A method and apparatus for the angular movement of the crystallization roll of a twin roll casting and extrusion

Abstract

The present application relates to a method and device for producing a deflection angle movement of a crystallization roll, wherein, compared with the conventional technology, the roll gap opening changes relatively little or does not change at all, the formation of an air gap at the meniscus is inhibited, the heat transfer between the crystallization roll and the cast material is improved, the cast strip quality is improved, and the uniformity of the cast strip thickness and the process stability are improved.

Description

Technical Field

[0001] This invention belongs to the technical field of twin-roll thin strip casting-extrusion (twin-roll thin strip casting-extrusion is also known as twin-roll casting and rolling, twin-roll thin strip continuous casting), specifically relating to a method and apparatus for the deflection angle movement of the crystallizing roll in twin-roll casting-extrusion. Background Technology

[0002] The twin-roll strip milling process was proposed by the British metallurgist Bessemer around 1850, as detailed in "On Manufacture of Continuous Sheets of Malleable Iron and Steel Direct from Fluid Metal" (Journal of Metals, 1965). In this process, two crystallizing rolls are placed parallel to each other and rotate in opposite directions, with a gap between them. The minimum distance between the two rolls is called the roll gap, and the midpoint of the roll gap is called the Nip point. The roll gap opening refers to the minimum distance between the two rolls. When there is no roll gap floating, the plane containing the roll axes is called the reference plane. The roll axis refers to the axis of rotation of the roll; it is a virtual line around which the roll rotates. In the field of twin-roll strip milling, in three-dimensional space, the Kiss point is actually a line, but for many years, researchers have used "Kiss point" to represent "Kiss line." Similarly, the Nip point is also a line, but for many years, researchers have used "Nip point" to represent "Nip line."

[0003] Chinese patent application number 2021101226378 discloses a method for characterizing the transport behavior within the molten pool during twin-roll casting. The theoretical basis of this tracing method is the turbulent partitioning phenomenon within the molten pool, first discovered by the inventors of this application. 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). Based on the discovered "turbulent partitioning phenomenon in the molten pool," the inventors combined "turbulent diffusion theory" with "solid-liquid diffusion theory" to propose the tracing method. Additionally, Chinese patent application number 2021112909655 discloses a method for measuring the Kiss angle in a twin-roll casting molten pool. The inventors clarified the advantages and disadvantages of the tracer method through experiments. To overcome the shortcomings of the tracer method, based on the "segregation theory" and the fact that "macroscopic segregation is difficult to eliminate through post-processing," the inventors proposed the Kiss angle measurement method. Thus, the transport process within the molten pool of twin-roll thin strip can finally be studied experimentally. Regarding the development process of the billet shell within the molten pool of twin-roll thin strip, the inventors, based on tracer experiments and Kiss angle measurement experiments, discovered that the billet shell within the molten pool is actually like an attached... Figure 1 It developed as shown.

[0004] In twin-roll thin strip processing, the initial solidification process that occurs at the meniscus is considered to have a crucial impact on the quality of the cast strip. The rotation of the crystallizing roll carries gas into the space between the cast metal and the crystallizing roll, leading to a variety of problems, including heat transfer and surface quality of the cast strip. However, for many years, there has been no good research or solution for the entrapment of gas as the crystallizing roll rotates.

[0005] Those skilled in the art believe that roll gap floating can improve the quality of the cast strip and enhance process stability. Roll gap floating refers to the movement of at least one of the two crystallizing rolls by a drive device, causing a change in the relative position of the two crystallizing rolls. The point of minimum distance between the two crystallizing rolls is called the roll gap, and the midpoint of the roll gap is called the Nip point. In three-dimensional space, the roll gap is a plane, and the Nip point is a line. The roll gap opening refers to the minimum distance between the two crystallizing rolls. The roll axis refers to the axis of rotation of the crystallizing roll when it rotates; in reality, the roll axis is an invisible and intangible center line of rotation.

[0006] Chinese patent document with application number 2017800317704 discloses a method for reducing vibration when operating a twin-roll thin strip continuous casting machine, as shown in the appendix. Figure 2As shown, the main technical solution is to sacrifice the uniformity of the casting strip thickness and cause the crystallizing roller clamping force to fluctuate in both directions in exchange for process stability. From around 2000 to the present, in more than 20 years, this method has only achieved commercial production of a very few steel grades and has great limitations. The two-phase region of the steel grade cannot be too wide or too narrow.

