Design method of fan-shaped section under heavy pressure of plate blank

Abstract

The invention provides a method for designing a fan-shaped section of a plate blank under heavy pressure, which belongs to the technical field of continuous casting and comprises the following steps of: respectively arranging at least two driving rollers on the inner arc and the outer arc of the fan-shaped section under heavy pressure; the driving roller arranged on the inner arc serves as an inner arc driving roller, and the inner arc driving roller is an integral roller; the transmission roller arranged on the outer arc serves as an outer arc transmission roller, and the outer arc transmission roller is a segmented roller; wherein the roller diameter of the inner arc transmission roller ranges from 250 mm to 450 mm; the length of the section of the outer arc driving roller is larger than 0 and smaller than or equal to 150 mm; the inner arc roller of the heavy reduction fan-shaped section is used as a reduction execution roller; and the inner arc driving roller is used as an execution roller under the heavy pressure of a single roller so as to complete the design of the fan-shaped section under the heavy pressure. By means of the method, the problems that in the prior art, according to the design scheme of the fan-shaped section under the slab heavy pressure, the number of pressing points is small, indentations exist, and stable production under the slab heavy pressure cannot be met can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of continuous casting, more particularly, to a design method of slab heavy press-down fan-shaped section. BACKGROUND

[0002] With the rapid development of manufacturing industry and science and technology, higher requirements are put forward for the internal quality of steel. As a new type of continuous steel casting process, wide and thick plate continuous casting technology has the advantages of high metal yield, low energy consumption per ton of steel, good product quality, etc., and has been widely used in the fields of large section square billet and wide and thick plate. However, with the increase of the section size of the casting billet, the internal cooling condition is obviously deteriorated, the columnar crystal in the solidification structure is developed, the residual liquid steel rich in solute segregation elements between dendrites tends to flow to equilibrium, resulting in more serious segregation, porosity and shrinkage hole defects of the casting billet. These defects are difficult to be effectively eliminated in the subsequent heating and rolling process, thereby affecting the quality of the final product. Traditional technologies, such as electromagnetic stirring and light press-down, are difficult to significantly improve the quality of the casting billet.

[0003] In order to solve the above problems, heavy press-down technology emerges as the times require. This technology is to press down the casting billet with a large deformation in a certain area of the two-phase zone of the casting billet, so that the press-down amount fully penetrates into the center of the casting billet, thereby achieving the process effect of welding the solidification shrinkage hole and even refining the center austenite grains, and reducing the rolling ratio of the slab by making the center of the casting billet dense, thereby improving the production efficiency and production cost of the casting billet.

[0004] At present, in the technology of slab heavy press-down, in addition to the difference in process ideas, the main difference is the difference in equipment scheme. There are three main popular schemes: (1) the equipment scheme of large roll diameter, only one 700-1000 mm large roll diameter press-down roll in the fan-shaped segment, the press-down roll is not segmented, and the other rolls only follow the movement and do not participate in the press-down. This scheme can indeed realize the press-down amount of more than 20 mm of single roll, and improve the deformation penetration rate of the press-down amount, but it has the defects of few press-down points and large roll spacing caused by large roll diameter, and once the cast slab is not solidified, there is a large bulge; (2) the equipment scheme of the fan-shaped segment and the traditional fan-shaped segment is the same, which is executed by four clamping cylinders, only the cylinder diameter and the roll diameter are increased, and the press-down capacity of a single fan-shaped segment is increased. The roll is still segmented roll, which increases the press-down amount of a single fan-shaped segment to a certain extent, but due to the use of segmented roll, the press-down amount of single roll cannot be increased, otherwise there will be a press mark, and the press-down amount of a single segment is also within 8 mm; (3) the equipment scheme of each roll in the fan-shaped segment can be independently pressed down, the roll diameter of the belt drive can be appropriately larger, and each roll adopts segmented roll. Due to the use of segmented roll, the press-down amount of single roll cannot be large, which is basically within 3 mm, otherwise there will be a press mark, which leads to the inability to realize large press-down, and due to the increase of roll diameter, the roll spacing is increased. Once the fan-shaped segment is located before the solidification end, the cast slab will produce a large bulge. If the length of the segmented roll is large, the segmented roll itself will produce a press mark, and even affect the production.

