used to counteract the change in the placement plane caused by the relative motion between the two rollers (the specific method of counteracting this will be introduced later), the drawback of "in the process of bidirectional periodic or bidirectional non-periodic floating of the roller gap in traditional technology, one direction of roller gap floating and the other direction of roller gap floating are both indispensable, and the changes in the placement plane caused by the relative motion between the two rollers in each direction must cancel each other out in order for the process to proceed" is avoided. The roller gap only floats in a direction that is beneficial to the preparation process of the billet and is determined by the material properties.

[0248] It is understandable that the relative motion between the two rollers causes the second rotation. However, the change in the placement plane caused by the relative motion between the two rollers during the second rotation is not intended to offset the change in the placement plane caused by the relative motion between the two rollers during the first rotation. This is fundamentally different from the conventional technique of "bidirectional floating of the roller gap, where the change in the placement plane caused by the relative motion between the two rollers in one direction offsets the change in the placement plane caused by the relative motion between the two rollers in the other direction." Prior to the inventor, it was not known in the art that for most materials, during the bidirectional floating of the roller gap, one direction is beneficial while the other is detrimental.

[0249] Preferably, in a method for controlling the roll gap in a twin-roll thin strip process, the roll gap opening remains constant throughout the entire duration of multiple first rotations.

[0250] Preferably, in a method for controlling the roll gap in a twin-roll thin strip process, the opening of the roll gap is always varied throughout the entire time during multiple occurrences of the first rotation.

[0251] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the roll gap opening remains constant for part or all of the time during a single first rotation.

[0252] It is understandable that the roll gap opening remains constant, meaning the minimum distance between the two rolls does not change. In other words, the roll gap fluctuates at a constant opening to prevent the thickness of the billet from fluctuating.

[0253] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, relative movement occurs between the first roll and the second roll between two consecutive first rotations; however, the inner product of the floating speed and the preparation speed is always equal to zero, and the placement plane remains unchanged.

[0254] It is understandable that "the inner product of the floating speed and the preparation speed is always equal to zero, and the placement plane does not change". Here, "the placement plane does not change" means that there is no movement of the roller system, or, excluding the influence of the movement of the roller system, the placement plane does not change when the inner product of the floating speed and the preparation speed is always equal to zero.

[0255] It is understandable that "the inner product of the floating speed and the preparation speed is always equal to zero, and the placement plane does not change" can also be expressed as: "the inner product of the floating speed and the preparation speed is always equal to zero, and the relative movement between the two rollers does not change the placement plane."

[0256] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the plane containing the first and second roll shafts in its natural state is referred to as the reference plane; the relative motion between the two rolls that generate the first rotation includes one or more of the following motion modes:

[0257] The first roller rotates around the second roller shaft;

[0258] The second roller rotates around the first roller shaft;

[0259] The direction of the velocity of the first roller and / or the direction of the velocity of the second roller are perpendicular to the reference plane;

[0260] The direction of the velocity of the first roller and / or the direction of the velocity of the second roller are oblique to the reference plane;

[0261] The first roller body rotates about any axis parallel to the first roller shaft;

[0262] The second roller rotates about any axis parallel to the second roller shaft.

[0263] It is understandable that any of the above-mentioned "relative motion between the two rollers that generate the first rotation" will cause the Nip point to float and change the placement plane. Different "motion modes" will lead to differences in the trend or rate of change of the effective speed. However, without considering the influence of the roller gap opening, as long as the direction of the effective speed is opposite to the preparation direction, the molten pool pressure can be continuously increased. Conversely, as long as the direction of the effective speed is the same as the preparation direction, the molten pool pressure can be continuously reduced.

[0264] It is understandable that those skilled in the art can directly and without doubt determine that, based on the needs of the actual process, to ensure that the roll gap does not change or changes within an allowable range, the aforementioned "motion mode" and appropriate parameters are combined to enable the first rotation to achieve accumulation at any time and space scale, so that the change in molten pool pressure achieves the desired technical effect.

[0265] It is understandable that "suitable parameters" include the angle between the "direction of the floating speed" and the "preparation direction".

[0266] It is understandable that "the first roller rotates around the second roller shaft" means that during the relative motion between the two rollers, the first roller rotates around the second roller shaft (or the second roller itself) in a circular motion with a constant roller gap. Similarly, it also applies to "the second roller rotates around the first roller shaft".

[0267] It is understandable that "the first roller rotates about any axis parallel to the first roller shaft," where "rotation" means that during the relative motion between the two rollers, the first roller makes circular motion about an axis parallel to the first roller shaft, and the roller gap changes. Similarly, this also applies to "the second roller rotates about any axis parallel to the second roller shaft."

[0268] It is understood that in the present invention patent application, during the relative motion between the two rollers, the first roller rotates around the second roller shaft (or, the second roller; or, an axis parallel to the first roller shaft), where "rotation" refers to circular motion.

[0269] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, during the first rotation, the angle between the direction of the floating speed and the preparation direction is greater than 120 degrees.

[0270] It is understandable that "the angle between the direction of the floating velocity and the preparation direction is greater than 120 degrees" can also be expressed as "the angle between the floating velocity vector and the preparation velocity vector is greater than 120 degrees".

[0271] It is understandable that "the angle between the floating velocity vector and the preparation velocity mass is greater than 120 degrees" indicates that the inner product of the floating velocity and the preparation velocity is less than zero.

[0272] Understandably, for a horizontal, constant-diameter twin-roll thin strip casting machine, assuming the molten pool depth is d and the roll radius is r, then, as Figure 4 The molten pool depth angle ξ is shown as arcsin(d / r); the preferred value of the angle used to increase the molten pool pressure can be set to (180-ξ); that is, the direction of the floating speed points towards the molten pool area; when preparing steel strip using a horizontal equal-diameter twin-roll thin strip casting machine, the molten pool depth angle ξ can be set in the range of 30 to 60 degrees.

[0273] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, during one first rotation, the direction of the speed of the first roll changes continuously with time, with the second roll as the reference.

[0274] It is understandable that during a single rotation, if "the direction of the velocity of the first roller changes continuously with time, taking the second roller as the reference point," then the trajectory of the first roller, taking the second roller as the reference point, is a curve. For example, if the second roller is stationary relative to the ground and the first roller rotates around the second roller, then, taking the second roller as the reference point, the trajectory of the first roller is an arc.

[0275] It is understandable that "the second roller is stationary relative to the ground, and the first roller rotates around the second roller. Therefore, with the second roller as the reference, the trajectory of the first roller is an arc" is one case of "with the second roller as the reference, the direction of the velocity of the first roller changes continuously with time." In the case of "with the second roller as the reference, the direction of the velocity of the first roller changes continuously with time," the trajectory of the first roller can also be an elliptical arc, a parabola, a hyperbola, a trigonometric function, other curves that conform to the function law, or any irregular curve, etc.

[0276] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, during one first rotation, with the second roll as a reference, the direction of the speed of the first roll does not change with time.

[0277] It is understandable that during a single rotation, if "the direction of the velocity of the first roller does not change with time, taking the second roller as the reference frame," then the trajectory of the first roller, taking the second roller as the reference frame, is a straight line. For example, if the second roller is stationary relative to the ground, and the direction of the velocity of the first roller is perpendicular to the reference plane, then, taking the second roller as the reference frame, the direction of the velocity of the first roller does not change, and the trajectory of the first roller is a straight line.

[0278] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process includes, during the preparation process, a step of controlling the relative movement between the first roll body and the second roll body so that the change in the roll gap opening is within a preset range.

[0279] Understandably, by introducing a roll gap control step during the preparation process, the variation in roll gap can be minimized, thereby ensuring that the thickness of the blank is as uniform as possible.

[0280] It is understandable that "controlling the relative movement between the first roller and the second roller, without changing the placement plane, so that the change in the opening of the roller gap is within a preset range" can be achieved by "the relative movement between the two rollers, with the second roller as a reference, the direction of the velocity of the first roller is perpendicular to the roller surface of the second roller, or with the first roller as a reference, the direction of the velocity of the second roller is perpendicular to the roller surface of the first roller".

[0281] It should be noted that in this invention patent application, the roller body is considered as an ideal rigid rotating body; the roller surface refers to the surface of the roller body that is in direct contact with the material in the molten pool; therefore, "the direction of the velocity of the first roller body is perpendicular to the roller surface of the second roller body" and "the direction of the velocity of the second roller body is perpendicular to the roller surface of the first roller body" can both be expressed as "the placement plane does not change"; "the direction of the velocity of the first roller body is perpendicular to the roller surface of the second roller body" can be expressed as "the straight line containing the direction of the velocity of the first roller body passes through the second roller shaft"; or "the direction of the velocity of the first roller shaft points directly to the second roller shaft"; similarly, "the direction of the velocity of the second roller body is perpendicular to the roller surface of the first roller body" can be expressed as "the straight line containing the direction of the velocity of the second roller body passes through the first roller shaft"; or "the direction of the velocity of the second roller shaft points directly to the first roller shaft".

[0282] It is understandable that the purpose of "relative movement between the first and second rollers without change in the placement plane" is to adjust the opening of the roller gap to maintain the uniformity of the blank thickness. This is because, during the relative movement between the two rollers, the change in the roller gap opening may exceed the allowable value of the process. Therefore, it is necessary to adjust the roller gap opening in a timely manner.

[0283] It is understandable that during the first rotation, the direction of the motion speed of one roller relative to another includes the direction pointing towards the long-range shear-thinning interface in the molten pool.

[0284] It should be noted that "long-range" in "long-range shear-thinning interface" refers to a range of scale from a few millimeters to tens of millimeters. For horizontal equal-diameter twin-roll thin strip casting machines, when the roll diameter does not exceed 500 millimeters and pure aluminum billets are being prepared, the area in the molten pool that is no more than 100 millimeters away from the Nip point is the area where the long-range shear-thinning interface exists. Therefore, "pointing to the long-range shear-thinning interface in the molten pool" can be expressed as "pointing to the area in the molten pool where the long-range shear-thinning interface exists".

[0285] It should be noted that what a person skilled in the art can easily understand is that "the area in the molten pool that is no more than 100 mm away from the Nip point" is actually "the area in the molten pool that is no more than 100 mm away from the Nip line". Therefore, "the area in the molten pool that is no more than 100 mm away from the Nip point" is part of the cylinder.

[0286] It should be noted that what ordinary people skilled in the art can easily understand is that the area in the molten pool that is 100 millimeters away from the Nip point is part of the surface of the cylinder.

[0287] It is understandable that both the first and second rotations are generated by the relative motion between the two rollers, and the relative motion between the two rollers does not include the rotation of the rollers themselves. For example, during the manufacturing process, the first roller is stationary relative to the ground; where "the first roller is stationary relative to the ground" means that the first roller rotates at a fixed position relative to the ground.

[0288] Understandably, the relative motion between the two rollers that achieve the first rotation can be designed according to the actual process requirements, including the following forms:

[0289] The first roller rotates around the second roller shaft, and then the second roller rotates around the first roller shaft, and this process is repeated in sequence.

[0290] The first roller moves relative to the ground, while the second roller remains stationary relative to the ground. The first roller moves linearly relative to the ground in a direction perpendicular to the reference plane.

[0291] The first roller moves relative to the ground, while the second roller remains stationary relative to the ground. The first roller moves relative to the ground in a direction oblique to the reference plane.

[0292] The first roller and the second roller move relative to the ground simultaneously, but the ground speeds of the first roller and the second roller are not equal.

[0293] It should be noted that the form of relative motion between the two rollers that achieve the first rotation will be illustrated in detail in the following specific embodiments.

[0294] Furthermore, in a roll gap control method for a twin-roll thin strip process, under natural conditions, the plane containing the first roll shaft and the second roll shaft is called the reference plane, and the direction of the moving speed of the blank at the Nip point is called the reference direction; during one first rotation, the direction of the floating speed does not change, and the direction of the floating speed is perpendicular to the reference plane; or, during one first rotation, the direction of the floating speed does not change, and the direction of the floating speed is perpendicular to the reference direction.

[0295] Through research, the inventors discovered that the motion modes of the moving rollers disclosed in Chinese patent documents with application numbers 2017800317704 and 2007101853779 are essentially one-dimensional motion (or low-dimensional motion; or single-degree-of-freedom motion; or simple motion), meaning that the degree of freedom of the moving roller is unique. However, the motion modes of the moving rollers disclosed in Chinese patent documents with application numbers 2022101047141 and 2022110378783 are essentially two-dimensional motion (or high-dimensional motion; or multi-degree-of-freedom motion; or complex motion), meaning that the moving roller has two degrees of freedom, one direction perpendicular to the reference plane and the other direction parallel to the reference plane.

[0296] The inventors have concluded that, for one-dimensional motion, if no roller system motion occurs (or the influence of roller system motion is eliminated), at a certain moment during the manufacturing process, the component of the moving roller's velocity in the direction parallel to the reference plane is zero, or the component of the moving roller's velocity in the direction perpendicular to the reference plane is zero; that is, if at a certain moment the direction of the moving roller's velocity is parallel or perpendicular to the reference plane, then at that moment, the motion of the moving roller is one-dimensional motion; such as Figure 4 and 5 In the traditional roll gap floating method shown, the motion of the moving roll is one-dimensional.

[0297] The inventors have concluded that, for two-dimensional motion, if no roller system motion occurs (or, the influence of roller system motion is eliminated), at a certain moment during the manufacturing process, the velocity component of the moving roller in the direction parallel to the reference plane is not zero, and the velocity component of the moving roller in the direction perpendicular to the reference plane is not zero; that is, if at a certain moment, the direction of motion of the moving roller is oblique to the reference plane, then at that moment, the motion of the moving roller is two-dimensional motion; such as Figure 6 and 7 The motion of the conventional moving rollers shown all include two-dimensional motion.

[0298] The inventors discovered through research that when the moving roller has two degrees of freedom, that is, when the motion behavior of the moving roller has two-dimensional motion characteristics, the mechanical structure and control system for realizing the two-dimensional motion of the moving roller are relatively complex. If the two-dimensional motion of the moving roller is simplified to one-dimensional motion for part or all of the time in the manufacturing process, it is beneficial to reduce the complexity of the mechanical structure and control system, and can significantly enhance the process robustness.

[0299] It is understandable that, such as Figure 19As shown, take any plane Ψ perpendicular to the first roller shaft. When there is no roller gap floating or roller system movement, the intersection of the first roller shaft and plane Ψ is point O1, and the intersection of the second roller shaft and plane Ψ is point O2. The first roller is a moving roller, and its position relative to the ground can change; the second roller is a stationary roller, and its position relative to the ground does not change. Assume that on plane Ψ, there exists... Figure 19 The diagram shows a two-dimensional rectangular coordinate system (X, Y), with the origin at point Nip in its natural state. During the preparation of the billet, no roller movement occurs (or, the influence of roller movement is eliminated). It is assumed that the first roller shaft moves from point O at a certain time interval. 1-1 The movement reaches point O 1-2 Location; if the first roller shaft along line segment O 1-1 O 1-2 For motion to occur, a driving device is needed to drive the first roller to move simultaneously along the X and Y axes, making such two-dimensional motion difficult to achieve; however, if line segment O... 1-1 O 1-2 Decompose it into one or more stepped shapes; that is, decompose a two-dimensional motion into several one-dimensional motions. For example, make the first roller shaft move along trajectory O. 1-1 ~O' 1-2 ~O 1-2 With movement, the roll gap is easier to control, and the thickness of the billet can be adjusted according to actual needs.

[0300] The inventors discovered through research that large-scale short-range shear-thinning interfaces exist in the molten pool, and these short-range shear-thinning interfaces are related to... Figure 2 The formation mechanism of the long-range shear-thinning interface shown is the same, but the scale is different; the short-range shear interface can be clearly distinguished under an optical microscope. If the motion of the moving roller is decomposed into a stepped shape, it is more like... Figures 4 to 7 The traditional method shown can generate high-frequency mechanical vibrations, which may help suppress the formation and development of short-range shear-thinning interfaces.

[0301] It is understandable that, such as Figure 19 As shown, the first roller is driven by the drive device to follow a stepped trajectory at point O. 1-1 and point O 1-2 Intermittent movement; can occur at point O 1-1 and point O 1-2 You can also set a "step" between points, or at point O. 1-1 and point O 1-2 Multiple "steps" are set between the blanks; generally, the more "steps" there are, the more beneficial it is to the uniformity of the blank thickness; it is more conducive to suppressing the formation and development of short-range shear thinning interfaces; it is conducive to refining grains and further improving the quality of the blank.

[0302] It should be noted that, as Figure 19As shown, at a certain moment in the manufacturing process, if the first roller moves from point O in a two-dimensional manner... 1-1 Along line segment O 1-1 O 1-2 Movement to point O 1-2 If the point is at a certain point, then the corresponding Nip point moves from point N along line segment N1N2 to point N2.

[0303] It should be noted that, as Figure 19 As shown, at a certain moment in the manufacturing process, if the first roller moves from point O in a one-dimensional manner... 1-1 Along trajectory O 1-1 ~O' 1-2 ~O 1-2 Movement to point O 1-2 If the point is at point N, then the corresponding Nip point moves from point N along the trajectory N1~N'2~N2 to point N4.

[0304] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, under natural conditions, the direction of the preparation speed is referred to as the reference direction; during two consecutive occurrences of the first rotation, the angle between the direction of the floating speed and the reference direction does not change during the first rotation; during the second rotation, the angle between the direction of the floating speed and the reference direction does not change; the direction of the floating speed in the first rotation and the direction of the floating speed in the second rotation are perpendicular.

[0305] It is understandable that, such as Figure 19 As shown, if two relative movements occur between the two rollers during a certain period of the preparation process, the first relative movement causes the placement plane to rotate for the first time, and the second relative movement causes the placement plane to rotate for the second time. In the first rotation, the relative movement causes the placement plane to move from plane Ψ1 to plane Ψ2; in the second rotation, the relative movement causes the placement plane to move from plane Ψ2 to plane Ψ3. During the first rotation, the angle between the direction of the floating velocity and the reference direction is always 90 degrees; during the second rotation, the angle between the direction of the floating velocity and the reference direction is always 180 degrees; the direction of the floating velocity in the first rotation and the direction of the floating velocity in the second rotation are perpendicular.