[0007] Chinese patent document with application number 2007101853779 discloses a vibrating twin-roll thin strip casting and rolling mill, as shown in the appendix. Figure 3 As shown, the main technical solution is single-sided crystallization roller vibration. However, this method still leads to changes in the thickness of the casting strip. For reference, see: "A review of the twin-roll casting process for complex section products" (ISIJ International, 2020, pp. 2165-2175).

[0008] Chinese patent document with application number 2022101047141 discloses a method for improving the stability of a crystallizing roll by yielding motion, as shown in the appendix. Figure 4 As shown, the main technical solution is that the roll gap floats obliquely in both directions. However, Chinese patent document with application number 2022101047141 states that the technical objective is to reduce the movement resistance of the billet shell so that the billet shell can smoothly converge at the bottom of the molten pool; the technical effect of the specific technical solution described will cause fluctuations in the thickness of the thin strip.

[0009] Existing roll gap floating technology solutions do not consider the impact on the thickness of the cast strip.

[0010] Chinese patent document application number 2022103431545 discloses a method for controlling the stability of the cast strip thickness in twin-roll thin strip continuous casting and introduces the importance of the uniformity of the cast strip thickness. This Chinese patent document argues that the thickness stability of the cast strip is crucial to the production stability of the thin strip continuous casting production line: the stability of the cast strip is directly related to its surface quality; fluctuations in the cast strip thickness easily lead to irregular pits on the surface; instability in the cast strip thickness directly affects subsequent hot rolling; and fluctuations in the cast strip thickness affect the control of rolling force and hot rolling reduction, etc., causing a sharp increase in the instability of hot rolling.

[0011] The problem with existing technology is:

[0012] The roll gap floating process will deteriorate the surface quality of the cast strip;

[0013] The roll gap floating process can cause changes in the thickness of the casting strip, which in turn affects the stability of the process;

[0014] Because the thickness fluctuation of the cast strip must be taken into account, the range of motion of the motion roller is limited. This limited range of motion is insufficient to meet the actual needs of complex metal compositions. Due to the very limited range of motion of the motion roller, it is very difficult to control the stability of the process.

[0015] During the roll gap floating process, fluctuations in the thickness of the cast strip are detrimental to the quality of the final product. Summary of the Invention

[0016] The inventors have discovered through research that, using the method described in the attached figure... Figure 2 To be continued Figure 4 The existing technical solution shown introduces additional casting quality problems. Evidence of this is that analysis of the molten pool ingot reveals "water ripple-like horizontal stripes" on the surface of the molten pool ingot on the side in contact with the moving crystallizing roller, as shown in the attached image. Figure 5 As shown; wherein, the molten pool ingot is obtained through an "emergency stop method". The inventors have described the "emergency stop method" in detail in Chinese patent application No. 2021101226378. The specific implementation process of the "emergency stop method" is as follows: during the casting and rolling process, the rotation of the crystallizing rolls is suddenly stopped, the injection of molten metal between the two crystallizing rolls is simultaneously stopped, and water is rapidly sprayed between the two crystallizing rolls to promote the solidification of the metal between the two crystallizing rolls, thereby obtaining a molten pool ingot. The "water ripple-like horizontal stripes" deteriorate the heat transfer performance between the crystallizing rolls and the molten metal. This is because a large amount of gas is entrained from the meniscus into the space between the crystallizing rolls and the metal being cast, forming an air gap, which hinders heat transfer. During the rolling process in the molten pool, the "water ripple-like horizontal stripes" are flattened again under external force. During the flattening process, gas, oxides, and impurities from the air gap depressions may enter the interior of the casting strip, which is detrimental to the quality of the casting strip. The "water ripple-like horizontal stripes" also deteriorate the surface quality of the casting strip. The inventors believe that the "water ripple-like horizontal stripes" are caused by the movement pattern of the crystallizing roller, which prevents the gas entering from the meniscus from being discharged smoothly.

[0017] The twin-roll thin-strip process belongs to the moving crystallizer technology. The inventors have discovered through research that, for the moving crystallizer technology, the meniscus air gap formation process is as follows: Figure 6As shown in the reference: (Mianguang XU, Mihaiela ISAC and Roderick IL GUTHRIE*) "A Numerical Simulation of Transport Phenomena during the Horizontal Single Belt Casting Process Using an Inclined Feeding System" (Metallurgical and Materials Transactions B, 2018, pp. 1003-1013). According to the appendix... Figure 6 Regarding the twin-roll thin-strip process, the inventors believe that its air gap morphology is as shown in the attached figure. Figure 7 As shown, attached Figure 7 Enlarged view of the air gap region at the crescent surface (with appendix) Figure 8 As shown.