[0005] In summary, in the design scheme of the existing heavy press-down fan-shaped segment, due to the segmented roll for realizing heavy press-down, the press mark cannot be avoided, the whole cannot realize the press-down capacity of more than 5 mm of single roll, and due to the increase of roll diameter and roll spacing, the cast slab will produce a large bulge before solidification, so it is difficult to avoid the appearance of press mark and affect the normal and stable production. The equipment scheme which can realize the press-down amount of more than 20 mm of single roll can only have one press-down point, which greatly limits the process effect and cannot meet the stability of press-down effect under the condition of speed fluctuation, and due to the large roll diameter, the roll spacing is greatly increased. Once the unsolidified cast slab is located before the heavy press-down fan-shaped segment, the cast slab will produce an unimaginable bulge, thereby affecting the quality of the cast slab. That is, the current design scheme of slab heavy press-down fan-shaped segment has the problems of difficult realization of stable and safe production of more than 7 mm of single roll heavy press-down and realization of optimal press-down effect under different cast slab states.

[0006] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information which does not constitute prior art known to those skilled in the art. SUMMARY

[0007] In view of the above problems, the purpose of the present application is to provide a design method of slab heavy press-down sector, so as to solve the problem that the design scheme of slab heavy press-down sector in the prior art cannot meet the stable production of slab heavy press-down because of the few press-down points and the existence of press marks.

[0008] The present application provides a design method of slab heavy press-down sector, comprising the following steps: At least two transmission rollers are arranged on the inner arc and the outer arc of the heavy press-down sector respectively; The transmission roller arranged on the inner arc is used as an inner arc transmission roller, and the inner arc transmission roller adopts a whole roller; the transmission roller arranged on the outer arc is used as an outer arc transmission roller, and the outer arc transmission roller adopts a segmented roller; wherein the roll diameter of the inner arc transmission roller is 250mm-450mm; the length of the segmented part of the outer arc transmission roller is greater than 0 and less than or equal to 150mm; The inner arc roller of the heavy press-down sector is used as a press-down execution roller, and the inner arc transmission roller is used as a single-roller heavy press-down execution roller, so as to complete the design of the heavy press-down sector.

[0009] In addition, preferably, the inner arc roller and the outer arc roller of the heavy press-down sector are both composed of transmission rollers.

[0010] In addition, preferably, the inner arc roller of the heavy press-down sector is composed of an inner arc non-transmission roller and the inner arc transmission roller; wherein the inner arc non-transmission roller is a segmented roller.

[0011] In addition, preferably, the execution press-down amount of the inner arc non-transmission roller is less than or equal to 3mm; and the execution press-down amount of the inner arc transmission roller is greater than or equal to 5mm.

[0012] In addition, preferably, the outer arc roller of the heavy press-down sector is composed of an outer arc non-transmission roller and the outer arc transmission roller; wherein the outer arc non-transmission roller is a segmented roller.

[0013] In addition, preferably, the roll spacing between the inner arc non-transmission rollers is less than or equal to 400mm; and / or, the roll spacing between the outer arc non-transmission rollers is less than or equal to 400mm.

[0014] In addition, preferably, the length of the segmented part of the inner arc non-transmission roller is greater than 0 and less than or equal to 150mm; and / or, the length of the segmented part of the outer arc non-transmission roller is greater than 0 and less than or equal to 150mm.

[0015] In addition, preferably, the roll diameter of the inner arc transmission roller is equal to the roll diameter of the outer arc transmission roller.

[0016] In addition, preferably, the roll diameter of the inner arc transmission roller is greater than the roll diameter of the outer arc transmission roller.

[0017] In addition, it is preferred that the number of the inner arc transmission rollers is equal to or greater than the number of the outer arc transmission rollers.