[0306] Furthermore, in a roll gap control method for a twin-roll thin strip process, the direction of the floating speed does not change during one of the first rotations.

[0307] It is understandable that "during one of the first rotations, the direction of the floating speed does not change" means that: assuming there is a three-dimensional rectangular coordinate system (X', Y', Z'), the coordinate system (X', Y', Z') always remains relatively stationary with respect to the roller system; during one or more of the first rotations, the direction of the floating speed in the coordinate system (X', Y', Z') is the same.

[0308] Furthermore, in a roll gap control method for a twin-roll thin strip process, during the first rotation, the maximum absolute value of the floating speed is in the range of 0.1 to 9000 micrometers per second.

[0309] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the frequency of the first rotation is in the range of 0.01 to 10 Hz.

[0310] It is understandable that "frequency of occurrence of the first rotation" refers to the number of times the first rotation occurs per unit time.

[0311] This invention also provides a roll gap control method for a twin-roll thin strip process, wherein the entire roll system is movably mounted on a twin-roll thin strip casting machine; the roll system includes a first roll and a second roll arranged opposite each other for preparing a billet, the roller shaft of the first roll is the first roller shaft, and the roller shaft of the second roll is the second roller shaft; the minimum distance between the first roll and the second roll is called the roll gap; the midpoint of the roll gap is called the Nip point; in its natural state, the plane in which the first roller shaft and the second roller shaft are located is called the reference plane, and the direction of the moving speed of the billet at the Nip point is called the reference direction; the plane in which the first roller shaft and the second roller shaft are located is called the placement plane of the roll system; the first roll and / or the second roll are movably mounted on the twin-roll thin strip casting machine to allow the roll gap to be adjustable;

[0312] The method includes:

[0313] The floating control steps are as follows: control the relative movement between the first roller and the second roller to make the roller gap float and the placement plane change;

[0314] The steps of compensation control are as follows: control the roller system to move as a whole on the twin-roll thin strip casting machine, and change the placement plane;

[0315] The changes to the placement plane caused by the floating control step and the changes to the placement plane caused by the compensation control step are partially or completely offset.

[0316] Understandably, during the compensation control process, the movement of the roller system does not result in a change in the relative position between the two rollers.

[0317] It is understandable that the "steps of floating control" and the "steps of compensation control" are not in any particular order.

[0318] It is understandable that the "floating control steps" and the "compensation control steps" can be performed simultaneously.

[0319] It is understood that the "floating control step" and the "compensation control step" may not be performed simultaneously. When the "floating control step" occurs first, as long as the placement plane is changed to a certain extent during the "floating control step," causing the position of at least one of the placement plane, the first roller, and the second roller to change to a trigger position (e.g., a threshold), the "compensation control step" can be initiated. The "change of the placement plane by the compensation control step" partially or completely offsets (or compensates) the "change of the placement plane by the floating control step." Specifically, the compensation control step is initiated when the current position of the first roller and / or the second roller deviates from a reference position in the reference direction by a threshold greater than or equal to the threshold.

[0320] It is understandable that the "floating control step" and the "compensation control step" can be performed at different times. When the "compensation control step" occurs first, the "floating control step" can begin as long as the placement plane is changed to a certain extent during the "compensation control step," causing the position of at least one of the placement plane, the first roller, and the second roller to change to a trigger position (e.g., a threshold). The "change of the placement plane by the floating control step" can partially or completely offset the "change of the placement plane by the compensation control step." Specifically, the floating control step is initiated when the current position of the first roller and / or the second roller deviates from a reference position in the reference direction by a threshold greater than or equal to a reference position.

[0321] It is understandable that the "floating control step" and the "compensation control step" are not performed simultaneously. Furthermore, in a single preparation process, when the "compensation control step" occurs first, the "change of the placement plane by the floating control step" partially or completely offsets the "change of the placement plane by the compensation control step." Alternatively, it can be understood that the "change of the placement plane by the compensation control step" reserves space for the "change of the placement plane by the floating control step."

[0322] It is understandable that the "float control steps" and the "compensation control steps" are not performed simultaneously, and when the "float control steps" occur first, their purpose is to partially or completely offset the "changes to the placement plane caused by the float control steps" through the "changes to the placement plane caused by the compensation control steps".

[0323] It is understandable that during the entire preparation process, a "float-controlled step" may occur only once, or multiple times.

[0324] It is understandable that during the entire preparation process, a "compensation control step" may occur only once, or multiple times.

[0325] Under normal circumstances, a single relative movement between two rollers is defined as a floating control step; however, depending on the actual situation, multiple consecutive relative movements between two rollers can also be defined as a floating control step.

[0326] Under normal circumstances, a single relative motion between the roller system and the ground is defined as a compensation control step. Of course, depending on the actual situation, multiple consecutive relative motions between the roller system and the ground can also be defined as a compensation control step.

[0327] It can be understood that "one relative motion between the roller system and the ground" refers to the period from the moment when the relative motion between the roller system and the ground begins until the end of the relative motion between the roller system and the ground; and at the beginning and end of the relative motion between the roller system and the ground, the speed of the roller system relative to the ground is zero.

[0328] It is understood that "the floating control step changes the placement plane" means: when no roller system movement occurs, or, eliminating the influence caused by roller system movement, and no roller gap floating has occurred (or, in the natural state), assuming the two roller shafts are located on the placement plane Θ. 1g After the roll gap floats, assume the two roll shafts are located on the placement plane Θ. 2g ; plane Θ 1g and plane Θ 2g Non-coincident, plane Θ 1g and plane Θ 2g Intersecting or parallel.

[0329] It is understood that "the step of compensation control changes the placement plane" means: without considering the influence of roller gap floating, when no roller system movement has occurred (or, in the natural state), assuming the two roller shafts are located on the placement plane Θ 1s After the roller system has moved, assume that the two roller shafts are located on the placement plane Θ. 2s ; plane Θ 1s and plane Θ 2s Non-coincident, plane Θ 1s and plane Θ 2s Intersecting or parallel.

[0330] It is understandable that a change in the placement plane caused by a "compensation control step" can partially or completely offset a change in the placement plane caused by a "float control step".

[0331] It is understandable that a single "change in the placement plane by a compensation control step" can partially or completely offset multiple consecutive "changes in the placement plane by floating control steps".

[0332] It is understandable that a single "change in the placement plane caused by a floating control step" can partially or completely offset multiple consecutive "changes in the placement plane caused by compensation control steps".

[0333] It is understandable that multiple consecutive "changes to the placement plane caused by floating control steps" can partially or completely offset multiple consecutive "changes to the placement plane caused by compensation control steps".

[0334] Understandably, in conventional technology, the relative motion between the two rollers may alter the placement plane. After the relative motion between the two rollers alters the placement plane, it is necessary to rely on the relative motion between the two rollers to reset the placement plane, resulting in the reciprocating floating of the Nip point. This has a significant negative impact on process stability and billet quality. However, in this invention patent application, the "change of the placement plane by the roller system motion" and the "change of the placement plane by the relative motion between the two rollers" are mutually canceled out, allowing for as many roller gap floating directions as possible that are beneficial to process stability and / or billet quality. This avoids the adverse effects caused by the requirement for bidirectional roller gap floating in conventional technology, and this adverse effect is a first-time discovery by the inventors based on a groundbreaking breakthrough.

[0335] It is understandable that "this invention was first discovered by the inventor based on a groundbreaking breakthrough." The "groundbreaking breakthrough" refers to the fact that process stability control and / or billet quality control are core concerns in the relevant field. The inventor's discovery is sufficient to overturn the basic understanding of the relevant field over the past century and has the potential to promote breakthrough progress in process stability control and / or billet quality control in the relevant field, and may even have an incalculable impact on the development of human society.

[0336] It should be noted that, for ease of explanation, in this patent application document, the plane between the placement plane and the cross-sectional plane of the first roller is referred to as the first plane, and the plane between the placement plane and the cross-sectional plane of the second roller is referred to as the second plane.

[0337] It is understandable that the placement plane is an infinitely large plane, but the first plane and the second plane are two planes with finite areas. The first plane coincides with the placement plane, and the second plane coincides with the placement plane.

[0338] Understandably, the inventors, in order to further explain, take two planes with limited areas on the placement plane, namely the first plane and the second plane, and use the changes in these two planes to illustrate "complete cancellation" or "partial cancellation".

[0339] It should be noted that "complete cancellation" means that the changes to the placement plane caused by the floating control steps and the changes to the placement plane caused by the compensation control steps are "completely cancelled" in the reference direction; and that the changes to the placement plane caused by the floating control steps and the changes to the placement plane caused by the compensation control steps are "completely cancelled" in the direction perpendicular to the reference direction.

[0340] It should be noted that "partial cancellation" means that the changes to the placement plane caused by the floating control steps and the changes to the placement plane caused by the compensation control steps are "partially cancelled" in the reference direction; or that the changes to the placement plane caused by the floating control steps and the changes to the placement plane caused by the compensation control steps are "partially cancelled" in the direction perpendicular to the reference direction.

[0341] It should be noted that the following example, which shows the occurrence of a "floating control step" and a "compensation control step" in quick succession, will be used to further explain "partial offset" and "full offset".

[0342] First, take a plane Ω1 perpendicular to the roller shaft, and establish a two-dimensional rectangular coordinate system (X, Y) on plane Ω1, as follows: Figure 20 As shown, the origin of the coordinate system is the Nip point in its natural state; the horizontal axis X passes through the Nip point in its natural state and is perpendicular to the reference line, and any direction is chosen as the positive direction of the horizontal axis X; the vertical axis Y coincides with the reference line, and any direction is chosen as the positive direction of the vertical axis Y.

[0343] Second, let the lines of intersection of the first plane and the second plane with plane Ω1 be line segments λ1 and λ2, respectively; both the first plane and the second plane are finite planes with constant area, and both are movable; the lengths of line segments λ1 and λ2 are constant, and both are movable; let any point on line segment λ1 be point P. i Let P be any point on line segment λ2. j .

[0344] Third, at the start of the floating control steps, let point P... i and point P j The coordinates are (x) i y i ) and (x j y j At the end of the floating control step and the start of the compensation control step, let point P...i and point P j The coordinates are (x) i1 y i1 ) and (x j1 y j1 At the end of the compensation control step, let point P... i and point P j The coordinates are (x) i2 y i2 ) and (x j2 y j2 ).

[0345] Fourth, let the floating control steps make point P i and point P j The displacement components in the reference direction are vectors S. i1 and vector S j1 Suppose that the steps of the compensation control make point P i and point P j The displacement components in the reference direction are vectors S. i2 and vector S j2 .

[0346] Fifth, assume that the floating control steps make point P i and point P j The displacements in the direction perpendicular to the reference direction are vectors T. i1 and vector T j1 Suppose that the steps of the compensation control make point P i and point P j The displacements in the direction perpendicular to the reference direction are vectors T. i2 and vector T j2 .

[0347] In the reference direction, "partial cancellation" means:

[0348] There exists at least one point in the first plane that satisfies (y i2 -y i1 ) 2 <(y i1 -y i ) 2 Meanwhile, (y i2 -y i ) 2 <(y i1 -y i ) 2 ;

[0349] or,

[0350] There exists at least one point in the second plane that satisfies (y j2 -y j1 )2 <(y j1 -y j ) 2 Meanwhile, (y j2 -y j ) 2 <(y j1 -y j ) 2 .

[0351] In the reference direction, "complete cancellation" means:

[0352] For any point on the first plane, (y i2 -y i1 ) 2 ≥(y i1 -y i ) 2 Meanwhile, vector S i1 and vector S i2 Vectors with opposite directions or both equal to zero;

[0353] and,

[0354] For any point on the second plane, (y j2 -y j1 ) 2 ≥(y j1 -y j ) 2 Meanwhile, vector S j1 and vector S j2 Vectors with opposite directions or both equal to zero.

[0355] It is understandable that "vector S" i1 and vector S i2 "Vectors with opposite directions or both equal to zero" can be expressed as: "Vector S" i1 Direction and vector S i2 The direction is opposite, or, vector S i1 and vector S i2 "All are equal to zero vectors".

[0356] It is understandable that "vector S" j1 and vector S j2 "Vectors with opposite directions or both equal to zero" can be expressed as: "Vector S" j1 Direction and vector S j2 The direction is opposite, or, vector S j1 and vector S j2 "All are equal to zero vectors".

[0357] It is understood that, for example, in one embodiment, a "floating control step" and a "compensation control step" occur sequentially and adjacently; in the floating control step, the roll gap is constant, and the first roll rotates clockwise around the second roll axis by an angle of a degrees; in the compensation control step, the roll system rotates counterclockwise around the second roll axis by an angle of a degrees; the "change of the placement plane by the floating control step" and the "change of the placement plane by the compensation control step" completely cancel each other out in the reference direction; for a point at the second roll axis, vector S j1 and vector S j2 All are equal to zero vectors; for a point on the first plane, vector S is equal to zero vector. j1 Direction and vector S j2 The directions are opposite; for points on the second plane other than the second roller shaft, vector S j1 Direction and vector S j2 The directions are opposite; that is, vector S j1 and vector S j2 In opposite directions, or, vector S j1 and vector S j2 All are equal to zero vectors.

[0358] In the direction perpendicular to the reference direction, "partial cancellation" means:

[0359] There exists at least one point in the first plane such that (x) i2 -x i1 ) 2 <(x i1 -x i ) 2 Meanwhile, (x) i2 -x i ) 2 <(x i1 -x i ) 2 ;

[0360] or,

[0361] There exists at least one point in the second plane that satisfies (x) j2 -x j1 ) 2 <(x j1 -x j ) 2 Meanwhile, (x) j2 -x j ) 2 <(x j1 -x j ) 2 .

[0362] In the direction perpendicular to the reference direction, "complete cancellation" means:

[0363] For any point on the first plane, satisfying (x i2 -x i1 ) 2 ≥(x i1 -x i ) 2 Meanwhile, vector T i1 and vector T i2 Vectors with opposite directions or both equal to zero;

[0364] and,

[0365] For any point on the second plane, (x) j2 -x j1 ) 2 ≥(x j1 -x j ) 2 Meanwhile, vector T j1 and vector T j2 Vectors with opposite directions or both equal to zero.

[0366] Understandably, "vector T" i1 and vector T i2 "Vectors with opposite directions or both equal to zero" can be expressed as: "Vector T" i1 Direction and vector T i2 The direction is opposite, or, vector T i1 and vector T i2 "All are equal to zero vectors".

[0367] Understandably, "vector T" j1 and vector T j2 "Vectors with opposite directions or both equal to zero" can be expressed as: "Vector T" j1 Direction and vector T j2 The direction is opposite, or, vector T j1 and vector T j2 "All are equal to zero vectors".

[0368] It is understandable that, based on the above further explanation of "complete cancellation" and "partial cancellation" in the reference direction, it can be concluded that, as Figure 20 As shown, in the floating control steps, the first plane and the second plane move from the reference plane to plane Ψ respectively. 0-1 Location and plane Ψ 0-2 Location:

[0369] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 1-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ1-2 In this case, the "change of the placement plane by the compensation control steps" partially offsets the "change of the placement plane by the floating control steps" in the reference direction.

[0370] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 2-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ 2-2 Location; Plane Ψ 2-1 and plane Ψ 2-2 Symmetrical about the origin of the coordinate system; therefore, "the change of the placement plane by the compensation control steps" partially offsets "the change of the placement plane by the floating control steps" in the reference direction;

[0371] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 3-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ 3-2 Location; Plane Ψ 3-1 and plane Ψ 3-2 All coincide with the reference plane; therefore, the "change of the placement plane by the compensation control steps" completely cancels out the "change of the placement plane by the floating control steps" in the reference direction.

[0372] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 4-1 At that point, the second plane is from plane Ψ 2-0 The point moves to plane Ψ 4-2 If the change in the placement plane caused by the compensation control steps is completely offset by the change in the placement plane caused by the floating control steps in the reference direction, then the change in the placement plane caused by the compensation control steps is completely offset by the floating control steps in the reference direction.

[0373] It should be noted that, based on the above further explanation of "complete cancellation" in the direction perpendicular to the reference direction and "partial cancellation" in the direction perpendicular to the reference direction, it can be understood that, as Figure 20 As shown, in the floating control steps, the first plane and the second plane move from the reference plane to plane Ψ respectively. 0-1 Location and plane Ψ 0-2 Point Nip moves from the origin to point N0:

[0374] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 1-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ 1-2If point Nip moves from point N0 to point N1, then the "change of the placement plane by the compensation control step" partially cancels out the "change of the placement plane by the floating control step" in the direction perpendicular to the reference direction.

[0375] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 2-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ 2-2 Point Nip moves from point N0 to point N2; plane Ψ 2-1 and plane Ψ 2-2 Symmetric about the origin, point N2 coincides with the origin; therefore, the "change of the placement plane by the compensation control steps" completely cancels out the "change of the placement plane by the floating control steps" in the direction perpendicular to the reference direction.

[0376] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 3-1 At that point, the second plane is from plane Ψ 0-2 The point moves to plane Ψ 3-2 At point N0, point Nip moves to point N3; plane Ψ 3-1 and plane Ψ 3-2 Point N3 coincides with the origin of the coordinate system and is aligned with the reference plane. Therefore, the "change of the placement plane by the compensation control steps" completely cancels out the "change of the placement plane by the floating control steps" in the direction perpendicular to the reference direction.

[0377] If the compensation control steps cause the first plane to move from plane Ψ 0-1 The point moves to plane Ψ 4-1 At that point, the second plane is from plane Ψ 2-0 The point moves to plane Ψ 4-2 If point Nip moves from point N0 to point N4, then the "change of the placement plane by the compensation control steps" completely cancels out the "change of the placement plane by the floating control steps" in the direction perpendicular to the reference direction.

[0378] It should be noted that, as Figure 20 The image shows an example of a horizontal, equal-diameter, twin-roll thin strip casting machine.

[0379] It should be noted that, as Figure 20 As shown, the distance from point N1 to the reference line is less than the distance from point N0 to the reference line.