[0018] Based on the principles of the meniscus air gap morphology described above, and the attached... Figure 2 To be continued Figure 4 The invention addresses the shortcomings of existing technical solutions by proposing an innovative approach. It posits that the rotation of one crystallizing roller around the axis of another is most advantageous for venting gas from the air gap. This is because the width of the air gap gradually decreases along the rotation direction of the crystallizing rollers. Furthermore, if one crystallizing roller rotates around the axis of another, the compression effect on the air gap gradually decreases along the rotation direction, perfectly matching the trend of air gap width variation. In other words, the compression effect does not confine the gas between the cast metal and the crystallizing rollers, which is entirely different from the technical effect of traditional solutions. Currently, compared to traditional technologies, the technical solution provided in this patent application is most advantageous for eliminating air gaps.

[0019] According to the appendix Figure 6 To be continued Figure 8 Through research and practice, the inventors discovered that in twin-roll casting experiments using industrial pure aluminum, if the trajectory of the moving roller is set as an arc segment during the roll gap floating process, with the concave side of the arc segment facing the other crystallizing roller and the center of the arc falling near the roller shaft of the other crystallizing roller, then the desired effect can be achieved. Figure 9 The effect shown. (Attached) Figure 9In the process of obtaining the molten pool ingot through the "emergency stop method," the "water ripple-like horizontal stripes" on the surface of the contact side with the crystallizing roll almost disappear. This indicates that the practical technical solution derived from the original theory in this patent application can significantly optimize the wetting behavior of the melt at the meniscus and promptly remove the gas entrained by the rotation of the crystallizing roll. As a result, it is foreseeable that the heat transfer effect between the crystallizing roll and the cast metal will be improved. Furthermore, by reducing the content of gas, oxides, and impurities entering the casting strip during the flattening process of the "water ripple-like horizontal stripes," the quality of the casting strip, especially the surface quality, can be effectively improved.

[0020] The inventors have discovered through research that, using the method described in the attached figure... Figure 3 To be continued Figure 4 The existing technical solution shown will produce visible "horizontal lines" on the surface of the casting strip exiting the molten pool, as shown in the attached image. Figure 10 As shown, the "horizontal lines" are evenly distributed along the direction of the casting strip movement. This is caused by the change in the roll gap opening and the change in the thickness of the casting strip during the movement of the crystallizing roll.

[0021] Through research, the inventors discovered that in twin-roll casting experiments using industrial pure aluminum, if the trajectory of the moving roller is set as an arc segment during the roll gap floating process, with the concave side of the arc segment facing the other crystallizing roller and the center of the arc falling near the roller shaft of the other crystallizing roller, not only can the desired effect be achieved... Figure 9 The beneficial effects shown are for ingots cast within the molten pool, and for the casting strip exiting the molten pool, they can achieve additional... Figure 11 The beneficial effects shown are illustrated below. Figure 11 In this study, no visible "horizontal lines" were found on the surface of the cast strip exiting the molten pool, indicating that the uniformity of the cast strip thickness was significantly improved compared to existing technologies.

[0022] Further research by the inventors revealed that... Figure 12 It is attached Figure 2 A comparison of the technical solution shown with the technical solution proposed in the patent application of this invention is attached. Figure 2 The thickness fluctuation of the cast strip produced by the technical solution shown is estimated to be no more than 70 micrometers; while the attached Figure 12 In this invention, the thickness fluctuation is estimated to be no more than 5 micrometers. This indicates that even under relatively primitive laboratory conditions, the technical solution proposed in this patent application can greatly suppress the thickness fluctuation of the cast strip.