[0018] From the above technical solutions, the design method of the slab heavy press-down fan-shaped section provided by the application can ensure that the stable production condition is avoided due to the indentation and the like during the implementation of the heavy press-down process of the equipment scheme with the increased press-down point, the inner arc transmission roller is used for the heavy press-down operation, and a press-down amount of more than 20 mm can be achieved, that is, the stability of the slab drawing is ensured, and the heavy press-down with a large deformation amount can be realized, the flow of the residual molten steel in the slab is effectively promoted, the density is improved, and the internal organization uniformity of the slab is improved; each fan-shaped section can be arranged with at least two heavy press-down rollers (inner arc transmission rollers) driven by a belt, which is beneficial to the stability of the heavy press-down process effect, meets the heavy press-down needs of different drawing speeds and different sections, and effectively implements the slab heavy press-down technology. In particular for wide and thick plates, the heavy press-down technical advantage target of reducing the rolling ratio, reducing the production cost and improving the production efficiency can be realized.

[0019] To the accomplishment of the foregoing and related ends, the application, or one or more aspects thereof, include the features hereinafter fully described and pointed out in the following claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the application. These aspects are indicative, however, of but a few of the various ways in which the principles of the application can be employed. Other objects, advantages, and novel features of the application will become apparent from the following detailed description when considered in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] Other objects and results of the application will become more fully understood and appreciated only upon consideration of the following detailed description, taken in conjunction with the accompanying drawings.

[0021] Figure 1 Flow chart of the design method of the slab heavy press-down fan-shaped section according to the embodiment of the application; Figure 2 Schematic diagram of the design method of the slab heavy press-down fan-shaped section according to the embodiment 1 of the application; Figure 3 Schematic diagram of the design method of the slab heavy press-down fan-shaped section according to the embodiment 2 of the application; Figure 4 Schematic diagram of the design method of the slab heavy press-down fan-shaped section according to the embodiment 3 of the application; Figure 5 Schematic diagram of the design method of the slab heavy press-down fan-shaped section according to the embodiment 4 of the application. DETAILED DESCRIPTION

[0022] In the following description, for the purposes of providing a thorough understanding of one or more embodiments, numerous specific details are set forth in order to provide a broader understanding of the present application. It will be apparent, however, that the present application can be practiced without these specific details.

[0023] In view of the foregoing, the prior art slab heavy press-down fan-shaped segment design scheme has the problems of few press-down points and indentation, which cannot meet the stable production of slab heavy press-down. The present application provides a slab heavy press-down fan-shaped segment design method.

[0024] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0025] To illustrate the slab heavy press-down fan-shaped segment design method provided by the present application, Figure 1 The flowchart of the slab heavy press-down fan-shaped segment design method according to an embodiment of the present application is shown; Figure 2 The slab heavy press-down fan-shaped segment design method according to embodiment 1 of the present application is shown; Figure 3 The slab heavy press-down fan-shaped segment design method according to embodiment 2 of the present application is shown; Figure 4 The slab heavy press-down fan-shaped segment design method according to embodiment 3 of the present application is shown; Figure 5 The slab heavy press-down fan-shaped segment design method according to embodiment 4 of the present application is shown.

[0026] As Figure 1 The slab heavy press-down fan-shaped segment design method provided by the present application mainly includes the following steps: Step S1, at least two transmission rollers are arranged on the inner arc and the outer arc of the heavy press-down fan-shaped segment.

[0027] Specifically, at least two transmission rollers are arranged on the inner arc of the heavy press-down fan-shaped segment of the slab; at least two transmission rollers are also arranged on the outer arc of the heavy press-down fan-shaped segment of the slab, so that each heavy press-down fan-shaped segment is arranged with at least two heavy press-down rollers with transmission, thereby facilitating the stability of the heavy press-down process effect to meet the needs of different rolling speeds and different cross-section heavy press-down.

[0028] Step S2, the transmission rollers arranged on the inner arc are used as inner arc transmission rollers, and the inner arc transmission rollers adopt integral rollers; the transmission rollers arranged on the outer arc are used as outer arc transmission rollers, and the outer arc transmission rollers adopt sectional rollers; wherein the roll diameter of the inner arc transmission rollers is 250mm-450mm; the length of the sectional part of the outer arc transmission rollers is greater than 0 and less than or equal to 150mm.