[0380] It should be noted that "full offset" and "partial offset" can be defined according to the actual process conditions, for example:

[0381] During the preparation process, if the first roller and the second roller do not change position in the direction perpendicular to the reference direction, or if the position change of the first roller and the second roller in the direction perpendicular to the reference direction is so small as to be negligible, then "complete cancellation" can be considered as "complete cancellation in the reference direction".

[0382] During the manufacturing process, if the positions of the first roller and the second roller both change non-negligibly in the direction of reference and in the direction perpendicular to the reference direction, "complete cancellation" should be considered as "complete cancellation in the reference direction and complete cancellation in the direction perpendicular to the reference direction", and "partial cancellation" should be considered as "partial cancellation in the reference direction or partial cancellation in the direction perpendicular to the reference direction".

[0383] It is understandable that, even without interpreting "complete offset" and / or "partial offset" in this patent application, those skilled in the art can directly and unambiguously determine the meaning of "complete offset" and / or "partial offset"; because the purpose of "complete offset" and / or "partial offset" is clear and unambiguous; the purpose of "complete offset" and / or "partial offset" is to filter out roll gap floating directions that are detrimental to process stability and / or billet quality; the difficulty of this patent application lies in understanding why "roll gap floating directions that are detrimental to process stability and / or billet quality" should be "filtered," rather than how to understand "complete offset and / or partial offset"; without the systematic experiments conducted by the inventors based on the first-proposed "tracer method" and "Kiss angle measurement method," and the eventual discovery of the dual properties of the Kiss angle, those skilled in the art would never have understood why "roll gap floating directions that are detrimental to process stability and / or billet quality" should be "filtered."

[0384] It is understandable that "filtering out roll gap floating directions that are detrimental to process stability and / or billet quality" can also be expressed as "removing roll gap floating directions that are detrimental to process stability and / or billet quality".

[0385] It is understandable that "filtering the direction of roll gap floating that is detrimental to process stability and / or billet quality" can also be expressed as "removal" or "rejection".

[0386] Furthermore, a roll gap control method for a twin-roll thin strip process, wherein the compensation control step is initiated when the current position of the first roll and / or the second roll deviates from the reference position in the reference direction by a distance threshold greater than or equal to a distance threshold.

[0387] It should be noted that, under normal circumstances, the reference plane is regarded as the "reference position"; as those skilled in the art can understand, the reference position can also be other fixed positions in order to determine the "distance threshold".

[0388] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 0 to 5 micrometers.

[0389] It should be noted that "the distance threshold is in the range of 0 to 5 micrometers" includes the endpoints 0 and 5 micrometers; that is, in the present invention patent application documents, unless otherwise specified, "in the range of... to..." includes the endpoints.

[0390] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 5 to 20 micrometers.

[0391] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 20 to 50 micrometers.

[0392] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 50 to 200 micrometers.

[0393] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 200 to 500 micrometers.

[0394] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the reference plane is the reference position, and the distance threshold is in the range of 0.5 to 270 mm.

[0395] It should be noted that "the distance threshold is in the range of 0.5 to 270 mm", where "270 mm" is a value obtained by the inventors based on a horizontal equal-diameter twin-roll thin strip casting machine with a roll diameter of 1000 mm.

[0396] It should be noted that, let 's' be the distance by which the current position deviates from the reference position in the reference direction, such as... Figure 21 As shown, establish a two-dimensional rectangular coordinate system, with the origin at the Nip point in its natural state; the reference line is the Y-axis, with its positive direction opposite to the reference direction; in its natural state, the straight line passing through the Nip point and perpendicular to both the Y-axis and the roller axis is the X-axis, with its positive direction as shown in the diagram. Figure 21 As shown; let the coordinates of the second roller shaft at the current position be (X... 当前 Y 当前 Let the coordinates of the second roller shaft at "reference position one" be (X).预设1 Y 基准1 Let the coordinates of the second roller shaft at "reference position two" be (X). 预设2 Y 基准2 Let the coordinates of the second roller shaft at "reference position three" be (X). 预设3 Y 基准3 Therefore, the distance s1 = |Y| between the current position and the reference position in the reference direction is... 当前 -Y 基准1 The current position deviates from "reference position two" by a distance s2 = |Y|. 当前 -Y 基准2 The current position deviates from "reference position three" by a distance s3 = |Y. 当前 -Y 基准3 |

[0397] It is understandable that the position where the distance from the reference position in the reference direction reaches a distance threshold is called the threshold position.

[0398] Furthermore, in a roll gap control method for a twin-roll thin strip process, in the compensation control step, the roll system is controlled to move to a preset position so as to change the placement plane, thereby partially or completely offsetting the change in the placement plane caused by the floating control step.

[0399] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the preset position includes one or more of the following positions:

[0400] The initial position of the roller system;

[0401] The first roller and / or the second roller are positioned at a predetermined location on the twin-roll thin strip casting machine;

[0402] The first roller and / or the second roller are positioned within a predetermined range on the twin-roll thin strip casting machine.

[0403] Understandably, the purpose of setting a preset position is to control the range of roller movement according to the actual situation, so as to use the roller movement (or, the compensation control step) to partially or completely offset the change in the distance between the relative reference positions of the first roller and / or the second roller during the roller gap floating process (or, the floating control step).

[0404] Understandably, the preset position and the reference position can be set to the same position.

[0405] Understandably, the preset position can be set to the initial position or to a range, such as the area between the initial position and the threshold position.

[0406] It should be noted that the initial position refers to the position of the first roller and / or the second roller in its natural state.

[0407] It should be noted that the initial position can also be called the original position; for a horizontal equal-diameter twin-roll thin strip casting machine, when the first roll body and / or the second roll body are in the initial position, the first roll body and / or the second roll shaft are located in the reference plane.

[0408] Furthermore, a roll gap control method for a twin-roll thin strip process, wherein the floating control step includes the steps described above in all the roll gap control methods for twin-roll thin strip processes.

[0409] Understandably, when only or as many roll gap floating directions favorable to the preparation process occur, the placement plane will continuously change. Since the "change of placement plane by the roller system movement" in the compensation control step offsets the "change of placement plane by the relative movement between the two rollers" in the float control step, the drawback of "in the process of bidirectional periodic or bidirectional non-periodic roll gap floating in traditional technology, where one direction of roll gap floating and the other direction of roll gap floating are indispensable, and the changes in placement plane by the relative movement between the two rollers corresponding to each direction must cancel each other out in order for the process to proceed" is avoided. The relative movement between the two rollers ensures that the roll gap only floats in directions favorable to the preparation process and determined by the material properties.

[0410] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the roll system motion includes one or more of the following motion modes:

[0411] The roller system rotates about the second roller shaft;

[0412] The roller system rotates around the first roller shaft;

[0413] The roller system moves linearly relative to the ground in a direction perpendicular to the reference plane;

[0414] The roller system moves linearly relative to the ground in a direction oblique to the reference plane;

[0415] The roller system rotates about any axis parallel to either the first roller shaft or the second roller shaft.

[0416] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, the timing relationship between the floating control step and the compensation control step includes one or more of the following:

[0417] The floating control steps and the compensation control steps are performed sequentially.

[0418] The floating control steps and the compensation control steps are initiated sequentially and partially overlapped.

[0419] The floating control step and the compensation control step are performed simultaneously, but the changes to the placement plane by the floating control step and the compensation control step are not synchronized.

[0420] The floating control step and the compensation control step are performed simultaneously, and the changes to the placement plane are performed synchronously by the floating control step and the compensation control step.

[0421] It is understood that "the floating control steps and the compensation control steps are performed sequentially" means that the floating control steps are executed first, and then the compensation control steps are executed, and the floating control steps and the compensation control steps do not occur simultaneously; or, the compensation control steps are executed first, and then the floating control steps are executed, and the floating control steps and the compensation control steps do not occur simultaneously.

[0422] It is understood that "the floating control step and the compensation control step are initiated sequentially and partially overlapped" means that the compensation control step is executed during a portion of the process of the floating control step; or, the floating control step is executed during a portion of the process of the compensation control step.

[0423] It is understood that "the changes to the placement plane caused by the floating control steps and the compensation control steps are not synchronized" means that "the changes to the placement plane caused by the floating control steps" and "the changes to the placement plane caused by the compensation control steps" partially cancel each other out, and the placement plane changes relative to the ground.

[0424] It is understood that "the changes to the placement plane caused by the floating control steps and the compensation control steps are performed synchronously" means that the changes to the placement plane caused by the floating control steps and the compensation control steps completely cancel each other out. Although there is relative movement between the two rollers and the roller system also moves, the placement plane of the roller system does not change. In other words, the relative movement between the two rollers causes the placement plane to change, and the movement of the roller system also causes the placement plane to change. However, the changes to the placement plane caused by the relative movement between the two rollers and the movement of the roller system completely cancel each other out, and the placement plane does not change relative to the ground.

[0425] It is understandable that, such as Figure 20 As shown, assume that at some point t during the preparation process... es Both rollers are located on the reference plane, with the first roller located at point O. 1-3 At point O, the second roller shaft is located. 2-3Location; at t es To t ee At any given moment, the floating control step and the compensation control step occur simultaneously, and the first roller shaft is always located at point O. 1-3 At point O, the second roller shaft is always located. 2-3 At this point, the placement plane always coincides with the reference plane; that is, at t es To t ee At time t, "the floating control step and the compensation control step change the placement plane synchronously"; therefore, at t es To t ee At any given moment, the placement plane appears unchanged. In the reference direction, the changes to the placement plane caused by the "float control steps" and the "compensation control steps" completely cancel each other out.

[0426] For any point on the first plane, (y i2 -y i1 ) 2 =(y i1 -y i ) 2 Meanwhile, vector S i1 and vector S i2 All are equal to zero vectors;

[0427] and,

[0428] For any point on the second plane, (y j2 -y j1 ) 2 =(y j1 -y j ) 2 Meanwhile, vector S j1 and vector S j2 All are equal to zero vectors.

[0429] Understandably, during the preparation process, the compensation control step can be activated whenever the floating control step causes a change in the placement plane, so that the change in the placement plane caused by the compensation control step can partially or completely offset the change in the placement plane caused by the floating control step.

[0430] It should be noted that when "the floating control step and the compensation control step are performed simultaneously, and the floating control step and the compensation control step change the placement plane synchronously", the distance threshold should be considered to be equal to zero, and the preset position, the threshold position and the current position coincide.

[0431] It is understandable that when the floating control step and the compensation control step are performed sequentially, the initiation conditions of the compensation control step can be set according to the actual process requirements. For example, the initiation and compensation method of the compensation control step can be manually controlled; alternatively, the compensation control step can be triggered by setting the threshold positions of the first roller, the second roller, and the placement plane, etc. The setting method is on demand and will not be elaborated here.

[0432] Furthermore, a method for controlling the roll gap in a twin-roll thin strip process, wherein the preset position is variable or fixed.

[0433] It is understandable that in actual production, since the factors affecting process stability and / or billet quality are multifaceted and complex, the preset position can be set according to the actual situation.

[0434] It is understandable that in actual production, if the compensation control steps are performed manually, the accuracy of manual control depends on experience and / or the state of the human body and / or environmental factors. Therefore, when the roller system is manually operated, the actual position reached by the roller system will deviate more or less from the preset position.

[0435] Furthermore, in a method for controlling the roll gap in a twin-roll thin strip process, when the roll system rotates, the absolute value of the angular velocity of the roll system is in the range of 0.1 to 10 degrees / second.

[0436] Furthermore, a roll gap control method for a twin-roll thin strip process, wherein the frequency of the compensation control step is in the range of 0.01 to 10 Hz.

[0437] It is understandable that the frequency of occurrence of the compensation control steps refers to the number of times the compensation control steps occur per unit time.

[0438] It is understood that "the frequency of occurrence of the compensation control step" can be expressed as "the frequency of relative motion between the roller system and the ground" or "the number of times relative motion between the roller system and the ground occurs per unit time".

[0439] It is understandable that when discussing the frequency of occurrence of the aforementioned "compensation control steps", "one relative movement between the roller system and the ground" is considered as "one compensation control step".

[0440] Furthermore, in the roll gap control method of the twin-roll thin strip process, the floating control step includes the steps of the roll gap control method of the twin-roll thin strip process as described in any of the preceding claims.

[0441] It is understandable that the stability of the roller clamping force is crucial for the efficient and stable operation of the preparation process and / or the quality of the billet. The roller gap control method for the twin-roll thin strip process proposed in this patent application has the unique advantage of not causing bidirectional fluctuations in the roller clamping force compared to the traditional two-way floating roller gap method. At the same time, the relative movement between the two rollers will change the placement plane of the roller system. Therefore, the "change of the placement plane by the roller system movement" is used to offset the "change of the placement plane by the relative movement between the two rollers" in a timely manner, so as to allow the continuous and stable operation of the billet preparation process and / or ensure the quality of the billet.

[0442] The present invention also provides a twin-roll thin strip casting machine apparatus for the roll gap control method applied to the above-mentioned twin-roll thin strip process, wherein a roll system is disposed on the twin-roll thin strip casting machine apparatus; the roll system includes a first roll body and a second roll body; the roller shaft of the first roll body is a first roller shaft, and the roller shaft of the second roll body is a second roller shaft; the plane in which the first roller shaft and the second roller shaft are located is called the placement plane of the roll system; the roll system is movably disposed on the twin-roll thin strip casting machine apparatus as a whole through a first kinematic pair, so that the roll system moves on the twin-roll thin strip casting machine apparatus in a manner of overall movement; the first roll body and / or the second roll body are movably disposed on the twin-roll thin strip casting machine apparatus through a second kinematic pair, so that relative movement occurs between the first roll body and the second roll body; wherein, the change of the placement plane by the movement of the roll system and the change of the placement plane by the relative movement between the first roll body and the second roll body are partially or completely canceled out.

[0443] It should be noted that there are several equivalent ways to express the concept of kinematic pairs, including:

[0444] "The motion of A on B constitutes a kinematic pair";

[0445] "A and B form a kinematic pair";

[0446] "The movement of A on B forms a kinematic pair (or connection)."

[0447] "The active connection between A and B that generates relative motion forms a kinematic pair."

[0448] It is understandable that "A" and "B" both represent components and can be replaced with specific component names.

[0449] Furthermore, in the twin-roll thin strip casting machine apparatus, the first kinematic pair includes at least one of a sliding pair and a rotating pair.

[0450] Furthermore, the twin-roll thin strip casting machine further includes a first main shaft, a second main shaft, a first bearing housing, a second bearing housing, a first inner track, and a first outer track; the first main shaft of the first roll is housed in the first bearing housing; the second main shaft of the second roll is housed in the second bearing housing; the first bearing housing is movably mounted on the first inner track; and the first inner track is movably mounted on the first outer track.

[0451] Furthermore, in the twin-roll thin strip casting machine apparatus, the second kinematic pair includes one or more of the following kinematic pairs:

[0452] A kinematic pair that causes the first roller to rotate around the second roller shaft;

[0453] A kinematic pair that causes the second roller to rotate around the first roller shaft;

[0454] A kinematic pair that causes the direction of the velocity of the first roller and / or the direction of the velocity of the second roller to move in a direction perpendicular to the reference plane;

[0455] A kinematic pair that causes the direction of the velocity of the first roller and / or the direction of the velocity of the second roller to move in a direction oblique to the reference plane;

[0456] A kinematic pair that causes the first roller to rotate about any axis parallel to the first roller shaft;

[0457] A kinematic pair that causes the second roller to rotate about any axis parallel to the second roller shaft.

[0458] The present invention has the following beneficial effects:

[0459] The unidirectional floating of the roll gap has the unique advantage of completely avoiding the bidirectional fluctuation of the roll clamping force in traditional methods, which is of vital importance to both process stability and billet quality.

[0460] Unidirectional roll gap and fixed opening degree can greatly improve the uniformity of billet thickness and / or the uniformity of billet structure, while significantly improving process stability.

[0461] The technical solution proposed in this patent application can promote the timely collapse of the long-range shear-thinning interface to reduce the pressure peak in the molten pool, prevent side sealing plate leakage, side sealing plate damage, jamming, breakage, large cracks, etc. caused by excessive peak pressure in the molten pool due to the natural collapse of the long-range shear-thinning interface, and enhance process stability.

[0462] The technical solution proposed in this patent application can prevent the molten pool pressure from connecting with the unsolidified core of the billet exiting the molten pool, thereby reducing or avoiding the probability of defects such as wrinkles, cracks, "ridges", "snake eggs" and "egg pancakes", and improving the quality of the billet.

[0463] The technical solution proposed in this patent application can improve the synchronization of the molten pool-like periodic transmission behavior along the roller axis, reduce or avoid the occurrence of defects such as "ridge", "snake egg" and "egg pancake", and improve the quality of the billet;

[0464] The technical solution proposed in this patent application can reduce roller wear, extend roller service life, and reduce production costs;

[0465] The technical solution proposed in this patent application can reduce the processing accuracy requirements of key components, including rollers, thereby reducing equipment manufacturing and / or maintenance costs.

[0466] When a contact-type side sealing device is required, the technical solution proposed in this patent application can improve the service life of the side sealing device and reduce production costs. The contact-type side sealing device includes a refractory side sealing plate.

[0467] The technical solution proposed in this patent application can transform "high-dimensional motion" into "low-dimensional motion", reducing the equipment requirements for implementing roll gap floating and enhancing process robustness.

[0468] Eliminate the "bright lines" that run through the billet;

[0469] Reduce vibration of twin-roll thin strip casting machines;

[0470] Improving the cooling efficiency of the roller body and enhancing the surface quality of the billet can reduce porosity defects on the surface of the billet.

[0471] Prepare small batches of high-end materials;

[0472] It is expected to enable the preparation of thin strips of metallic materials with a relatively wide two-phase region;

[0473] It holds promise for the fabrication of metallic thin strips with extremely narrow two-phase regions;

[0474] It is expected to revolutionize the way metal strips are prepared, thereby bringing about changes in traditional fields and having an immeasurable impact on the progress of human society.