[0023] In summary, to overcome the shortcomings of traditional technologies, this invention provides a method for the angular movement of a crystallizing roll in twin-roll casting and extrusion. The twin-roll casting and extrusion system includes a first crystallizing roll and a second crystallizing roll. One of the first and second crystallizing rolls is an angular movement roll, and the other is a fixed roll. For example, the first crystallizing roll is an angular movement roll, and the second crystallizing roll can be a fixed roll. Taking any plane φ perpendicular to the roll axis of the first crystallizing roll, at any time, the projection of the first crystallizing roll onto the plane φ is a circle C1 centered at point O1, and the projection of the second crystallizing roll onto the plane φ is a circle C2 centered at point O2. On the plane φ, the angular movement trajectory of the center of the angular movement roll is an arc segment, and the center of the arc segment coincides with a point within 10 cm of the center of the fixed roll.

[0024] Furthermore, in a method for angular movement of the crystallizing roll in twin-roll casting and extrusion, the center of the arc segment on the plane φ coincides with the center of the fixed roll.

[0025] Furthermore, a method for the angular movement of a crystallizing roll used in twin-roll casting and extrusion, wherein the angular movement of the center of the angular movement roll on the arc segment follows a sinusoidal law.

[0026] Furthermore, a method for angular motion of a crystallizing roll in twin-roll casting and extrusion, wherein the reciprocating motion frequency of the center of the angular motion roll on the arc segment is in the range of 0.01 to 100 Hz.

[0027] Furthermore, a method for angular movement of the crystallizing roll in twin-roll casting extrusion, wherein the length of the arc segment is in the range of 1 to 10 centimeters.

[0028] Furthermore, a method for angular movement of the crystallizing roll in twin-roll casting extrusion, wherein the length of the arc segment is in the range of 1 to 10 millimeters.

[0029] Furthermore, a method for the angular movement of the crystallizing roll in twin-roll casting extrusion is provided, wherein the length of the arc segment does not exceed 100 micrometers. The length of the arc segment can vary on a very large scale, ranging from several centimeters to millimeters or micrometers, to adapt to the complex requirements of actual thin strip materials.

[0030] Furthermore, the present invention provides an apparatus for implementing the skewed motion of a crystallizing roll in twin-roll casting and extrusion. The apparatus includes a first crystallizing roll, a second crystallizing roll, a distribution system, a side sealing device, a main frame, an arc-shaped section of the frame, a bearing housing, a drive system, a monitoring system, and a cooling system. The first crystallizing roll and / or the second crystallizing roll are the skewed motion rolls. The bearings of the skewed motion rolls are mounted on the bearing housings, and the bearing housings are located on the arc-shaped section of the frame. The distance between the center of the arc-shaped section of the frame and the axis of the other crystallizing roll is no more than 20 centimeters. By constraining the movement path of the bearing housings through the arc-shaped section of the frame, the movement trajectory of the skewed motion rolls is an arc segment.

[0031] Furthermore, an apparatus for a method of angular movement of the crystallizing roll in twin-roll casting and extrusion, wherein the center of the arc segment of the frame is above the axis of the roll body of the other crystallizing roll.

[0032] The advantages of the technical solution proposed in this invention patent application are as follows:

[0033] Improving the uniformity of the casting strip thickness, and even potentially achieving the ideal effect of completely consistent casting strip thickness, is expected to enable the direct preparation of ultra-precision, ultra-high value-added casting strips.

[0034] Improve the heat transfer performance of the crystallizing roll by improving the wettability of the meniscus melt and reducing the "water ripple-like horizontal stripes".

[0035] Improve the quality of the cast strip, especially the surface quality, by improving the wettability of the meniscus melt and reducing the "water ripple-like horizontal stripes".

[0036] The motion roller has a larger range of motion, which allows for better control of process stability;

[0037] Reducing the variation range of roll gap will decrease the fluctuation range of casting and rolling force, thereby enhancing process stability;

[0038] Expand the range of steel grades that can be produced using the twin-roll strip process.

[0039] Maintaining a constant roll gap while applying extrusion through the movement of the crystallizing roll is also an important objective in the control of extrusion pressure in the twin-roll thin strip process. Attached Figure Description

[0040] Figure 1 This is a brief schematic diagram of the experimental results obtained by implementing the tracer method and the Kiss angle measurement method using a laboratory twin-roll casting machine.

[0041] Figure 2 This is a schematic diagram of the zero-angle roll gap bidirectional floating method.

[0042] Figure 3This is a schematic diagram of the vertical roll gap bidirectional floating method.

[0043] Figure 4 This is a schematic diagram of the inclined roll gap bidirectional floating method.

[0044] Figure 5 This is a schematic diagram of the "water ripple-like horizontal stripes" on the surface of the ingot when the traditional roll gap floating method is used for emergency stop.