[0029] Specifically, the inner arc transmission roller adopts a whole roller, and is not divided into sections, so that the inner arc transmission roller can avoid generating a pressure mark when a large pressure is applied, to ensure the realization effect of the slab under heavy pressure. The diameter of the inner arc transmission roller and the length of the section of the outer arc transmission roller are limited, so that the situation of unstable production caused by pressure marks and the like can be avoided during the implementation of the heavy pressure process of the equipment scheme with the increased pressure point. The length of the section of the outer arc transmission roller is not 0 and is less than or equal to 150 mm.

[0030] In step S3, the inner arc roller of the heavy pressure segment is taken as a pressure execution roller, and the inner arc transmission roller is taken as an execution roller of single-roller heavy pressure, to complete the design of the heavy pressure segment.

[0031] Specifically, the inner arc roller of the heavy pressure segment is taken as a pressure execution roller, that is, each inner arc roller in the heavy pressure segment is provided with an independent mechanism and capacity for executing pressure, and whether each inner arc roller executes independent pressure can be determined according to actual needs. The inner arc transmission roller is taken as an execution roller of single-roller heavy pressure, that is, the main heavy pressure is executed by the inner arc transmission roller. The single roller can reach a pressure of more than 20 mm through the heavy pressure operation of the inner arc transmission roller, which can ensure the stability of the slab and realize the deformation pressure, effectively promote the flow of residual molten steel in the slab, improve the density, and improve the uniformity of the internal organization of the slab. The inner arc roller of the heavy pressure segment includes the inner arc transmission roller.

[0032] The heavy pressure segment provided by the present application can be arranged before the solidification end of the slab (a section with a bulging trend), to meet the needs of single-roller heavy pressure, while ensuring that no pressure marks and scratches are generated and the stability of production is ensured.

[0033] At least two inner arc transmission rollers and at least two outer arc transmission rollers are arranged in the heavy pressure segment, the inner arc transmission roller adopts a whole roller, the outer arc transmission roller adopts a sectional roller, and the diameter of the inner arc transmission roller and the length of the section of the outer arc transmission roller are limited, so that the situation of unstable production caused by pressure marks and the like can be avoided during the implementation of the heavy pressure process of the equipment scheme with the increased pressure point. When the inner arc transmission roller is used for heavy pressure operation, a pressure of more than 20 mm can be reached, that is, the stability of the slab can be ensured, and large deformation pressure can be realized, effectively promoting the flow of residual molten steel in the slab, improving the density, and improving the uniformity of the internal organization of the slab. At least two heavy pressure rollers (inner arc transmission rollers) with transmission can be arranged in each segment, which is conducive to the stability of the heavy pressure process effect, meets the needs of heavy pressure at different drawing speeds and different sections, and effectively implements the slab heavy pressure technology. Especially for wide and thick plates, the heavy pressure technology advantage target of reducing the rolling ratio, reducing the production cost, and improving the production efficiency can be realized.

[0034] As a preferred scheme of the present application, the inner arc roller and the outer arc roller of the heavy pressure segment are composed of transmission rollers.

[0035] Specifically, the rollers arranged on the inner arc of the heavy pressing down segment (inner arc rollers) are all driving rollers; the rollers arranged on the outer arc of the heavy pressing down segment (outer arc rollers) are all driving rollers. That is, the whole heavy pressing down segment adopts the combination mode of driving rollers, for example, one heavy pressing down segment adopts the combination mode of four pairs of driving rollers, the inner arc rollers adopt integral rollers, and the outer arc adopts sectional rollers.

[0036] As a preferred scheme of the present application, the inner arc rollers of the heavy pressing down segment are composed of inner arc non-driving rollers and inner arc driving rollers; wherein the inner arc non-driving rollers are sectional rollers.