[0475] The technical solutions proposed in this patent application can be used to prepare steel strips, non-ferrous metal strips, etc. using a twin-roll thin strip process, such as: multilayer thin strips (e.g., copper-aluminum composite thin strips; or titanium-aluminum composite thin strips), aluminum alloy thin strips (e.g., 7-series aluminum alloys; or 6-series aluminum alloys), silicon steel thin strips (e.g., silicon steel with a silicon content of more than 5%), Invar alloy thin strips, copper alloy thin strips (e.g., Cu-15Ni-8Sn; or Cu-9Ni-6Sn), high-entropy alloy thin strips, multilayer bars, multilayer tubes, and multilayer plates (e.g., multilayer alloy plates with a thickness of 10 mm). Attached Figure Description

[0476] Figure 1 The diagram illustrates the traditional understanding of the solidification process of the billet shell within the molten pool by those skilled in the art.

[0477] Figure 2 The figure shown is an actual experimental result obtained by implementing the Kiss angle measurement method using a laboratory twin-roll thin strip casting machine.

[0478] Figure 3 The diagram shows a brief schematic of the experimental results obtained by implementing the tracer method and the Kiss angle measurement method using a laboratory twin-roll thin strip casting machine.

[0479] Figure 4 The diagram shows a schematic of the existing zero-angle roll gap bidirectional floating method.

[0480] Figure 5 The diagram shown is a schematic of the existing vertical roll gap bidirectional floating method.

[0481] Figure 6 The diagram shown is a schematic of the bidirectional floating method of inclined roll gap in the prior art.

[0482] Figure 7 The diagram shows a schematic of a bidirectional floating method for a fixed opening roller gap in the prior art.

[0483] Figure 8 The diagram shows the molten pool transport process in a quasi-periodic transport process proposed by the inventors, where there is no significant rolling process or no rolling process at all.

[0484] Figure 9 The diagram shows the formation and convergence of long-range shear-thinning interfaces and the generation of Kiss points / corners in a quasi-periodic transport process in a molten pool, as proposed by the inventors.

[0485] Figure 10 The diagram shows the development of the long-range shear-thinning interface and the Kiss angle in the quasi-periodic transport process in the molten pool proposed by the inventors.

[0486] Figure 11 The diagram shows the long-range shear-thinning interface collapse and Kiss point / corner disappearance in the quasi-periodic transport process in the molten pool proposed by the inventors.

[0487] Figure 12 The diagram shows a schematic of the intense rolling process in the molten pool, which is a quasi-periodic transport process proposed by the inventors.

[0488] Figure 13 The diagram shows a detailed transport behavior when a long-range shear-thinning interface and a Kiss point / corner exist in the molten pool.

[0489] Figure 14 The diagram shown is a schematic of point C, u0, and streamlines in the molten pool obtained by the inventors based on the enthalpy-porous mathematical model.

[0490] Figure 15 The diagram shows the placement plane, reference plane, first roll, second roll, Nip point, first roll shaft, second roll shaft, preparation direction, reference speed, reference direction, and reference line of a horizontal equal-diameter twin-roll thin strip casting machine under different conditions.

[0491] Figure 16 The diagram shown illustrates the "first rotation" of the placement plane caused by the relative motion between the two rollers, using a horizontal equal-diameter twin-roll thin strip casting machine as an example.

[0492] Figure 17 The diagram shown illustrates that "the two first rotations occur consecutively" using a horizontal equal-diameter twin-roll thin strip casting machine as an example.

[0493] Figure 18 The diagram shown illustrates the rotation of the placement plane caused by a single relative motion between two rollers, including the first rotation and the second rotation.

[0494] Figure 19 The diagram shown illustrates the “two-dimensional motion” and “one-dimensional motion” of the moving roller.

[0495] Figure 20 The diagram shown illustrates the concepts of "partial offset" and "full offset".

[0496] Figure 21 The diagram illustrates the method for calculating the distance of the current position from the reference position in the reference direction.

[0497] Figure 22 The diagram shown is a schematic diagram of the starting moment of the floating control step in Embodiment 1 of the present invention.

[0498] Figure 23The diagram shows the end time of the floating control step and the start time of the compensation control step in Embodiment 1 of the present invention.

[0499] Figure 24 The diagram shown is a schematic diagram of the compensation control step at the end of Embodiment 1 of the present invention.

[0500] Figure 25 The diagram shown is a schematic representation of the starting moment of the first floating control step in Embodiment 2 of the present invention.

[0501] Figure 26 The diagram shows the end time of the first floating control step and the start time of the second floating control step in Embodiment 2 of the present invention.

[0502] Figure 27 The diagram shows the end time of the second floating control step and the start time of the third floating control step in Embodiment 2 of the present invention.

[0503] Figure 28 The diagram shows the end time of the third floating control step and the start time of the fourth floating control step in Embodiment 2 of the present invention.

[0504] Figure 29 The diagram shows the end time of the fourth floating control step and the start time of the compensation control step in Embodiment 2 of the present invention.

[0505] Figure 30 The diagram shown is a schematic representation of the end time of the compensation control step in Embodiment 2 of the present invention.

[0506] Figure 31 The diagram shown is a schematic representation of the starting moment of the first floating control step in Embodiment 3 of the present invention.

[0507] Figure 32 The diagram shows the end time of the first floating control step and the start time of the first compensation control step in Embodiment 3 of the present invention.

[0508] Figure 33 The diagram shows the end time of the first compensation control step and the start time of the second floating control step in Embodiment 3 of the present invention.

[0509] Figure 34 The diagram shows the end time of the second floating control step and the start time of the second compensation control step in Embodiment 3 of the present invention.

[0510] Figure 35The diagram shown is a schematic representation of the end time of the second compensation control step in Embodiment 3 of the present invention.

[0511] Figure 36 The diagram shown is a schematic representation of the starting moment of the first floating control step in Embodiment 4 of the present invention.

[0512] Figure 37 The diagram shows the end time of the first floating control step and the start time of the second floating control step in Embodiment 4 of the present invention.

[0513] Figure 38 The diagram shows the end time of the second floating control step and the start time of the third floating control step in Embodiment 4 of the present invention.

[0514] Figure 39 The diagram shows the end time of the third floating control step and the start time of the fourth floating control step in Embodiment 4 of the present invention.

[0515] Figure 40 The diagram shown is a schematic representation of the end time of the fourth floating control step in Embodiment 4 of the present invention.

[0516] Figure 41 The diagram shown is a schematic diagram of the first and second rollers in their natural state according to Embodiment 5 of the present invention.

[0517] Figure 42 The diagram shown is a schematic diagram of the steps of multiple floating control in Embodiment 5 of the present invention.

[0518] Figure 43 The diagram shown is a schematic diagram of the placement plane undergoing multiple first rotations in Embodiment 5 of the present invention.

[0519] Figure 44 The diagram shown is a schematic representation of the starting moment of the first floating control step in Embodiment 6 of the present invention.

[0520] Figure 45 The diagram shows the end time of the first floating control step and the start time of the second floating control step in Embodiment 6 of the present invention.

[0521] Figure 46 The diagram shows the end time of the second floating control step and the start time of the third floating control step in Embodiment 6 of the present invention.

[0522] Figure 47 The diagram shows the end time of the third floating control step and the start time of the fourth floating control step in Embodiment 6 of the present invention.

[0523] Figure 48 The diagram shown is a schematic representation of the end time of the fourth floating control step in Embodiment 6 of the present invention.

[0524] Figure 49 The diagram shown is a schematic of a “complete process” in Embodiment 7 of the present invention, consisting of three floating control steps and one compensation control step.

[0525] Figure 50 The diagram shows that in Embodiment 8 of the present invention, multiple first rotations occur continuously, and during the relative motion between the two rollers between two consecutive first rotations, the effective speed is always equal to zero.

[0526] Figure 51 The diagram shown is a schematic diagram of the two first rotations occurring consecutively in Embodiment 9 of the present invention.

[0527] Figure 52 The diagram shown is a schematic diagram of multiple first rotations occurring continuously and the roll gap opening being constant in Embodiment 10 of the present invention.

[0528] Figure 53 The diagram shown is a partial structural diagram of the twin-roll thin strip casting machine device in its natural state according to Embodiment 11 of the present invention.

[0529] Figure 54 The image shown is from Embodiment 11 of the present invention. Figure 53 A schematic diagram of the end moment of the floating control step in the medium twin-roll thin strip casting machine device.

[0530] Figure 55 The image shown is from Embodiment 11 of the present invention. Figure 54 A schematic diagram of the end time of the compensation control step in the medium twin-roll thin strip casting machine.

[0531] Figure 56 The diagram shown is a partial structure of a twin-roll strip casting machine in its natural state according to another embodiment.

[0532] Figure 57 The diagram shown is a partial structure of a twin-roll strip casting machine in its natural state according to another embodiment.

[0533] The correspondence between the figure numbers in the following figures is as follows:

[0534] 1. First roller body, 2. Second roller body, 3. Roll gap, 4. Long-range shear thinning interface, 5. Molten pool, 6. Flow distribution device, 7. Billet body, 8. Reference plane, 9. Gravity direction, 10. First main shaft, 11. Second main shaft, 12. First bearing seat, 13. Second bearing seat, 14. First inner track, 15. First outer track, 16. Second outer track, 17. Second inner track, 18. Motion trajectory. Detailed Implementation

[0535] The invention will now be described in further detail with reference to the accompanying drawings.

[0536] For ease of explanation, please refer to the following: Figure 15 In the present invention patent application, a plane Ω is arbitrarily selected, which is perpendicular to the first roller shaft; in the natural state, the intersection points of the first roller shaft and the second roller shaft with the plane Ω (or the paper surface) are point O1 and point O2, respectively; the rotation is positive when it is perpendicular to the paper surface and inward, and the angle of clockwise rotation of the ray (or plane) is negative, the angle of counterclockwise rotation of the ray (or plane) is positive, and the angle of no rotation of the ray (or plane) is zero.

[0537] All embodiments in this patent application use a horizontal equal-diameter twin-roll thin strip casting machine. Therefore, in the following embodiments, the reference direction is the same as the gravity direction 9.

[0538] In addition, in the following embodiments, α, β, ω, ϖ, u, and θ all represent vectors; |α|, |β|, |ω|, |ϖ|, |u|, and |θ| represent the absolute value (or magnitude) of the corresponding vector. Example 1:

[0539] Embodiment 1 of this invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figures 22 to 24 As shown.

[0540] In Embodiment 1 of the present invention, the floating control steps include: controlling a relative movement between the two rollers to cause a first rotation of the placement plane; during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero, that is, the direction of the effective speed is always opposite to the preparation direction; that is, a relative movement between the two rollers is a floating control step; a floating control step generates a first rotation; the floating control step stops when the current position of the first roller 1 deviates from the reference position in the reference direction by a distance greater than or equal to a distance threshold.

[0541] As a further improvement, in Embodiment 1 of the present invention, the compensation control steps include: controlling the roller system to move on the twin-roll thin strip casting machine to partially or completely offset the "change in the placement plane caused by the relative movement between the two rollers" in the floating control steps; the roller system movement process does not cause a change in the relative position between the two rollers, that is, the floating process of the roll gap 3 is not affected by the roller system movement process; the compensation control steps are initiated when the current position of the first roller 1 deviates from the reference position in the reference direction by a distance threshold greater than or equal to the reference position; the compensation control steps are stopped after the first roller 1 reaches the preset position.

[0542] In Embodiment 1 of the present invention, the reference plane 8 is set to a preset position.

[0543] In Embodiment 1 of the present invention, the reference plane 8 is set as the reference position.

[0544] It is understood that in other implementations, the "preset position" and / or "reference position" may be set at different locations.

[0545] In Embodiment 1 of the present invention: based on the floating characteristics of the roll gap 3, the "distance threshold" can be converted into (or equivalent to; or transformed into) the "angle threshold"; and the "angle threshold" is set to 0.5 degrees; that is, in one floating control step, the first roll 1 rotates around the second roll 2, and when the absolute value of the rotation angle is greater than or equal to 0.5 degrees, the floating control step is declared to stop.

[0546] In Embodiment 1 of this invention, it is clear to those skilled in the art that the drawing scale of the first roller 1, the second roller 2, and the roll gap 3 is only sufficient to clearly represent the relative motion and / or roller system motion between the two rollers involved in the patent application of this invention; typically, the diameter of the roller is much larger than the opening of the roll gap 3. For example, in the process of producing steel strip using a constant diameter twin-roll thin strip casting machine, the diameter of the roller is in the range of 400 to 1000 mm, but the opening of the roll gap 3 is in the range of 0.5 to 3 mm.

[0547] In general, when preparing a metal blank 7 directly using liquid metal, there are some different opinions in the field regarding the upper limit of the roll gap 3 opening. However, the roll gap 3 opening mentioned in the publicly available information that the inventor has been able to find to date is all below 8 mm. In fact, the upper limit of the roll gap 3 opening attempted in industrial practice cannot exceed 3 mm, while the diameter of the roll body is at least 400 mm. Therefore, whether the roll gap 3 opening is "8 mm" or "3 mm", it is much smaller than the diameter of the roll body.

[0548] It is understandable that the subsequent embodiments are the same. The drawing scale of the first roller 1, the second roller 2, the roller gap 3, etc. is significantly different from the actual process. Only in this way can the features of the technical solution mentioned in the patent application document be clearly demonstrated.

[0549] It is understood that even without the above explanation of the drawing scale, those skilled in the art can directly and without doubt understand all the schematic diagrams involved in this patent application.

[0550] In Embodiment 1 of the present invention, if a "distance threshold" is used, the "distance threshold" can be set to [Sin0.5°×(R1+R2+D]. 开度 In the formula, R1 is the radius of the first roller 1, R2 is the radius of the second roller 2, and D... 开度 D is the opening of the roll gap 3; since the thickness of the prepared blank 7 is only on the order of millimeters, 开度 Much smaller than (R1+R2), therefore, under normal circumstances, the equation [Sin0.5°×(R1+R2+D] is correct. 开度 [Sin0.5°×(R1+R2)] can be considered approximately equal to [Sin0.5°×(R1+R2)], that is, [Sin0.5°×(R1+R2+D] 开度 )]≈[Sin0.5°×(R1+R2)].

[0551] In Embodiment 1 of the present invention, the opening degree of the roll gap 3 does not change during the preparation process, so as to allow the roll gap 3 to float at a constant opening degree.

[0552] like Figure 22 As shown at time t1, at the start of the floating control step, the two rollers are in their initial positions, and the placement plane is located at plane Ψ0; plane Ψ0 coincides with the reference plane 8.

[0553] like Figure 23 The figure shows the positions of the two rollers at time t2, the end time of the floating control step, and the start time of the compensation control step. At the end time of the floating control step, the two roller shafts are located at plane Ψ1. At the start time of the compensation control step, the placement plane is located at plane Φ0. Plane Φ0 coincides with plane Ψ1.

[0554] like Figure 24 The figure shows the end time of the compensation control step at time t3. The placement plane is located at plane Φ1, which is the preset position and coincides with the reference plane 8.

[0555] The angle between plane Φ0 (or plane Ψ1) and plane Φ1 (or plane Ψ0) is ω; the angle between plane Φ1 (or plane Ψ0) and plane Φ0 (or plane Ψ1) is ϖ.

[0556] It is understandable that the preset position is the target position of the roller system movement during the compensation control steps.

[0557] The steps of float control:

[0558] like Figures 22 to 23As shown, from time t1 to t2, the average angular velocity of the first roller 1 is θ1, and the average angular velocity of the second roller 2 is θ2; θ1 = -θ2 = -20 degrees / second. The first roller 1 rotates clockwise around the second roller axis by an angle ω, ω = -0.5 degrees. The instantaneous angular velocity and average angular velocity of the first roller 1 rotating around the second roller axis are α and α, respectively. t and α, α t <0, α=-0.1 degrees / second, t2-t1=|ω| / |α|=5 seconds; the placement plane rotates from plane Ψ0 to plane Ψ1, and the placement plane undergoes a first rotation. During this first rotation, the inner product of the floating speed and the preparation speed is always less than zero, that is, the direction of the effective speed is always opposite to the preparation direction; the floating control step actively increases the pressure in the molten pool 5 to suppress the excessive development of the Kiss angle and promote the renewal of the Kiss angle material.

[0559] The steps of compensation control:

[0560] like Figures 23 to 24 As shown, from time t2 to t3, the roller system rotates counterclockwise around the second roller axis by an angle ϖ, ω=-ϖ, and the instantaneous angular velocity and average angular velocity of the roller system rotating around the second roller axis are β and β, respectively. t And β, β=0.1 degrees / second; θ1=-20 degrees / second, θ2=-θ1+β=20.1 degrees / second, t3-t2=|ϖ| / |β|=5 seconds; the placement plane rotates from plane Φ0 to plane Φ1, and the placement plane rotates once; the compensation control steps do not actively change the pressure in the molten pool 5; since the "effective speed" must be caused only by the relative motion between the two rollers, in the compensation control steps, since there is no relative motion between the two rollers, the "floating speed" is always equal to zero, and the "effective speed" that can actively affect the pressure in the molten pool 5 is always equal to zero.

[0561] Embodiment 1 of the present invention is a periodic process, each cycle including a floating control step and a compensation control step; in one cycle, the floating control step occurs first, followed by the compensation control step; the "change of the placement plane by the compensation control step" and the "change of the placement plane by the floating control step" completely cancel each other out; the length of one cycle is 10 seconds; the occurrence frequency of the floating control step is 0.1 Hz; the occurrence frequency of the first rotation is 0.1 Hz.

[0562] It is understood that in other implementations, in a cycle, the compensation control step may occur first, followed by the float control step; the "change of the placement plane by the float control step" may be used to partially or completely offset the "change of the placement plane by the compensation control step".

[0563] like Figures 23 to 24As shown, in the compensation control step, although the roller system rotates around the second roller axis, |θ2|≠|θ1|; however, since the floating control step does not occur, there is no relative movement between the two rollers, and the roller gap 3 does not float. Therefore, both the "floating speed" and the "effective speed" are equal to zero. For an explanation of the "floating speed" and the "effective speed", please refer to the above text.

[0564] Optionally, the "angle threshold" is set in the range of 0.5 to 1.5 degrees. When the absolute value of the angle through which the first roller 1 rotates clockwise around the second roller shaft is in the range of 0.5 to 1.5 degrees, the floating control step is stopped at any time so as to facilitate the initiation of the subsequent compensation control step.