[0045] Figure 6 This is a schematic diagram of the air gap formation based on the moving crystallizer technology, obtained from simulation using the VOF multiphase flow model.

[0046] Figure 7 This is a schematic diagram of the air gap at the meniscus under the conditions of twin-roll thin strip manufacturing.

[0047] Figure 8 yes Figure 7 An enlarged schematic diagram of the air gap region on the meniscus.

[0048] Figure 9 This is a schematic diagram showing that the surface of the molten pool ingot in contact with the moving crystallizing roller, obtained by using the technical solution in the present invention patent application, has no significant "water ripple-like horizontal stripes".

[0049] Figure 10 This is a schematic diagram of the "horizontal lines" on the surface of the casting strip when using the traditional roll gap floating method.

[0050] Figure 11 This is a schematic diagram showing that the surface of the casting strip is free of "horizontal lines" when the technical solution of this invention is adopted.

[0051] Figure 12 This is a schematic diagram comparing the changes in the thickness of the casting strip using the technical solution of this invention with that of a traditional technical solution.

[0052] Figure 13 This is a schematic diagram of Embodiment 1 of the present invention.

[0053] Figure 14 This is a partially enlarged schematic diagram of Embodiment 1 of the present invention.

[0054] Figure 15 This is a schematic diagram of the experimental results of Embodiment 1 of the present invention, in which only the first crystallizing roller is a moving roller.

[0055] Figure 16 This is a schematic diagram of a partial structure of a device for implementing the deflection angle movement of the crystallizing roll in twin-roll casting and extrusion according to Embodiment 2 of the present invention.

[0056] Figure 17 This is a schematic diagram of a partial structure of a device for implementing the deflection angle movement of the crystallizing roll in twin-roll casting and extrusion according to Embodiment 2 of the present invention.

[0057] Figure 18 This is a schematic diagram of the bearing housing moving along an arc-shaped track in Embodiment 2 of the present invention.

[0058] Figure 19 This is a schematic diagram of a partial structure of a device for implementing the deflection angle movement of the crystallizing roll in twin-roll casting and extrusion according to Embodiment 3 of the present invention.

[0059] The correspondence between the figure numbers in the following figures is as follows:

[0060] 1. First crystallizing roll, 2. Second crystallizing roll, 3. Roll gap, 4. Long-range shear thinning interface, 5. Molten pool, 6. Flow distribution device, 7. Casting strip, 8. Reference plane, 9. Concentric circle (concentric circle of the second crystallizing roll), 10. Upper edge of deflection angle ω, 11. Lower edge of deflection angle ω, 12. First path (circular arc segment), 13. Main frame, 14. Arc segment of the first frame, 15. First bearing housing, 16. Second bearing housing, 17. Hydraulic device, 18. Auxiliary hydraulic device, 19. Second (deflection angle movement) path, 20. Arc segment of the second frame. Implementation

[0061] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0062] For ease of explanation, it is agreed that the roller shaft of the first crystallizing roller 1 is called the first roller shaft, and the roller shaft of the second crystallizing roller 2 is called the second roller shaft. Take any plane φ perpendicular to the first roller shaft. Assuming no floating of the roller gap 3 occurs, the projection of the first crystallizing roller 1 onto plane φ is a circle C1 centered at point O1, where O1 is the projection of the first roller shaft onto plane φ; the projection of the second crystallizing roller 2 onto plane φ is a circle C2 centered at point O2, where O2 is the projection of the second roller shaft onto plane φ. The roller shaft is the axis of rotation of the crystallizing roller during its rotation.

[0063] In practice, the first crystallizing roller 1 and the second crystallizing roller 2 may vary due to load and / or have intentionally designed non-circular roller shapes. Therefore, the projections of the first crystallizing roller 1 and the second crystallizing roller 2 onto the plane φ are not perfectly circular. In this patent application, it is assumed that the projections of the first crystallizing roller 1 and the second crystallizing roller 2 onto the plane φ are perfectly circular. Example 1

[0064] Embodiment 1 of this invention discloses a method for the angular movement of the crystallizing roll in twin-roll casting and extrusion, such as... Figures 13 to 15 As shown, Figure 13 The image shows a constant-diameter twin-roll casting mill. To more clearly illustrate the core issues of this invention, the sprue and molten pool are not shown. The first crystallizing roll 1 and the second crystallizing roll 2 both have a radius of 250 mm; the casting and extrusion speed is in the range of 0.6~1.2 m / s; the roll gap is in the range of 0.75~2.75 mm; the metal produced is steel, but the cast and rolled metal can also be non-ferrous metal sheets / strips, multi-layer sheets / strips, high-entropy alloy sheets / strips, composite tubes / bars, and materials that may be prepared using twin-roll casting and extrusion in the future.