[0565] Optionally, in the floating control step, the first roller 1 rotates clockwise around the second roller 2, and the first roller 1 begins to deviate from the reference position; when the rotation angle of the first roller 1 around the second roller 2 reaches the angle threshold, the floating control step does not stop, and while the first roller 1 continues to rotate clockwise around the second roller 2, a compensation control step occurs to make the placement plane (or the first roller 1) return to the preset position.

[0566] In Embodiment 1 of the present invention, during the preparation process, the first rotation occurs continuously, and the relative movement between the two rollers causes the placement plane to rotate only in the first rotation; throughout the entire preparation process, the roller gap 3 floats only in a single direction.

[0567] It should be noted that, without compensation control steps: during the preparation process, one roller is always a moving roller, and the other roller is always a fixed roller, with the fixed roller's shaft remaining at a constant position relative to the ground; if the moving roller starts from reference plane 8 and rotates clockwise around the fixed roller without restriction; when the angle through which the moving roller rotates around the fixed roller exceeds 90 degrees, the roll gap 3 floats in a single direction. However, in reality, whether in laboratory experiments or industrial production, when the roller system does not move and the roles of the moving and fixed rollers do not interchange, the angle through which the moving roller rotates around the fixed roller cannot exceed 90 degrees, nor 45 degrees, nor even 15 degrees. Therefore, in this patent application, it is clear and unambiguous to determine "roll gap 3 floats in a single direction" based on whether "the direction of the effective speed is always the same as the preparation direction" or "the direction of the effective speed is always opposite to the preparation direction".

[0568] Optionally, during the preparation process, only one occurrence occurs. Figures 22 to 23 The process shown, that is, at the beginning of the preparation process, the placement plane is in the position as shown... Figure 22 As shown, at the end of the preparation process, the placement plane is in the position shown. Figure 23 The position shown; the first roller 1 from, as shown Figure 22The position shown is as follows Figure 23 The position shown is achieved by controlling the relative movement between the two rollers to ensure multiple first rotations occur consecutively; after the preparation process is completed, or before the next preparation process begins, the first roller 1 is adjusted to... Figure 22 The position shown is adjusted so that the placement plane is reset.

[0569] Optionally, such as Figure 22 As shown, during the preparation process, the floating control step and the compensation control step are performed simultaneously, and the "change of the placement plane by the floating control step" and the "change of the placement plane by the compensation control step" are performed synchronously; in the floating control step, the first roller 1 moves at an instantaneous angular velocity α t It rotates around the second roller shaft; simultaneously, in the compensation control step, the roller system moves at an instantaneous angular velocity β. t Rotating around the second roller shaft, α t =-β t Although the placement plane is always in Figure 22 The reference plane 8 is shown. However, since the "change of the placement plane by the floating control step" and the "change of the placement plane by the compensation control step" are performed simultaneously, both the floating control step and the compensation control step change the placement plane. However, the changes in the placement plane by the compensation control step and the floating control step cancel each other out in real time. Therefore, superficially, the placement plane appears unchanged. This method is suitable for preparing small batches of blanks 7 and can be used for small-batch preparation of high-end materials or laboratory experiments.

[0570] Alternatively, in other embodiments, such as Figures 22 to 23 As shown, in the floating control steps: one or more relative movements of any form occur between the two rollers, so that the placement plane moves from plane Ψ0 to plane Ψ1. Example 2:

[0571] Embodiment 2 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figures 25 to 30 As shown.

[0572] In Embodiment 2 of the present invention, during the preparation of the blank 7, the "multiple floating control steps" and the "single compensation control steps" are repeated sequentially; wherein, the "multiple floating control steps" stop when the current position of both rollers deviates from the reference position in the reference direction by a distance threshold greater than or equal to the reference position; the "single compensation control steps" are initiated when the current position of both rollers deviates from the reference position in the reference direction by a distance threshold greater than or equal to the reference position.

[0573] In Embodiment 2 of the present invention, the reference plane 8 is set as the reference position.

[0574] The steps of a single floating control include: controlling a relative motion between the two rollers to cause the placement plane to rotate once; during the first rotation, the inner product of the floating speed and the preparation speed is always less than zero, that is, the direction of the effective speed is always opposite to the preparation direction; and the placement plane changes.

[0575] The steps of a single compensation control include: controlling the roller system to move to a preset position; the preset positions of both rollers are on the reference plane 8; and the placement plane changes.

[0576] In Embodiment 2 of the present invention, the distance threshold is set to 10 millimeters.

[0577] like Figure 25 As shown in the "steps of multiple floating control", at the beginning of the first floating control step, both rollers are in the initial position; the placement plane is located at plane Ψ0; plane Ψ0 coincides with the reference plane 8.

[0578] like Figure 26 As shown in the “multiple floating control steps”, at the end of the first floating control step and at the beginning of the second floating control step, the first roller 1 deviates from the initial position, the second roller 2 is in the initial position, and the placement plane is oblique to the reference plane 8.

[0579] like Figure 27 As shown in the “multiple floating control steps”, at the end of the second floating control step and at the beginning of the third floating control step, the placement plane is located at plane Ψ1, and both rollers are deviated from their initial positions in the reference direction.

[0580] like Figure 28 As shown in the “multiple floating control steps”, at the end of the third floating control step and at the beginning of the fourth floating control step, both rollers deviate from their initial positions in the reference direction, and the placement plane intersects the reference plane 8 obliquely.

[0581] like Figure 29 As shown in the "multiple floating control steps", at the end of the fourth floating control step and at the beginning of the compensation control step, the current positions of the two rollers are both deviated from the reference position in the reference direction; the placement plane is located at plane Ψ2.

[0582] like Figure 30 As shown, at the end of the "one-time compensation control step", the placement plane is located at reference plane 8, and both rollers are located at the reference position.

[0583] The steps of the first float control in "Steps of Multiple Float Control" are as follows: Figures 25-26As shown: The first roller 1 rotates clockwise around the second roller shaft at an average angular velocity α1 without stopping by an angle ω. 1-1 The placement plane undergoes its first rotation; during this first rotation, the dot product of the floating velocity and the preparation velocity remains less than zero, and the direction of the effective velocity is opposite to the preparation direction; at the end of this floating control step, the angle between the placement plane and the reference plane 8 is ω. 1-1 .

[0584] The second floating control step in the "steps of multiple floating control" is as follows: Figures 26 to 27 As shown: The second roller 2 rotates counterclockwise around the first roller shaft at an average angular velocity α2 without stopping by an angle ω. 2-1 The placement plane undergoes a first rotation; during this first rotation, the inner product of the floating velocity and the preparation velocity is always less than zero, and the direction of the effective velocity is opposite to the preparation direction; at the end of this floating control step, the placement plane is located at plane Ψ1; Ψ1∥Ψ0.

[0585] The third floating control step in the "steps of multiple floating control" is as follows: Figures 27 to 28 As shown: The second roller 2 rotates counterclockwise around the first roller shaft at an average angular velocity α3 without stopping by an angle ω. 2-2 The placement plane undergoes its first rotation; during this first rotation, the dot product of the floating velocity and the preparation velocity remains less than zero, and the direction of the effective velocity is opposite to the preparation direction; at the end of this floating control step, the angle between the placement plane and the reference plane 8 is ω. 2-1 .

[0586] The steps of the fourth float control in "Steps of Multiple Float Control" are as follows: Figures 28 to 29 As shown: The first roller 1 rotates clockwise around the second roller shaft at an average angular velocity α4 without stopping by an angle ω. 1-2 The placement plane undergoes a first rotation; during this first rotation, the inner product of the floating velocity and the preparation velocity is always less than zero, and the direction of the effective velocity is opposite to the preparation direction; at the end of this floating control step, the placement plane is located at plane Ψ2; Ψ2∥Ψ1∥Ψ0.

[0587] After the fourth float control step in the "Steps of Multiple Float Control" is completed, as follows: Figure 29 As shown: Quadrilateral O 1-2 O 2-2 O2O1 is a rectangle, O 1-2 O1⊥O1O2,O 2-2 O2⊥O1O2.

[0588] The steps for the first to fourth floating controls in the "Steps of Multiple Floating Controls": The absolute value of the displacement vector D1 of the first roller 1 is line segment O1O 1-2 The length, and the direction from point O1 to point O. 1-2 At point O2O, the absolute value of the displacement vector D2 of the second roller 2 is the line segment O2O. 2-2 The length, and the direction from point O2 to point O. 2-2 Location; D1=D2; |D1|=|D2|=10 mm=distance threshold, the directions of displacement vector D1 and displacement vector D2 are both opposite to the reference direction.

[0589] In the "multiple floating control steps", during the movement between the two rollers, the effective speed is never zero, and the direction of the effective speed is always opposite to the preparation direction, so the roller gap 3 floats in a single direction.

[0590] In Embodiment 2 of the present invention, during the preparation process, multiple first rotations occur continuously, and the relative movement between the two rollers causes the placement plane to only undergo a first rotation; therefore, during the entire preparation process, the roller gap 3 only floats in a single direction.

[0591] The steps of compensation control, such as Figures 29 to 30 As shown: The roller system starts from the current position (or, the threshold position point O of the second roller 2). 2-2 The plane moves to the preset position, and the placement plane moves from plane Ψ2 to plane Ψ0.

[0592] In the compensation control step, the absolute value of the average speed u of the roller system is in the range of 0.01 to 0.2 m / s.

[0593] Optionally, the preset position of the two rollers is set at plane Ψ3; plane Ψ3 is located between plane Ψ2 and plane Ψ0, and Ψ3∥Ψ2∥Ψ1∥Ψ0; in the compensation control step, the roller system starts to move from the current position and moves to the preset position, and the placement plane changes.

[0594] Optionally, the preset positions of the two rollers are set at plane Ψ4; plane Ψ4 is located below plane Ψ0 (or, the preset position and the threshold position are located on different sides of the reference plane 8), and Ψ4∥Ψ2∥Ψ1∥Ψ0; in the compensation control step, the roller system starts to move from the current position and moves to the preset position, and the placement plane changes.

[0595] Optionally, the preset position of the two rollers is set at plane Ψ5; plane Ψ5 is an arbitrary plane that is parallel or oblique to the reference plane 8; in the compensation control step, the roller system starts to move from the current position and moves to the preset position, and the placement plane changes.

[0596] Optionally, the preset position varies in different compensation control steps.

[0597] like Figures 25 to 30 The diagram shows "a complete process"; "a complete process" is one cycle, which includes "multiple floating control steps" (or, four floating control steps) and "one compensation control step"; the change in the placement plane caused by one "compensation control step" completely cancels out the changes in the placement plane caused by multiple consecutive "floating control steps"; in one preparation process, "a complete process" can be executed only once, or "a complete process" can be executed repeatedly.

[0598] During the preparation process, the opening of the roll gap 3 remains unchanged during the relative movement between the two rollers, so that the floating of the roll gap 3 is "unidirectional fixed opening floating", which is simply referred to as "unidirectional fixed opening floating".

[0599] In Embodiment 2 of the present invention, |α1|, |α2|, |α3|, and |α4| are in the range of 0.01 to 0.5 degrees / second.

[0600] In Embodiment 2 of the present invention, the duration of each floating control step is in the range of 0.1 to 10 seconds.

[0601] Optionally, |α1|, |α2|, |α3|, and |α4| are in the range of 0.5 to 1 degree / second.

[0602] Optionally, the duration of each floating control step is in the range of 1 to 10 seconds.

[0603] Optionally, the distance threshold between the first roller 1 and / or the second roller 2 is in the range of 0 to 50 micrometers.

[0604] Optionally, the distance threshold between the first roller 1 and / or the second roller 2 is in the range of 50 to 500 micrometers.

[0605] Optionally, the distance threshold between the first roller 1 and / or the second roller 2 is in the range of 0.5 to 1 mm.

[0606] Optionally, the distance threshold between the first roller 1 and / or the second roller 2 is in the range of 1 to 200 mm.

[0607] Optionally, the fourth floating control step starts and ends simultaneously with the compensation control step; the threshold is set to the distance by which the current position of the second roller 2 deviates from the reference position in the reference direction from point O. 1-1 Distance to reference plane 8.

[0608] Optionally, the second and third floating control steps are combined into a single floating control step.

[0609] Optionally, the duration of each floating control step is in the range of 0.1 to 1 second.

[0610] Optionally, the duration of each compensation control step is in the range of 0.1 to 1 second.

[0611] Optionally, Ψ1∦Ψ0, and the absolute value of the angle between plane Ψ1 and plane Ψ0 is in the range of 0.1 to 5 degrees.

[0612] It should be noted that the symbol “∦” indicates that they are not parallel.

[0613] Optionally, in each floating control step, the average angular velocity of one of the two rollers rotating about the other roller is different. Example 3:

[0614] Embodiment 3 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figures 31 to 35 As shown.

[0615] During the preparation process, the following steps occur sequentially: the first floating control step, the first compensation control step, the second floating control step, and the second compensation control step.

[0616] In Embodiment 3 of the present invention, the steps of floating control and compensation control are similar to those in Embodiment 1. The same parts will not be repeated. The following only describes the differences.

[0617] The floating control step stops when the current position of the first roller 1 or the second roller 2 deviates from the reference position in the reference direction by a distance threshold greater than or equal to the distance threshold; the compensation control step is initiated when the current position of the first roller 1 or the second roller 2 deviates from the reference position in the reference direction by a distance threshold greater than or equal to the distance threshold.

[0618] In Embodiment 3 of the present invention, the reference plane 8 is set as the reference position.

[0619] In Embodiment 3 of the present invention, the "distance threshold" is converted into the "angle threshold"; the angle threshold is set to 1.5 degrees.

[0620] In Embodiment 3 of the present invention, during the preparation process, when no compensation control step occurs, the instantaneous angular velocities of the first roller 1 and the second roller 2 are θ′1 and θ′2, respectively, θ′1=-θ′2, and |θ′1|=|θ′2|.

[0621] It should be noted that when the compensation control step occurs, if the roller system rotates around the first roller shaft at an instantaneous angular velocity β′ t If the first roller 1 rotates, its instantaneous angular velocity of rotation is (θ′1+β′). tThe instantaneous rotational angular velocity of the second roller 2 is θ′2; if the roller system rotates around the second roller axis at β′ t The instantaneous angular velocity of the second roller 2 as it rotates is (θ′2+β′). t The instantaneous angular velocity of the first roller 1 is θ′1. In the compensation control step, with Nip point as the reference, the absolute value of the angular velocity and the linear velocity of the roller surface of the first roller 1 and the roller surface of the second roller 2 when passing through the roll gap 3 are equal. The compensation control step does not actively change the pressure in the molten pool 5; only the floating control step will actively change the pressure in the molten pool 5.

[0622] The initial position of the two rollers is Figure 31 The location shown; the placement plane is located at reference plane 8.

[0623] The steps for the first float control are as follows: Figures 31 to 32 As shown: t 1-1 To t 1-2 At time t, the instantaneous angular velocity and average angular velocity of the first roller 1 are α and α, respectively. t1 and α1, α t1 >0, the first roller 1 rotates counterclockwise around the second roller shaft by an angle ω1, the placement plane changes, α1=1 degree / second, ω1=1.5 degrees, t 1-2 -t 1-1 =|ω1| / |α1|=1.5 seconds; the direction of the effective velocity is always the same as the preparation direction.

[0624] The steps of the first compensation control, such as Figures 32 to 33 As shown: t 1-3 To t 1-4 At time t, the roller system begins to rotate clockwise around the second axis by an angle ϖ1 with an average angular velocity β1, the plane of placement changes, β1 = -1 degree / second, ϖ1 = -1.5 degrees, ϖ1 = -ω1, t 1-4 -t 1-3 =|ϖ1| / |β1|=1.5 seconds.

[0625] The first "change of the placement plane by the floating control step" completely offsets the first "change of the placement plane by the compensation control step".

[0626] The steps of the second float control are as follows: Figures 33 to 34 As shown: t 2-1 To t 2-2 At time t, the second roller 2 rotates counterclockwise around the first roller shaft by an angle ω2 with an average angular velocity α1, changing the plane of placement. α1 = 0.25 degrees / second, ω2 = 1.5 degrees. 2-2 -t 2-1 =|ω2| / |α2|=6 seconds; the direction of the effective velocity is always opposite to the preparation direction.

[0627] The steps of the second compensation control, such as Figures 34 to 35 As shown: t 2-3 To t 2-4 At time t, the roller system rotates clockwise around the first axis with an average angular velocity β2 by an angle ϖ2, changing the plane of placement. β2 = -1 degree / second, ϖ2 = -1.5 degrees, ϖ2 = -ω2; 2-4 -t 2-3 =|ϖ2| / |β2|=1.5 seconds.

[0628] The second "change of the placement plane by the floating control step" completely cancels out the second "change of the placement plane by the compensation control step".

[0629] The above-mentioned "first floating control step, first compensation control step, second floating control step and second compensation control step" constitute "a complete process"; during the preparation process, "a complete process" may occur only once, or "a complete process" may occur repeatedly until the preparation process ends or the preparation process is unexpectedly terminated.

[0630] It is understandable that "the preparation process is over" could be caused by the "process is over" or by a change in the composition of the prepared blank 7.

[0631] It is understandable that a person skilled in the art can directly and without doubt know that "the process is over"; "the process is over" can be determined by "the billet 7 is no longer removed from the molten pool 5"; "the process is over" can also be determined by "no more substances for preparing the billet 7 are added to the molten pool 5".

[0632] It is understandable that a person skilled in the art would directly and without doubt know that "the composition of the prepared billet 7 has been changed"; in one process, two or more billets 7 with different compositions can be prepared. For example, in one process, a billet 7 with silicon steel composition is prepared first. After the preparation of the silicon steel billet 7 is completed, the composition of the molten metal entering the molten pool 5 is changed to prepare a billet 7 with stainless steel composition, until the process is completed; "the billet 7 with silicon steel composition" and "the billet 7 with stainless steel composition" are billets 7 with different compositions.

[0633] It is understandable that the above-mentioned "one process" includes two "preparation processes"; one "preparation process" refers to "a process in which the composition of the billet 7 does not change"; in the above-mentioned "one process", the preparation of "the billet 7 with silicon steel composition" and "the billet 7 with stainless steel composition" were completed successively, which is considered as two preparation processes; that is to say, at least one "preparation process" occurs in the "one process".

[0634] It is understandable that "two or more blanks 7 with different compositions can be prepared in one process" is to avoid the cost of replacing the flow distribution device 6 and / or the side sealing device, and to improve equipment utilization so as to reduce production costs as much as possible.

[0635] Optionally, the above-mentioned "first floating control step and first compensation control step" can be considered as a complete process, and the above-mentioned "second floating control step and second compensation control step" can be considered as a complete process. The two complete processes can be combined as needed until the preparation process ends or the preparation process is unexpectedly terminated.

[0636] The benefits of Embodiment 3 of the present invention are: it can reduce the requirements for the machining accuracy of the roller body; the current machining accuracy of the roller body has reached the micron level in order to meet the synchronization (or consistency) of the transmission behavior along the roller body axis as much as possible, and the technical solution involved in Embodiment 3 of the present invention is expected to significantly reduce the manufacturing and / or maintenance costs of the core components.

[0637] In the floating control step, the maximum absolute value of the instantaneous angular velocity of the placement plane rotation (or, one roller rotating relative to another roller) is in the range of 0.01 to 100 degrees / second.

[0638] Optionally, the first compensation control step is initiated within 0.5 to 10 seconds after the first float control step ends.

[0639] Optionally, in the floating control step, the absolute value of the instantaneous angular velocity of the placement plane rotation (or, one roller rotation relative to another roller) is in the range of 0.01 to 0.1 degrees per second.

[0640] Optionally, the angle threshold is in the range of 0.01 to 10 degrees.

[0641] Optionally, in the floating control step, the absolute value of the average angular velocity of the rotation of the placement plane (or, the rotation of one roller relative to another roller) is in the range of 0.001 to 0.1 degrees per second.

[0642] Optionally, in the floating control step, a single relative movement between the two rollers causes the absolute value of a single displacement of the moving roller to be in the range of 5 to 500 micrometers.

[0643] Optionally, in the compensation control step, the roller system rotates by a certain angle about any axis parallel to the roller shaft.

[0644] Optionally, the steps of compensation control are a combination of translation and / or rotation, and the combination can be arbitrary and complex; however, the actual situation should be taken into account, and the simplest roller system motion mode should be used as much as possible; if necessary, only translation or only rotation should be used to reduce equipment construction costs and / or production costs, and to ensure that the process has the necessary robustness.

[0645] It is understandable that, depending on the actual process, the steps of compensation control and floating control can be combined as needed; that is, the "distance threshold" and / or "preset position" are subject to change, and this change is made at any time according to the actual process; the "change of the placement plane by the floating control steps" and the "change of the placement plane by the compensation control steps" are partially or completely canceled out. Example 4:

[0646] Embodiment 4 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figures 36 to 40 As shown.

[0647] In Embodiment 4 of the present invention, during the preparation process, multiple relative movements are controlled between the two rollers; each relative movement between the two rollers causes the placement plane to rotate once; during each first rotation, the inner product of the floating speed (or, the first speed) and the preparation speed is always less than zero, the direction of the effective speed is always opposite to the preparation direction, and the first inner product is always less than zero.

[0648] In Embodiment 4 of the present invention, during the preparation process, the relative motion between the two rollers is controlled to cause the placement plane to rotate a second time. During the second rotation, the inner product of the floating speed (or the second speed) and the preparation speed is always greater than zero, the direction of the effective speed is always the same as the preparation direction, and the second inner product is always greater than zero.

[0649] In Embodiment 4 of the present invention, the product of the first inner product and the second inner product is less than zero.

[0650] like Figures 36 to 37 As shown: The relative motion between the two rollers causes the placement plane to undergo a first rotation; the first roller 1 rotates clockwise around the second roller shaft by a certain angle, and the motion of the first roller shaft produces a displacement O1→O. 1-1 During the first rotation, the inner product of the floating velocity (or the first velocity) and the preparation velocity is always less than zero, and the direction of the effective velocity is always opposite to the preparation direction.

[0651] like Figures 37 to 38 As shown: The relative motion between the two rollers causes the placement plane to rotate once; the second roller 2 rotates counterclockwise around the first roller axis by a certain angle, and the motion of the second roller axis produces a displacement O2→O. 2-1During the first rotation, the inner product of the floating velocity (or the first velocity) and the preparation velocity is always less than zero, and the direction of the effective velocity is always opposite to the preparation direction.

[0652] like Figures 38 to 39 As shown: The relative motion between the two rollers causes the placement plane to undergo a second rotation; the second roller 2 rotates clockwise around the first roller shaft by a certain angle, and the motion of the second roller shaft produces a displacement O. 2-1 →O 2-2 During this second rotation, the inner product of the floating velocity (or the second velocity) and the preparation velocity is always greater than zero, and the direction of the effective velocity is always the same as the preparation direction.

[0653] like Figures 39 to 40 As shown: the relative motion between the two rollers causes the placement plane to rotate once; the second roller 2 rotates counterclockwise around the first roller axis by a certain angle, and the motion of the second roller axis produces a displacement O. 2-2 →O 2-3 During the first rotation, the inner product of the floating velocity (or the first velocity) and the preparation velocity is always less than zero, and the direction of the effective velocity is always opposite to the preparation direction.

[0654] The preparation process involves four relative movements between the two rollers, resulting in: three first rotations and one second rotation; among which, the multiple first rotations occur in a partially continuous manner.

[0655] During a single relative motion between the two rollers, the maximum absolute value of the floating speed ranges from 0.2 to 6 micrometers per second.

[0656] Optionally, the maximum absolute value of the floating speed is in the range of 0.1 to 100 micrometers per second.

[0657] Optionally, the maximum absolute value of the floating speed is in the range of 0.1 to 9 mm / s. Example 5:

[0658] Embodiment 5 of this invention discloses a method for controlling the roll gap in a twin-roll thin strip process, such as... Figures 41 to 43 As shown.

[0659] In embodiment 5 of the present invention, as Figures 41 to 42 As shown, during the relative motion of the two rollers, the direction of the velocity of the first roller 1 and the second roller 2 is perpendicular to the reference plane 8. Specifically, the motion path of the first roller shaft is O1~O 1-1 ~O 1-2 ~O 1-3 ~O 1-4 The movement path of the second roller is O2~O 2-1 ~O 2-2 ~O2-3 ~O 2-4 The movement of the two rollers can be simultaneous, alternating, or partially overlapping; the absolute value of the displacement of the first roller 1 and / or the second roller 2 relative to the ground each time is in the range of 5 to 500 micrometers; the Nip point is always located on the reference line.

[0660] In Embodiment 5 of the present invention, the opening of the roll gap 3 changes throughout the entire process of relative motion between the two rolls.

[0661] In embodiment 5 of the present invention, as Figure 42 and 43 As shown, during the preparation of the blank 7, when the two rollers move alternately, the floating mode of the roller gap 3 can be set as follows:

[0662] In the first relative motion between the two rollers, the second roller 2 is stationary relative to the ground, while the first roller 1 undergoes a relative motion with the ground. The motion of the first roller shaft produces a displacement O1→O. 1-1 When the plane of placement undergoes its first rotation, point Nip shifts from N0 to N. 1-1 The direction of the effective velocity is always opposite to the direction of preparation;

[0663] In the second relative motion between the two rollers, the first roller 1 is stationary relative to the ground, while the second roller 2 undergoes a relative motion with the ground. The motion of the second roller shaft produces a displacement O2→O. 2-1 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 1-1 →N 2-1 The direction of the effective velocity is always opposite to the direction of preparation;

[0664] In the third relative motion between the two rollers, the second roller 2 is stationary relative to the ground, while the first roller 1 undergoes a relative motion with the ground. The motion of the first roller shaft produces a displacement O. 1-1 →O 1-2 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 2-1 →N 1-2 The direction of the effective velocity is always opposite to the direction of preparation;

[0665] In the fourth relative motion between the two rollers, the first roller 1 is stationary relative to the ground, while the second roller 2 undergoes a relative motion with the ground. The motion of the second roller shaft produces a displacement O. 2-1 →O 2-2 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 1-2 →N 2-2 The direction of the effective velocity is always opposite to the direction of preparation;

[0666] In the fifth relative motion between the two rollers, the second roller 2 is stationary relative to the ground, while the first roller 1 undergoes a relative motion with the ground. The motion of the first roller shaft produces a displacement O. 1-2 →O 1-3 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 2-2 →N 1-3 The direction of the effective velocity is always opposite to the direction of preparation;

[0667] In the sixth relative motion between the two rollers, the first roller 1 is stationary relative to the ground, while the second roller 2 undergoes a relative motion with the ground. The motion of the second roller shaft produces a displacement O. 2-2 →O 2-3 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 1-3 →N 2-3 The direction of the effective velocity is always opposite to the direction of preparation;

[0668] In the seventh relative motion between the two rollers, the second roller 2 is stationary relative to the ground, while the first roller 1 undergoes a relative motion with the ground. The motion of the first roller shaft produces a displacement O. 1-3 →O 1-4 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 2-3 →N 1-4 The direction of the effective velocity is always opposite to the direction of preparation;

[0669] In the eighth relative motion between the two rollers, the first roller 1 is stationary relative to the ground, while the second roller 2 undergoes a relative motion with the ground. The motion of the second roller shaft produces a displacement O. 2-3 →O 2-4 When the plane of placement undergoes its first rotation, point Nip is displaced by N. 1-4 →N 2-4 The direction of the effective velocity is always opposite to the direction of preparation;

[0670] Continue repeating the alternating motion between the two rollers as described above until the preparation process ends or the process is unexpectedly terminated.

[0671] The statement "The direction of the effective velocity is always opposite to the preparation direction" can also be expressed as "The inner product of the effective velocity and the preparation velocity is always less than zero"; or "The inner product of the floating velocity and the preparation velocity is always less than zero".

[0672] like Figure 43 As shown, the multiple first rotations occur continuously; there is no relative movement between the two rollers between two adjacent first rotations; only the first rotation occurs throughout the entire preparation process.

[0673] After the preparation process is completed or before the next preparation process begins, adjust the two rollers to... Figure 41 The location shown, or a more suitable location.

[0674] Optionally, in Embodiment 5 of the present invention, the absolute value of the displacement of the first roller 1 and / or the second roller 2 in each movement is in the range of 20 to 200 micrometers.

[0675] Optionally, the direction of movement (speed) of the first roller 1 and / or the direction of movement (speed) of the second roller 2 both point towards the direction of the long-range shear-thinning interface 4 in the molten pool 5.

[0676] The method shown in Embodiment 5 of this invention can be used for the small-batch preparation of various high-end materials, and can also be used for the design of process parameters and / or the composition of the preform 7 in the laboratory.

[0677] Optionally, during the relative motion between the two rollers, the change in the opening of the roll gap 3 is in the range of 0.2 to 50 micrometers.

[0678] Optionally, in other embodiments, the angle between the direction of the velocity of the first roller 1 and / or the second roller 2 and the reference direction is λ. During the partial or complete time of relative motion between the two rollers, λ = 135 degrees, or 120 degrees < λ < 180 degrees.

[0679] Optionally, during the first rotation, the maximum absolute value of the floating speed ranges from 0.1 to 9000 micrometers per second.

[0680] Optionally, the frequency of the first rotation is in the range of 0.01 to 10 Hz.

[0681] Understandably, since the composition of the available blank 7 is very wide, the range of selectable "maximum absolute value of the floating speed" and / or "frequency of occurrence of the first rotation" is huge; those skilled in the art can directly and without doubt know that it should be selected from "0.1 to 9000 micrometers / second" and / or "0.01 to 10 Hz" depending on the composition of the specific blank 7. Example 6:

[0682] Embodiment 6 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figures 44 to 48 As shown.

[0683] During the preparation of the blank 7: multiple relative movements are controlled between the two rollers to allow multiple first rotations; during each first rotation, the direction of the effective velocity is always the same as the preparation direction.

[0684] like Figure 44As shown at time t1, at the beginning of the first floating of the roll gap 3, the two rolls are in their initial positions, and the placement plane is located at plane Ψ0, which coincides with the reference plane 8.

[0685] like Figure 45 The figure shows the positions of the two rollers at time t2, at the end of the first roll gap 3 floating and at the beginning of the second roll gap 3 floating.

[0686] like Figure 46 The figure shows the positions of the two rollers at time t3, at the end of the second roll gap 3 floating and at the beginning of the third roll gap 3 floating, with the placement plane located at plane Ψ1.

[0687] like Figure 47 The figure shows the positions of the two rollers at time t4, at the end of the third roll gap 3 float and at the beginning of the fourth roll gap 3 float.

[0688] like Figure 48 The figure shows that at time t5, at the end of the fourth roll gap 3 floating, the placement plane is located at plane Ψ2.

[0689] The first relative movement between the two rollers lasts for 0.5 seconds, resulting in the first floating of the roll gap 3, as shown. Figures 44 to 45 As shown: the direction of the effective velocity is the same as the preparation direction, and the placement plane produces a first rotation; during the first rotation, the direction of the effective velocity remains the same as the preparation direction; the second roller 2 is a moving roller, and the second roller 2 rotates clockwise around the first roller axis with an average angular velocity α1 by an angle ω. 1-1 ω 1-1 = -0.5 degrees, α1 = -1 degree / second; the opening of the roll gap 3 is constant, that is, during the first rotation, the rotation radius of the second roll 2 around the first roll axis remains unchanged.

[0690] The second relative motion between the two rollers lasts for 0.5 seconds, resulting in a second floating of the roll gap 3, as shown. Figures 45 to 46 As shown: the placement plane generates a first rotation; during the first rotation, the direction of the effective velocity is always the same as the preparation direction; the first roller 1 is a moving roller, and the first roller 1 rotates counterclockwise around the second roller axis by an angle ω with an average angular velocity α2. 2-1 ω 2-1 =0.5 degrees, α2=1 degree / second. After the second floating process of roll gap 3 is completed, the placement plane is located at plane Ψ1, Ψ1∥Ψ0; the opening of roll gap 3 is constant.

[0691] The third relative motion between the two rollers lasts for 0.5 seconds, resulting in a third floating of the roll gap 3, as shown. Figures 46 to 47As shown: the direction of the effective velocity is always the same as the preparation direction, and the placement plane produces one first rotation; the first roller 1 is a moving roller, and the first roller 1 rotates counterclockwise around the second roller axis with an average angular velocity α3 by an angle ω. 2-2 ω 2-1 =0.5 degrees, α3=1 degree / second; the opening of roll gap 3 is constant.

[0692] The fourth relative movement between the two rollers lasts for 0.5 seconds, resulting in the fourth floating of the roll gap 3, as shown. Figures 47 to 48 As shown: the direction of the effective velocity is the same as the preparation direction, and the placement plane produces a first rotation; the second roller 2 is a moving roller, and the second roller 2 rotates clockwise around the first roller axis with an average angular velocity α4 by an angle ω. 1-2 ω 1-2 = -0.5 degrees, α1 = -1 degree / second; the opening of roll gap 3 is constant.

[0693] After the fourth relative motion between the two rollers, the placement plane is located at plane Ψ2, Ψ2∥Ψ0, on plane Ω, quadrilateral O 1-2 O 2-2 O2O1 is a rectangle, O 1-2 O1⊥O1O2,O 2-2 O1⊥O1O2.

[0694] The relative motion between the two rollers from the first to the fourth time results in the absolute value of the displacement vector D1 of the first roller 1 being the line segment O1O. 1-2 The length, and the direction from point O1 to point O. 1-2 At point O2O, the absolute value of the displacement vector D2 of the second roller 2 is the line segment O2O. 2-2 The length, and the direction from point O2 to point O. 2-2 Location; D1=D2.

[0695] The displacement of the Nip point generated by the four relative movements between the two rollers is not equal to zero in the reference direction, and the direction of the displacement in the reference direction is the same. During the four first rotations, the direction of the effective speed is always the same as the preparation direction, and the roller gap 3 floats in a single direction.

[0696] Optionally, after the fourth relative movement between the two rollers, the relative movement between the two rollers can be continuously generated once or more from the first to the fourth time to continuously generate the first rotation until the preparation process ends or the preparation process is unexpectedly terminated.

[0697] During each roll gap 3 floating process, the absolute value of the displacement of the Nip point caused by the relative movement between the two rolls is in the range of 5 to 100 micrometers.

[0698] Optionally, during each roll gap 3 floating process, the absolute value of a single displacement of the Nip point caused by the relative movement between the two rolls is in the range of 100 to 500 micrometers.

[0699] Optionally, during a relative motion between the two rollers, one roller moves relative to the ground while the other roller remains stationary relative to the ground, and the trajectory of the moving roller is a continuous arc or curve; during the portion of time during which the relative motion occurs between the two rollers, the moving roller rotates around the stationary roller; that is, during the portion of time during a relative motion between the two rollers, the opening of the roller gap 3 is constant. Example 7:

[0700] Embodiment 7 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figure 49 As shown.

[0701] like Figure 49 As shown, point N is the Nip point in its natural state; "Arc 1" and "Arc 2" are both arcs centered at point O2; point N1 is located on line segment O. 1-1 On O2, line segment O 1-1 O2 lies on plane Ψ1; point N2 lies on line segment O 1-2 On O2, line segment O 1-2 O2 lies on plane Ψ2; point N3 lies on line segment O. 1-3 On O2, line segment O 1-3 O2 lies on plane Ψ3; line segment O 1-1 O 1-2 The lines containing the line segment N1N2 and the line containing the line segment N1N2 are both perpendicular to the reference line; O1O 1-1 ⊥O 1-1 O 1-2 O 1-1 O 1-2 ⊥O 1-2 O 1-3 ,NN1⊥N1N2,N1N2⊥N2N3.

[0702] Point O 1-3 The distance to the reference plane 8 is 1.5 mm.

[0703] like Figure 49 As shown, points O1 and O 1-3 All are located on "arc one";

[0704] like Figure 49 As shown, points N and N3 are both located on "arc two".

[0705] like Figure 49As shown, during a certain period of the preparation process, the relative motion between the two rollers causes the placement plane to rotate multiple times; during the relative motion between the two rollers, the first roller 1 moves relative to the ground, while the second roller 2 remains stationary relative to the ground.