[0065] Figure 13 The local area in the image has been magnified, such as... Figure 14 As shown. The first crystallizing roller 1 is a moving roller, and the second crystallizing roller 2 is a fixed roller.

[0066] like Figure 13 As shown, in plane φ, concentric circle 9 is a circle concentric with C2 (the projection of the second crystallizing roller 2 onto plane φ), and the first route 12 (arc O) 1-1 O1O 1-2 It lies on concentric circle 9. The first route 12 can be denoted as arc O. 1-1 O1O 1-2 Due to the arc O 1-1 O1O 1-2 The corresponding angle is an acute angle; therefore, the first route 12 can also be represented as arc O. 1-1 O 1-2 In this application document, the first route 12 is denoted as arc O. 1-1 O 1-2 .

[0067] like Figure 13 As shown, A is a fixed point located on line segment O1O2. A is the midpoint of line segment O1O2, that is, A is the position of the Nip point when the roll gap does not float.

[0068] like Figure 13 As shown, in plane φ, O1A is ∠O 1-1 AO 1-2 The angle bisector.

[0069] Optionally, such as Figure 13 As shown, in plane φ, O1A is not ∠O 1-1 AO 1-2 The angle bisector.

[0070] Optionally, the first route 12 (arc O) 1-1 O 1-2Excluding point O1, that is, the motion path 12 is located on one side of line O1A, that is, the upper side 10 of the deflection angle ω and the lower side 11 of the deflection angle ω are both located on the same side of line O1A.

[0071] like Figure 13 As shown, the first route 12 (arc O) 1-1 O 1-2 The length of the ) is 900 micrometers.

[0072] Optionally, the first route 12 (arc O) 1-1 O 1-2 The length of the ) is tens of micrometers, which is less than 100 micrometers.

[0073] Optionally, the first route 12 (arc O) 1-1 O 1-2 The length of the ) ranges from 1 to 10 millimeters.

[0074] Optionally, the first route 12 (arc O) 1-1 O 1-2 The length of the ) ranges from 1 to 10 centimeters.

[0075] like Figure 13 As shown, the first roller moves along the first path 12 at a frequency of 50 Hz / second, following a sinusoidal law. Following a sinusoidal law means that the speed of the first roller follows a sinusoidal pattern.

[0076] Optionally, the first roller moves along the first path 12, and the frequency and / or amplitude of its reciprocating motion are adjusted in real time according to process parameters. These process parameters include rolling force, also known as the crystallizing roll clamping force.

[0077] Optionally, the roller of the first roller 1 moves on the first path 12, and the frequency of its reciprocating motion can be from a very low frequency (e.g., 0.01 Hz / s) to a very high frequency (e.g., 100 Hz / s).

[0078] Optionally, such as Figure 13 As shown, the first crystallizing roller 1 performs a deflection angle movement once, then it becomes a fixed roller, while the second crystallizing roller 2 performs a similar deflection angle movement. This process is repeated, meaning the first crystallizing roller 1 and the second crystallizing roller 2 alternately become deflection angle movement rollers. This is based on the inventors' experimental findings that when only the first crystallizing roller 1 performs the deflection angle movement while the second crystallizing roller remains fixed, the following result is obtained: Figure 15The cast strip 7 shown is curved along the moving direction. This shape results in an uneven microstructure and is highly detrimental to the subsequent rolling process, affecting the overall stability of the process. The cast strip 7 is a Cu-Ni-Sn alloy, and its specific preparation method is as follows: the superheat of the alloy melt is in the range of 20 to 30 degrees Celsius; the total mass of the alloy melt cast in one operation is approximately 3.5 kg; the depth of the molten pool is controlled in the range of 35 to 50 mm; the roll gap is set at 2.5 mm; one crystallizing roll is a moving roll with a frequency of approximately 3 Hz and a movement amplitude of approximately 1.5 mm; the other crystallizing roll remains stationary. Figure 15 As can be seen, the casting strip 7 has undergone significant bending, with the concave side facing the moving crystallizing roller. Therefore, in the technical solution shown in Embodiment 1 of the present invention, optionally, the first crystallizing roller 1 and the second crystallizing roller alternately become moving rollers. This is beneficial to improving the flatness of the casting strip 7, and further beneficial to improving the quality of the casting strip 7 and the process stability.

[0079] like Figure 13 As shown, the first roller moves on the first path 12, O 1-1 and O 1-2 These are only two extreme points; the first roller may not always move in the same direction as O. 1-1 and / or O 1-2 Overlap, that is, if the length of the first route 12 is 50 micrometers, then the first roller shaft will move from O each time. 1-1 Along the first route 12 to O 1-2 Or from O 1-2 Along the first route 12 to O 1-1 The distance traveled was no more than 50 micrometers.

[0080] The beneficial effects of Embodiment 1 of the present invention are as follows: Figure 9 Appendix Figure 11 and attached Figure 12 As shown, it should be noted that the appendix... Figure 9 Appendix Figure 11 and attached Figure 12 This was not achieved using a specially designed and built twin-roll thin strip casting machine, but rather by utilizing existing auxiliary... Figure 3 The vibratory twin-roll casting machine shown employs a skillful technique: specifically, an arc-shaped stop is added to the outside of the vibrating crystallizing roll. This ensures that the moving crystallizing roll follows the required first path 12 during its movement. The distance between the center of the arc-shaped stop and the roller shaft of the fixed crystallizing roll does not exceed 20 mm. Considering that the diameter of the crystallizing roll used is 160 mm, while industrially produced crystallizing rolls can reach 800 mm in diameter, the inventors, based on the principle of geometric similarity, concluded that when the distance between the center of the first path 12 of the moving crystallizing roll and the roller shaft of the fixed crystallizing roll is within a range not exceeding 10 cm, the desired effect can be achieved. Figure 9and attached Figure 11 The effect.

[0081] It should be noted that the inventor believes that the appendix Figure 9 Appendix Figure 11 and attached Figure 12 The beneficial effects of this invention patent application are conclusively demonstrated from a qualitative analysis perspective. Example 2

[0082] A schematic diagram of a partial structure of a device for implementing the deflection angle movement of the crystallizing roll in twin-roll casting and extrusion, as disclosed in Embodiment 2 of the present invention, is shown below. Figures 16 to 18 As shown. Figure 16 The image shows a two-roll casting mill with equal diameters. The radius of the first crystallizing roll 1 and the second crystallizing roll 2 is 250 mm. The casting and extrusion speed does not exceed 1.2 m / s. The opening of the roll gap 3 does not exceed 7.75 mm. The metal being cast and extruded is steel material (such as silicon steel, carbon steel, weathering steel, etc.).

[0083] In embodiment 2 of the present invention, as Figure 16 As shown, the first crystallizing roller 1 is an angle-shifting roller, and the second crystallizing roller 2 is a fixed roller (the fixing device is not shown). The bearing of the first crystallizing roller 1 is set in the first bearing seat 15, and the bearing of the second crystallizing roller 2 is set in the second bearing seat 16; the first bearing seat 15 is movably set on the arc-shaped section 14 of the first frame; the arc-shaped section 14 of the first frame is movably set on the main frame 13.

[0084] like Figure 17 As shown, the first crystallizing roller 1 can move along the arc-shaped section 14 of the first frame under the drive of the hydraulic device 17.

[0085] like Figure 16 As shown, the first bearing housing 15 reciprocates along the first path 12. In plane φ, the center of the first path 12 falls near O2. Due to component deformation caused by errors and / or loads, the center of the first path 12 in plane φ cannot actually coincide with O2. Therefore, it is appropriate to describe it as "nearby". "Nearby" can be considered as a radius of 20 centimeters with O2 as the center. The "20 centimeters" comes from two aspects: first, the experimental data in Example 1; second, the variation in the thickness of the casting strip itself. There are currently reports on the preparation of 10-centimeter-thick cladding using a twin-roll thin strip process.

[0086] The first crystallizing roller 1 moves along the first route 12 at a frequency of 0.5 Hz and an amplitude of 2 mm. It is a reciprocating motion. The speed of the first crystallizing roller 1 can follow a sinusoidal law.