[0706] like Figure 49 As shown, from time t0 to t1, the steps of the first floating control are as follows: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground; during the movement of the first roller 1, the velocity of the first roller 1 is not equal to zero, and the direction of the velocity of the first roller 1 does not change, so as to allow the first roller shaft to start from point O1 and move along line segment O1O 1-1 Uninterrupted motion to point O 1-1 Stop after point O; at point O1 and point O 1-1 At the beginning and end of the first floating control step, the speed of the first roller 1 is zero, and the floating speed is zero. Nip point starts from point N and moves continuously along line segment NN1 to point N1 and then stops. A first rotation occurs, and the placement plane moves from plane Ψ0 to plane Ψ1. Nip point undergoes a displacement N→N1. The direction of displacement N→N1 is opposite to the reference direction. During this first rotation, the direction of the floating speed is always opposite to the reference direction (or, the angle between the direction of the floating speed and the reference direction is always 180 degrees), and the direction of the effective speed is always opposite to the preparation direction.

[0707] like Figure 49 As shown, the steps of the second floating control occurring between times t2 and t3 are as follows: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground; during the movement of the first roller 1, the velocity of the first roller 1 is not equal to zero, and the direction of the velocity of the first roller 1 does not change, so as to allow the first roller shaft to move from point O. 1-1 Starting from point O, along line segment O 1-1 O 1-2 Uninterrupted motion to point O 1-2 Stop at point O; 1-1 Location and point O 1-2 At the beginning and end of the second floating control step, the speed of the first roller 1 is zero, and the floating speed is zero. Nip point starts from point N1 and moves continuously along line segment N1N2 to point N2 and then stops. A first rotation occurs, and the placement plane moves from plane Ψ1 to plane Ψ2. Nip point undergoes a displacement N1→N2. The direction of N1→N2 is perpendicular to the reference direction. During this first rotation, the direction of the floating speed is always perpendicular to the reference direction (or, the angle between the direction of the floating speed and the reference direction is always 90 degrees), and the direction of the effective speed is always opposite to the preparation direction.

[0708] like Figure 49 As shown, from time t4 to t5, the steps of the third floating control are as follows: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground; during the movement of the first roller 1, the velocity of the first roller 1 is not equal to zero, and the direction of the velocity of the first roller 1 does not change, so as to allow the first roller shaft to move from point O. 1-2 Starting from point O, along line segment O 1-2 O 1-3 Uninterrupted motion to point O 1-3 Stop at point O; 1-2 Location and point O 1-3 At the beginning and end of the third floating control step, the speed of the first roller 1 is zero, and the floating speed is zero. Nip point starts from point N2 and moves continuously along line segment N2N3 to point N3 and then stops. A first rotation occurs, and the placement plane moves from plane Ψ2 to plane Ψ3. Nip point undergoes a displacement N2→N3. The direction of displacement N2→N3 is opposite to the reference direction. During this first rotation, the direction of the floating speed is always opposite to the reference direction, and the direction of the effective speed is always opposite to the preparation direction.

[0709] In Embodiment 7 of the present invention, the preset position and the reference position of the first roller 1 are both set on the reference plane 8; the distance threshold is set to 1.5 mm.

[0710] like Figure 49 As shown, from time t6 to t7, a compensation control step occurs. The two rollers are relatively stationary, and the control roller system rotates counterclockwise around the second roller shaft to allow the first roller shaft to rotate from point O. 1-3 Starting from point O1, the first roller 1 moves continuously along the "arc one" until it stops at point O1; at time t7, the first roller 1 reaches the preset position.

[0711] like Figure 49 As shown, the three floating control steps and the one compensation control step constitute "one complete process"; the three "changes to the placement plane caused by the floating control steps" and the one "changes to the placement plane caused by the compensation control steps" completely cancel each other out; during the entire preparation process, "one complete process" can occur only once, or "one complete process" can occur repeatedly.

[0712] In Embodiment 7 of the present invention, the first rotation occurs continuously; during the preparation process, only the first rotation occurs; during one first rotation, the direction of the floating velocity does not change.

[0713] In Embodiment 7 of the present invention, two first rotations occur consecutively between times t0 and t3; during the first rotation between times t0 and t1, the angle between the direction of the floating velocity and the reference direction does not change (or, the angle between the direction of the floating velocity and the reference direction is equal to 180 degrees); during the first rotation between times t2 and t3, the angle between the direction of the floating velocity and the reference direction does not change (or, the angle between the direction of the floating velocity and the reference direction is equal to 90 degrees); the direction of the floating velocity in the first rotation is perpendicular to the direction of the floating velocity in the second rotation.

[0714] In Embodiment 7 of the present invention, two first rotations occur consecutively between times t2 and t5; during the first rotation occurring between times t2 and t3, the angle between the direction of the floating velocity and the reference direction does not change (or, the angle between the direction of the floating velocity and the reference direction is equal to 90 degrees); during the first rotation occurring between times t4 and t5, the angle between the direction of the floating velocity and the reference direction does not change (or, the angle between the direction of the floating velocity and the reference direction is equal to 180 degrees); the direction of the floating velocity in the first rotation is perpendicular to the direction of the floating velocity in the second rotation.

[0715] In Embodiment 7 of the present invention, during a certain period of the preparation process: during the first rotation, the direction of the floating speed does not change; during the second rotation, the direction of the floating speed does not change; during the third rotation, the direction of the floating speed does not change. Example 8:

[0716] Embodiment 8 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figure 50 As shown.

[0717] like Figure 50 As shown, point N is the Nip point in its natural state; "Arc 1" and "Arc 2" are both arcs centered at point O2; points N1, N2, and O 1-1 All are located on line segment O 1-2 On O2, line segment O 1-2 O2 lies on plane Ψ1; points N3, N4, and O 1-3 All are located on line segment O 1-4 On O2, line segment O 1-4 O2 lies on plane Ψ2; line segment O 1-2 O2 and line segment O 1-4 O2 all intersects the reference line obliquely.

[0718] The reference plane 8 is set as the reference position; the preset position of the first roller 1 is set on the reference plane 8; the distance threshold is set to 0.5 mm, that is, when the distance of the first roller 1 from the reference position in the reference direction is greater than or equal to 0.5 mm, the compensation control step can be started at any time.

[0719] like Figure 50 As shown, point O 1-4 The distance to the reference position is 0.5 mm.

[0720] like Figure 50 As shown, during the preparation process, the relative motion between the two rollers causes the placement plane to undergo multiple first rotations.

[0721] like Figure 50 As shown, from time t0 to t1, the steps of the first floating control are as follows: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground; and during the movement of the first roller 1, the direction of the velocity of the first roller 1 does not change, so that the first roller shaft can start from point O1 and move along line segment O1O 1-1 Uninterrupted motion to point O 1-1 Stop after point O; at point O1 and point O 1-1 At the beginning and end of this floating control step, the speed of the first roller 1 is zero and the floating speed is zero. Starting from point N, point Nip moves continuously along line segment NN1 to point N1 and then stops, and the placement plane undergoes a first rotation. The placement plane moves from plane Ψ0 to plane Ψ1, and point Nip is displaced N→N1. During this first rotation, the direction of the effective speed is always opposite to the preparation direction.

[0722] like Figure 50 As shown, from time t2 to t3, relative motion occurs between the two rollers: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground to allow the first roller shaft to move from point O. 1-1 Starting from point O, along line segment O 1-1 O 1-2 Movement to point O 1-2 Then stop; at point O 1-1 and point O 1-2At the beginning and end of the relative motion between the two rollers, the velocity of the first roller 1 is zero, and the floating velocity is zero. Nip point starts from point N1 and moves continuously along line segment N1N2 to point N2 before stopping. The placement plane does not move, and Nip point undergoes a displacement N1→N2. During the displacement N1→N2, the direction of the velocity of the first roller 1 is always perpendicular to the roller surface of the second roller 2. This makes the direction of the floating velocity perpendicular to the roller surfaces of the first roller 1 and / or the second roller 2, and the effective velocity is zero. In other words, during the displacement N1→N2, the direction of the floating velocity is oblique to the reference plane 8, and the opening of the roller gap 3 changes. However, the inner product of the floating velocity and the preparation velocity is always zero, and the placement plane does not change.

[0723] like Figure 50 As shown, from time t4 to t5, the steps of the second floating control are as follows: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground; and during the movement of the first roller 1, the direction of the velocity of the first roller 1 does not change, so as to allow the first roller shaft to move from point O. 1-2 Starting from point O, along line segment O 1-2 O 1-3 Uninterrupted motion to point O 1-3 Stop at point O; 1-2 Location and point O 1-3 At the beginning and end of this floating control step, the speed of the first roller 1 is zero, and the floating speed is zero. Starting from point N2, the Nip point moves continuously along line segment N2N3 to point N3 and then stops, and the placement plane undergoes a first rotation. The placement plane moves from plane Ψ1 to plane Ψ2, and the Nip point undergoes a displacement N2→N3. During this first rotation, the direction of the effective speed is always opposite to the preparation direction.

[0724] like Figure 50 As shown, from time t6 to t7, relative motion occurs between the two rollers: the second roller 2 is stationary relative to the ground; the first roller 1 is controlled to move relative to the ground to allow the first roller shaft to move from point O. 1-3 Starting from point O, along line segment O 1-3 O 1-4 Uninterrupted motion to point O 1-4 Stop at point O; 1-3 Location and point O 1-4At the beginning and end of the relative motion between the two rollers, the velocity of the first roller 1 is zero. Nip point starts from point N3 and moves continuously along line segment N3N4 to point N4 before stopping. Nip point undergoes a displacement N3→N4. The placement plane does not move. During the displacement N3→N4, the direction of the velocity of the first roller 1 is perpendicular to the roller surface of the second roller 2. This makes the direction of the floating velocity perpendicular to the roller surface of the first roller 1 and / or the second roller 2, and the effective velocity is zero. In other words, during the displacement N3→N4, the direction of the floating velocity is oblique to the reference plane 8, and the opening of the roller gap 3 changes. However, the inner product of the floating velocity and the preparation velocity is always zero, and the placement plane does not change.

[0725] like Figure 50 As shown, from time t8 to t9, a compensation control step occurs, during which the two rollers remain relatively stationary, and the control roller system rotates counterclockwise around the second roller shaft to allow the first roller shaft to rotate from point O. 1-4 Starting from point O1, the first roller 1 moves along the "arc one" to point O1 and then stops; at time t9, the first roller 1 reaches the preset position.

[0726] like Figure 50 As shown, the steps of four relative movements between the two rollers and one compensation control constitute "one complete process"; during the entire preparation process, "one complete process" may occur only once or may be repeated.

[0727] like Figure 50 As shown, in "a complete process", the relative motion between the two rollers in all four instances causes the roller gap 3 to float. However, the relative motion between the two rollers in the second and fourth instances does not change the placement plane. In "a complete process", the relative motion between the two rollers in the second and fourth instances is used to adjust the opening of the roller gap 3 to reduce the changes in the opening of the roller gap 3 caused by various errors, and to ensure that the billet 7 has a uniform thickness. In "a complete process", the relative motion between the two rollers in the second instance does not produce the first rotation, and the relative motion between the two rollers in the fourth instance does not produce the first rotation.

[0728] In embodiment 8 of the present invention, as Figure 50 As shown, in “a complete process”, the two first rotations occur consecutively. Example 9:

[0729] Embodiment 9 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figure 51 As shown.

[0730] like Figure 51 As shown, vectors O1→O2 and O1→O1-2 The angle formed is θ; θ ∈ (90 degrees, 180 degrees); point O 1-1 Located on line segment O1O 1-2 Above; point N is the Nip point in its natural state; point N1 lies on line segment NN2; point N1 lies on line segment O2O 1-1 Above, line segment O2O 1-1 Point N2 is located on plane Ψ1; point N2 is located on line segment O2O. 1-2 Above, line segment O2O 1-2 Located on plane Ψ2; O1O 1-2 ∥NN2.

[0731] like Figure 51 As shown, during a certain period of the preparation process, the relative motion between the two rollers causes the placement plane to rotate multiple times; during the relative motion between the two rollers, the first roller 1 moves relative to the ground, while the second roller 2 remains stationary relative to the ground.

[0732] like Figure 51 As shown, from time t0 to t1, the placement plane undergoes its first rotation: the second roller 2 remains stationary relative to the ground; a relative motion is controlled between the first roller 1 and the ground; and during the movement of the first roller 1, the direction of its velocity does not change, allowing the first roller shaft to start from point O1 and move along line segment O1O. 1-1 Uninterrupted motion to point O 1-1 Stop after point O; at point O1 and point O 1-1 At the beginning and end of this first rotation, the speed of the first roller 1 is zero; point Nip starts from point N and moves continuously along line segment NN1 to point N1 and then stops; the placement plane moves from plane Ψ0 to plane Ψ1; during this first rotation, the inner product of the effective speed and the preparation speed is always less than zero, and the direction of the effective speed is always opposite to the preparation direction; this first rotation causes the placement plane to rotate by an angle ω1; the absolute value of ω1 is in the range of 0.1 to 1 degree.

[0733] like Figure 51 As shown, from time t2 to t3, the placement plane undergoes a second first rotation: the second roller 2 remains stationary relative to the ground; a relative motion is controlled between the first roller 1 and the ground; and during the movement of the first roller 1, the direction of its velocity does not change, allowing the first roller shaft to move from point O. 1-1 Starting from point O, along line segment O 1-1 O 1-2 Uninterrupted motion to point O 1-2 Stop at point O; 1-1 Location and point O 1-2At the beginning and end of this first rotation, the speed of the first roller 1 is zero; point Nip starts from point N1 and moves continuously along line segment N1N2 to point N2 and then stops; the placement plane moves from plane Ψ1 to plane Ψ2; during this first rotation, the inner product of the effective speed and the preparation speed is always less than zero, and the direction of the effective speed is always opposite to the preparation direction; this first rotation causes the placement plane to rotate by an angle of ω2; the absolute value of ω2 is in the range of 0.1 to 1 degree.

[0734] The first rotation and the second rotation occur consecutively; the frequency of the first rotation is in the range of 0.1 to 10 Hz.

[0735] The direction of the displacement N→N1 of the Nip point corresponding to the first rotation in the first rotation is the same as the direction of the displacement N1→N2 of the Nip point corresponding to the second rotation in the first rotation.

[0736] In Embodiment 9 of the present invention, the direction of the floating velocity is the same during the two first rotations.

[0737] It should be noted that in Embodiment 9 of the present invention, θ∈(90 degrees, 180 degrees) is more conducive to preventing excessive gas from entering the molten pool 5 from the meniscus. According to the simulation study of the inventors, this can significantly improve the surface quality of the billet 7. Example 10:

[0738] Embodiment 10 of the present invention discloses a method for controlling the roll gap in a two-roll thin strip process, such as... Figure 52 As shown.

[0739] like Figure 52 As shown, "Arc 1" is an arc with point O2 as its center; points O1 and O2 are also mentioned. 1-1 Point O 1-2 and point O 1-3 All points are located on "Arc One"; "Arc Two" is an arc centered at point O2; points N, N1, N2, and N3 are all located on "Arc Two"; point N is the Nip point in its natural state; point N1 is located on line segment O. 1-1 On O2, line segment O 1-1 O2 lies on plane Ψ1; point N2 lies on line segment O 1- On 2O2, line segment O 1-2 O2 lies on plane Ψ2; point N3 lies on line segment O. 1-3 On O2, line segment O 1-3 O2 is located on plane Ψ3.

[0740] like Figure 52As shown, during a certain period of the preparation process, the relative movement between the two rollers causes the placement plane to rotate multiple times; during the relative movement between the two rollers, the first roller 1 moves relative to the ground, while the second roller 2 remains stationary relative to the ground.

[0741] like Figure 52 As shown, from time t0 to t1, the placement plane undergoes its first rotation: the second roller 2 remains stationary relative to the ground; a relative motion occurs between the first roller 1 and the ground; and during the movement of the first roller 1, the opening of the roller gap 3 remains constant, allowing the first roller shaft to move continuously from point O1 along the "arc" to point O. 1-1 Stop after point O; at point O1 and point O 1-1 At the beginning and end of this first rotation, the speed of the first roller 1 and the floating speed of the Nip point are both zero. The Nip point starts from point N and moves continuously along "arc two" to point N1 and then stops. The placement plane moves from plane Ψ0 to plane Ψ1. During this first rotation, the inner product of the floating speed and the preparation speed is always less than zero, and the direction of the effective speed is always opposite to the preparation direction. This first rotation causes the placement plane to rotate by an angle of ω1. The absolute value of ω1 is in the range of 0.01 to 0.5 degrees.

[0742] like Figure 52 As shown, from time t2 to t3, the placement plane undergoes a second first rotation: the second roller 2 remains stationary relative to the ground; a relative motion occurs between the first roller 1 and the ground; and during the movement of the first roller 1, the opening of the roller gap 3 remains constant to allow the first roller shaft to move from point O. 1-1 Starting from point O, move continuously along the "arc one" to point O. 1-2 Stop at point O; 1-1 Location and point O 1-2 At the beginning and end of this first rotation, the speed of the first roller 1 and the floating speed of the Nip point are both zero. The Nip point starts from point N1 and moves continuously along "arc two" to point N2 before stopping. The placement plane moves from plane Ψ1 to plane Ψ2. During this second rotation, the inner product of the floating speed and the preparation speed is always less than zero, and the direction of the effective speed is always opposite to the preparation direction. This first rotation causes the placement plane to rotate by an angle of ω2. The absolute value of ω2 is in the range of 0.5 to 1 degree.

[0743] like Figure 52 As shown, from time t4 to t5, the placement plane undergoes its third first rotation: the second roller 2 remains stationary relative to the ground; a relative motion occurs between the first roller 1 and the ground; and during the movement of the first roller 1, the opening of the roller gap 3 remains constant to allow the first roller shaft to move from point O. 1-2Starting from point O, move continuously along the "arc one" to point O. 1-3 Stop at point O; 1-2 Location and point O 1-3 At the beginning and end of this first rotation, the speed of the first roller 1 and the floating speed of the Nip point are both zero. The Nip point starts from point N2 and moves continuously along "arc two" to point N3 before stopping. The placement plane moves from plane Ψ2 to plane Ψ3. During this first rotation, the inner product of the floating speed and the preparation speed is always less than zero, and the direction of the effective speed is always opposite to the preparation direction. This first rotation causes the placement plane to rotate by an angle of ω3. The absolute value of ω3 is in the range of 1 to 5 degrees.

[0744] The first rotation, the second rotation, and the third rotation occur consecutively; during the three rotations, the opening of the roll gap 3 remains unchanged.

[0745] The frequency of the first rotation is in the range of 0.1 to 5 Hz. Example 11:

[0746] Embodiment 11 of this invention discloses a schematic diagram of a partial structure of a twin-roll thin strip casting machine device for a roll gap control method applied to twin-roll thin strip processing, as shown below. Figures 53 to 57 As shown.

[0747] like Figure 53 As shown, the twin-roll thin strip casting machine includes a first roll body 1, a second roll body 2, a first main shaft 10, a second main shaft 11, a first bearing seat 12, a second bearing seat 13, a first inner track 14, a first outer track 15, a second outer track 16, and a second inner track 17; the first roll body 1 and the second roll body 2 are arranged opposite to each other; the minimum distance between the first roll body 1 and the second roll body 2 is called the roll gap 3; the first main shaft 10 of the first roll body 1 is placed in the first bearing seat 12; the second main shaft 11 of the second roll body 2 is placed in the second bearing seat 13; the first bearing seat 12 is movably arranged on the first inner track 14, and the second bearing seat 13 is movably arranged on the second inner track 17; the first inner track 14 is movably arranged on the first outer track 15; and the second inner track 17 is movably arranged on the second outer track 16.

[0748] It is understandable that "track" refers to a device that provides guidance for an object to move along a prescribed path. For example, "track" includes: a track with grooves, a track with protrusions, a track with teeth, and a track with balls.

[0749] like Figure 53As shown, the first bearing housing 12 can move along the first inner track 14 under the action of the corresponding driving device. The first bearing housing 12 and the first inner track 14 form a kinematic pair, specifically, a prismatic pair in a kinematic pair. The second bearing housing 13 can move along the second inner track 17 under the action of the driving device. The second bearing housing 13 and the second inner track 17 form a kinematic pair. The first inner track 14 and the first outer track 15 form a kinematic pair. The second inner track 17 forms a kinematic pair with the second outer track 16.

[0750] like Figure 53 As shown, the first outer track 15 and the second outer track 16 can be installed on the twin-roll thin strip casting machine.

[0751] like Figure 53 As shown, the kinematic pair formed by the first bearing housing 12 and the first inner track 14, and the kinematic pair formed by the first inner track 14 and the first outer track 15, together form the second kinematic pair for the movement of the first roller 1 on the twin-roll thin strip casting machine; similarly, the kinematic pair formed by the second bearing housing 13 and the second inner track 17, and the kinematic pair formed by the second inner track 17 and the second outer track 16, together form another second kinematic pair for the movement of the second roller 2 on the twin-roll thin strip casting machine.

[0752] The first main shaft 10 and the first roller shaft have different meanings: the first main shaft 10 is real; the first roller shaft is the rotation center line of the first roller body 1, which is actually invisible and intangible.

[0753] The "second kinematic pair on which the first roller 1 moves on the twin-roll thin strip casting machine" and the "other second kinematic pair on which the second roller 2 moves on the twin-roll thin strip casting machine" can be configured simultaneously or one of them can be configured; the specific selection depends on whether the first roller 1 and the second roller 2 need to move.

[0754] like Figure 53 As shown, when no floating control step occurs, both rollers are located on the reference plane 8.

[0755] In the floating control process, under the action of the corresponding driving force, the first bearing seat 12 moves along the first inner track 14, and the first inner track 14 moves along the first outer track 15; and / or, the second bearing seat 13 moves along the second inner track 17, and the second inner track 17 moves along the second outer track 16, while the first outer track 15 and the second outer track 16 remain relatively stationary to allow relative movement between the two rollers. Specifically, as... Figures 53 to 54 In the floating control steps shown, the first roller shaft is controlled to move on the set motion trajectory 18. Here, "relative motion" refers to the first roller body 1 rotating around the second roller shaft.

[0756] It is understandable that "the first roller 1 rotates around the second roller shaft" and "the first roller 1 rotates around the second roller 2" have the same meaning; during the process of "the first roller 1 rotating around the second roller shaft", the opening of the roller gap 3 is constant.

[0757] Optionally, with the above structure, the second kinematic pair can include one or more of the following kinematic pairs:

[0758] A kinematic pair that causes the first roller body 1 to rotate around the second roller shaft;

[0759] A kinematic pair that causes the second roller body 2 to rotate around the first roller shaft;

[0760] A kinematic pair that causes the direction of the velocity of the first roller 1 and / or the direction of the velocity of the second roller 2 to move in a direction perpendicular to the reference plane 8;

[0761] A kinematic pair that causes the direction of the velocity of the first roller 1 and / or the direction of the velocity of the second roller 2 to move in a direction oblique to the reference plane 8;

[0762] A kinematic pair that causes the first roller body 1 to rotate about any axis parallel to the first roller shaft;

[0763] A kinematic pair that causes the second roller 2 to rotate about any axis parallel to the second roller shaft.

[0764] The roller system includes a first roller body 1 and a second roller body 2. The roller system is movable, and the movement of the roller system is achieved through a first kinematic pair. The movement can be translational and / or rotational. For example, the roller system is mounted on the twin-roll thin strip casting machine via a linear guide rail, thereby achieving translation. The movement of the guide rail constitutes the first kinematic pair, which is a prismatic pair. Alternatively, the roller system is mounted on the twin-roll thin strip casting machine via a second rotating shaft, thereby achieving rotation. The movement around the second rotating shaft constitutes the first kinematic pair, which is a revolute pair.

[0765] It should be noted that the key innovation of the twin-roll thin strip casting machine device in Embodiment 11 of this invention lies in the fact that those skilled in the art are currently unaware that the floating of one direction of the roll gap 3 in the "bidirectional periodic floating or bidirectional non-periodic floating of the roll gap in conventional technology" is harmful. In the process of bidirectional periodic floating or bidirectional non-periodic floating of the roll gap 3 in conventional technology, both directions of the roll gap 3 floating are indispensable. The relative motion between the two rolls corresponding to each direction must cancel each other out on the change in the placement plane for the process to proceed. In other words, those skilled in the art recognize that after the relative motion between the two rolls changes the placement plane, it is necessary to rely on the relative motion between the two rolls to reset the placement plane, resulting in the reciprocating motion of the Nip point. This will have a significant negative impact on process stability and / or billet quality, which is the key to the structural innovation of the twin-roll thin strip casting machine device. Those skilled in the art, based on the patent application documents of this invention, can achieve the movement of the roll system through the first kinematic pair by setting it according to the structural needs of the twin-roll thin strip casting machine device itself, which will not be elaborated further here.

[0766] When the absolute value of the displacement of the first roller 1, the second roller 2, or the Nip point in the reference direction reaches the distance threshold, the first roller 1 stops rotating around the second roller shaft, and the floating control step ends; then, the compensation control step is executed.

[0767] like Figures 54 to 55 In the compensation control steps shown, the reference plane 8 is set to a preset position, the first bearing seat 12 and the first inner track 14 remain stationary, the first inner track 14 and the first outer track 15 remain relatively stationary, the second bearing seat 13 and the second inner track 17 remain relatively stationary, the second inner track 17 and the second outer track 16 remain relatively stationary, the first roller body 1 and the first outer track 15 remain relatively stationary, and the second roller body 2 and the second outer track 16 remain relatively stationary. The roller system is driven by the corresponding driving device to rotate counterclockwise around the second roller shaft by a certain angle, so that the two roller shafts return to the reference plane 8.

[0768] In the floating control step, the first roller 1 rotates about the second roller shaft, forming a revolute joint in the kinematic pair; in the compensation control step, the roller system rotates about the second roller shaft, forming a revolute joint in the kinematic pair. Both the first roller 1 and the roller system rotate about the second roller shaft, which is the common axis of rotation for both the first roller 1 and the roller system.

[0769] like Figure 55 and 53As shown, after the compensation control step is completed, the placement plane returns to the reference plane 8. At this time, because the relative positions of the first bearing seat 12, the second bearing seat 13, the first inner track 14, the second inner track 17, the first outer track 15, and the second outer track 16 have changed during the previous real-time floating control step, a support mechanism reset step needs to be performed to facilitate the subsequent implementation of the floating control step. It should be noted that the support mechanism of the roller system includes at least: the first bearing seat 12, the second bearing seat 13, the first inner track 14, the second inner track 17, the first outer track 15, and the second outer track 16. The support mechanism reset step includes: keeping the first roller body 1 and the second roller body 2 stationary relative to the ground, and adjusting the first bearing seat 12, the second bearing seat 13, the first inner track 14, the second inner track 17, the first outer track 15, and the second outer track 16 to return them to their original positions. Figure 53 The initial position is shown to facilitate the continued implementation of floating control by the second kinematic pair. It is understood that in specific industrial control, the support mechanism reset step can be performed simultaneously with the placement of the plane, either partially or completely offset, without affecting the compensation control steps.

[0770] Optionally, such as Figure 56 As shown, in another embodiment, the twin-roll thin strip casting machine includes a first main shaft 10, a second main shaft 11, a first bearing seat 12, a second bearing seat 13, a first inner track 14, and a first outer track 15. The first main shaft 10 of the first roll 1 is mounted in the first bearing seat 12; the second main shaft 11 of the second roll 2 is mounted in the second bearing seat 13; the first bearing seat 12 is movably mounted on the first inner track 14; the first inner track 14 is movably mounted on the first outer...

Claims

1. A method for controlling the roll gap in a twin-roll thin strip process, wherein a roll system is mounted on a twin-roll thin strip casting machine, the roll system comprising a first roll and a second roll arranged opposite each other for preparing a billet, the roll shaft of the first roll being called the first roll shaft, and the roll shaft of the second roll being called the second roll shaft; the plane in which the first roll shaft and the second roll shaft are located is called the placement plane of the roll system; the minimum distance between the first roll and the second roll is called the roll gap; the midpoint of the roll gap is called the Nip point; the moving speed of the billet at the Nip point is called the preparation speed; the moving speed of the Nip point caused by the relative movement between the first roll and the second roll is called the floating speed of the Nip point; The first roll and / or the second roll are movably arranged on the twin-roll thin strip casting machine to allow the roll gap to be adjustable; in its natural state, the plane containing the first roll shaft and the second roll shaft is called the reference plane; in its natural state, the direction of the production speed is called the reference direction; characterized in that the method includes the steps of: During the preparation process, the relative movement between the first roller and the second roller is controlled so that the placement plane undergoes multiple first rotations; during the occurrence of the multiple first rotations, the inner product of the floating speed and the preparation speed is always greater than zero or always less than zero; the multiple first rotations occur continuously or partially continuously.

2. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: During the preparation process, the placement plane only undergoes the first rotation.

3. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: During part or all of the time of a single first rotation, the opening of the roll gap remains constant; or, between two consecutive first rotations, relative movement occurs between the first and second rolls, but the inner product of the floating speed and the preparation speed is always equal to zero, and the placement plane remains unchanged.

4. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: During one of the first rotations, the relative motion between the first roller and the second roller includes one or more of the following relative motion modes: the first roller rotates around the second roller shaft; the second roller rotates around the first roller shaft; the direction of the velocity of the first roller and / or the direction of the velocity of the second roller are perpendicular to the reference plane; the direction of the velocity of the first roller and / or the direction of the velocity of the second roller are oblique to the reference plane; the first roller rotates around any axis parallel to the first roller shaft; the second roller rotates around any axis parallel to the second roller shaft.

5. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: During the first rotation, the angle between the direction of the floating speed and the direction of the preparation speed is greater than 120 degrees.

6. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: The first rotation occurs twice consecutively. During the first rotation, the angle between the direction of the floating velocity and the reference direction remains unchanged. During the second rotation, the angle between the direction of the floating velocity and the reference direction remains unchanged. The direction of the floating velocity in the first rotation and the direction of the floating velocity in the second rotation are perpendicular.

7. The roll gap control method for a twin-roll thin strip process according to claim 1, characterized in that: During one of the first rotations, the direction of the floating velocity does not change, and the direction of the floating velocity is perpendicular to the reference plane; or, during one of the first rotations, the direction of the floating velocity does not change, and the direction of the floating velocity is perpendicular to the reference direction.

8. A method for controlling the roll gap in a twin-roll thin strip process according to any one of claims 1-7, characterized in that: During the first rotation, the absolute value of the floating speed is in the range of 0.1 to 9000 micrometers per second; and / or, the frequency of the first rotation is in the range of 0.01 to 10 Hz.

9. A method for controlling the roll gap in a twin-roll thin strip casting process, wherein the roll system is movably mounted on a twin-roll thin strip casting machine, the roll system comprising a first roll and a second roll arranged opposite each other for preparing a billet; the roll shaft of the first roll is a first roll shaft, and the roll shaft of the second roll is a second roll shaft; the minimum distance between the first roll and the second roll is called the roll gap; the midpoint of the roll gap is called the Nip point; in its natural state, the plane containing the first roll shaft and the second roll shaft is called a reference plane, and the direction of the moving speed of the billet at the Nip point is called a reference direction; the plane containing the first roll shaft and the second roll shaft is called the placement plane of the roll system; the first roll and / or the second roll are movably mounted on the twin-roll thin strip casting machine so that the roll gap is adjustable; characterized in that... The method includes: a floating control step: controlling relative motion between the first roller and the second roller to cause the roller gap to float and the placement plane to change; a compensation control step: controlling the roller system to move as a whole on the twin-roll thin strip casting machine, and the placement plane to change; wherein the changes to the placement plane caused by the floating control step and the changes to the placement plane caused by the compensation control step are partially or completely canceled out.

10. The roll gap control method for a twin-roll thin strip process according to claim 9, characterized in that: The compensation control step is initiated when the current position of the first roller and / or the second roller deviates from the reference position in the reference direction by a distance threshold greater than or equal to the reference plane.

11. The roll gap control method for a twin-roll thin strip process according to claim 10, characterized in that: The distance threshold is in the range of 0 to 270 millimeters.

12. The roll gap control method for a twin-roll thin strip process according to claim 9, characterized in that: In the compensation control step, the roller system is controlled to move to a preset position to change the placement plane, thereby partially or completely offsetting the change in the placement plane caused by the floating control step.

13. The roll gap control method for a twin-roll thin strip process according to claim 12, characterized in that: The preset position includes one or more of the following positions: the initial position of the roller system; the preset position of the first roller and / or the second roller on the twin-roll thin strip casting machine; and the preset position range of the first roller and / or the second roller on the twin-roll thin strip casting machine.

14. The roll gap control method for a twin-roll thin strip process according to claim 9, characterized in that: The floating control steps include the steps of the roll gap control method for the twin-roll thin strip process as described in any one of claims 1 to 8.

15. The roll gap control method for a twin-roll thin strip process according to claim 9, characterized in that: The overall motion of the roller system includes one or more of the following motion modes: the roller system rotates around the second roller shaft; the roller system rotates around the first roller shaft; the roller system moves linearly relative to the ground in a direction perpendicular to the reference plane; the roller system moves linearly relative to the ground in a direction oblique to the reference plane; the roller system rotates around any axis parallel to the first roller shaft or the second roller shaft.

16. The roll gap control method for a twin-roll thin strip process according to claim 9, characterized in that: The timing relationship between the floating control step and the compensation control step includes one or more of the following: the floating control step and the compensation control step are performed sequentially; the floating control step and the compensation control step are initiated sequentially and partially overlap; the floating control step and the compensation control step are performed simultaneously, but the changes to the placement plane by the floating control step and the compensation control step are not synchronized; the floating control step and the compensation control step are performed simultaneously, and the changes to the placement plane by the floating control step and the compensation control step are synchronized.

17. A twin-roll thin strip casting machine apparatus for using a roll gap control method in a twin-roll thin strip process according to any one of claims 9 to 16, wherein a roll system is disposed on the twin-roll thin strip casting machine apparatus, the roll system comprising a first roll body (1) and a second roll body (2); the roll shaft of the first roll body (1) is a first roll shaft, and the roll shaft of the second roll body (2) is a second roll shaft; the plane in which the first roll shaft and the second roll shaft are located is called the placement plane of the roll system; characterized in that: The roller system is movably mounted on the twin-roll thin strip casting machine via a first kinematic pair, so that the roller system moves on the twin-roll thin strip casting machine in an overall motion manner; the first roller body (1) and / or the second roller body (2) are movably mounted on the twin-roll thin strip casting machine via a second kinematic pair, so that relative motion occurs between the first roller body (1) and the second roller body (2); wherein, the change of the placement plane by the movement of the roller system and the change of the placement plane by the relative motion between the first roller body (1) and the second roller body (2) are partially or completely canceled out.

18. The twin-roll thin strip casting machine apparatus according to claim 17, characterized in that: The twin-roll thin strip casting machine also includes a first main shaft (10), a second main shaft (11), a first bearing seat (12), a second bearing seat (13), a first inner track (14), and a first outer track (15); the first main shaft (10) of the first roll body (1) is installed in the first bearing seat (12); the second main shaft (11) of the second roll body (2) is installed in the second bearing seat (13); the first bearing seat (12) is movably mounted on the first inner track (14); the first inner track (14) is movably mounted on the first outer track (15).

19. The twin-roll thin strip casting machine apparatus according to claim 17, characterized in that: The second kinematic pair includes one or more of the following kinematic pairs: a kinematic pair that causes the first roller (1) to rotate about the second roller shaft; A kinematic pair that causes the second roller (2) to rotate around the first roller shaft; a kinematic pair that causes the direction of the velocity of the first roller (1) and / or the direction of the velocity of the second roller (2) to move in a direction perpendicular to the reference plane (8); a kinematic pair that causes the direction of the velocity of the first roller (1) and / or the direction of the velocity of the second roller (2) to move in a direction oblique to the reference plane (8); a kinematic pair that causes the first roller (1) to rotate around any axis parallel to the first roller shaft; a kinematic pair that causes the second roller (2) to rotate around any axis parallel to the second roller shaft.

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