[0087] Optionally, the frequency and amplitude of the reciprocating motion of the first crystallizing roller 1 can range from very small values ​​to very large values, for example: the frequency ranges from 0.01 Hz to tens of Hz; the amplitude ranges from tens of micrometers to tens of millimeters.

[0088] Optionally, such as Figure 18 As shown, the arc-shaped section 14 of the first frame can be driven by the auxiliary hydraulic device 18 and moved under the constraint of the main frame 13 to change the distance between the first crystallizing roller 1 and the second crystallizing roller 2.

[0089] Figure 16 , Figure 17 , Figure 18 In the process, the bearing housing should have as little moving resistance as possible, for example, by designing grooves or using various types of rolling bearings at the contact surface between the main frame 13 and the bearing housing, so as to facilitate accurate acquisition of process data and precise control of the process. Example 3

[0090] A schematic diagram of a partial structure of a device for implementing the deflection angle movement of the crystallizing roll in twin-roll casting and extrusion, as disclosed in Embodiment 3 of the present invention, is shown below. Figure 19 As shown.

[0091] like Figure 19 As shown, the first bearing housing 15 is movably mounted on the arc-shaped section 14 of the first frame; the second bearing housing 16 is movably mounted on the arc-shaped section 20 of the second frame.

[0092] The first bearing housing 15 can reciprocate along the first path 12; the second bearing housing 16 can reciprocate along the second path 19 on the arc-shaped section 20 of the second frame.

[0093] like Figure 19 As shown, both the first crystallizing roller 1 and the second crystallizing roller 2 are angle-shifting rollers, and they can move alternately. That is, when the first crystallizing roller 1 moves at an angle, the second crystallizing roller 2 rotates in a fixed position; when the second crystallizing roller 2 moves at an angle, the first crystallizing roller 1 rotates in a fixed position. The purpose of this is to avoid... Figure 15 The bending phenomenon of the cast strip 7 shown.

[0094] The beneficial effect of Embodiment 3 of the present invention is that, compared with Embodiment 2, it can reduce or eliminate [the problem]. Figure 15 The bending phenomenon of the cast strip 7 shown is beneficial to the uniformity of the structure of the cast strip 7 and enhances the stability of subsequent processing.

[0095] The patent application for this invention discloses many classification methods for twin-roll casting machines: based on the difference in the diameter of the crystallizing rolls, twin-roll casting machines include equal diameter, different diameter, and variable diameter types; based on the arrangement of the two crystallizing rolls, twin-roll casting machines include horizontal, inclined, and vertical types; based on the billet extraction method, twin-roll casting machines include extraction along the direction of gravity, extraction at an angle of less than 180 degrees to the direction of gravity, and extraction in a direction completely opposite to the direction of gravity.

[0096] It should be noted that the embodiments described in this patent application can be used for any type of twin-roll casting machine.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.

Claims

1. A method for the angular movement of a crystallizing roll in twin-roll casting and extrusion, the twin-roll casting and extrusion system comprising a first crystallizing roll and a second crystallizing roll, wherein one of the first crystallizing roll and the second crystallizing roll is an angularly moving roll and the other is a fixed roll, taking any plane φ perpendicular to the roll axis of the first crystallizing roll, then at any time, the projection of the first crystallizing roll onto the plane φ is a circle C1 centered at point O1, and the projection of the second crystallizing roll onto the plane φ is a circle C2 centered at point O2, characterized in that: On the plane φ, the trajectory of the center of the deflection angle motion roller is a reciprocating motion along a circular arc segment. On the plane φ, the center of the circular arc segment coincides with the center of the fixed roller. The speed of the deflection angle motion of the center of the deflection angle motion roller on the circular arc segment follows a sinusoidal law.

2. The method for adjusting the angle of the crystallizing roll in twin-roll casting and extrusion according to claim 1, characterized in that: The reciprocating motion frequency of the center of the deflection angle motion roller on the arc segment is in the range of 0.01 to 100 Hz.

3. The method for adjusting the angle of the crystallizing roll in twin-roll casting and extrusion according to claim 1, characterized in that: The length of the arc segment is in the range of 1 to 10 centimeters.

4. The method for adjusting the angle of the crystallizing roll in twin-roll casting and extrusion according to claim 3, characterized in that: The length of the arc segment is in the range of 1 to 10 millimeters.

5. A method for adjusting the angle of the crystallizing roll in twin-roll casting and extrusion according to claim 3 or 4, characterized in that: The length of the arc segment does not exceed 100 micrometers.

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