[0037] Specifically, the rollers arranged on the inner arc of the heavy pressing down segment (inner arc rollers) are composed of inner arc non-driving rollers and inner arc driving rollers, wherein the inner arc non-driving rollers are sectional rollers. That is, in the design method of the heavy pressing down segment of the present application, the inner arc rollers of the heavy pressing down segment can be all inner arc driving rollers, or can be composed of inner arc non-driving rollers and inner arc driving rollers.

[0038] As a preferred scheme of the present application, the execution reduction of the inner arc non-driving rollers is less than or equal to 3mm; and the execution reduction of the inner arc driving rollers is greater than or equal to 5mm.

[0039] Specifically, when the inner arc rollers of the heavy pressing down segment are composed of inner arc non-driving rollers and inner arc driving rollers, the inner arc driving rollers mainly execute large reduction, and the inner arc non-driving rollers execute small reduction, so as to avoid the generation of indentation.

[0040] As a preferred scheme of the present application, the outer arc rollers of the heavy pressing down segment are composed of outer arc non-driving rollers and outer arc driving rollers; wherein the outer arc non-driving rollers are sectional rollers.

[0041] Specifically, the rollers arranged on the outer arc of the heavy pressing down segment (outer arc rollers) are composed of outer arc non-driving rollers and outer arc driving rollers, wherein the outer arc non-driving rollers and the outer arc driving rollers are all sectional rollers. That is, in the design method of the heavy pressing down segment of the present application, the outer arc rollers of the heavy pressing down segment can be all outer arc driving rollers, or can be composed of outer arc non-driving rollers and outer arc driving rollers.

[0042] As a preferred scheme of the present application, the roller spacing between the inner arc non-driving rollers is less than or equal to 400mm; and / or, the roller spacing between the outer arc non-driving rollers is less than or equal to 400mm.

[0043] As a preferred scheme of the present application, the length of the section of the inner arc non-driving rollers is greater than 0, and less than or equal to 150mm; and / or, the length of the section of the outer arc non-driving rollers is greater than 0, and less than or equal to 150mm.

[0044] Specifically, the heavy press-down fan-shaped section can significantly improve the press-down precision and frame bearing capacity by adopting the combined design of non-driven rollers and driven rollers and setting reasonable roller spacing, effectively solves the problems of low precision and insufficient frame bearing capacity in the prior art, thereby realizing the heavy press-down effect of the slab (especially the wide and thick slab); the outer-arc non-driven rollers and the outer-arc driven rollers are all segmented rollers, which can ensure the reduction of the roller diameter, is conducive to the reduction of the roller spacing, reduces the bulging deformation, and is also conducive to the discharge of iron oxide scale, the elimination of pressure marks and scratches, and the guarantee of the surface quality of the slab.

[0045] As a preferred scheme of the present application, the roller diameter of the inner-arc driven roller is equal to the roller diameter of the outer-arc driven roller.

[0046] It should be noted that the roller diameter of the inner-arc driven roller is equal to the roller diameter of the outer-arc driven roller as a preferred scheme of the present application, but the present application does not make special limitation thereon.

[0047] As a preferred scheme of the present application, the roller diameter of the inner-arc driven roller is greater than the roller diameter of the outer-arc driven roller.

[0048] It should be noted that the roller diameter of the inner-arc driven roller is greater than the roller diameter of the outer-arc driven roller as a preferred scheme of the present application, but the present application does not make special limitation thereon.

[0049] As a preferred scheme of the present application, the number of the inner-arc driven rollers is equal to or greater than the number of the outer-arc driven rollers.

[0050] Specifically, the number of the inner-arc driven rollers can be equal to or not equal to the number of the outer-arc driven rollers, which can be determined according to the actual situation, and the present application does not make special limitation thereon.

[0051] In order to better illustrate the application of the design method of the slab heavy press-down fan-shaped section provided by the present application, the following specific embodiments are carried out: Embodiment 1 As Figure 2As shown, under heavy pressure, five rollers are arranged on both the inner and outer arcs of the sector section, forming five pairs of perfectly corresponding pressing roller combinations. Each pair of rollers can achieve independent pressing. The non-drive rollers have a diameter of 350mm and are all four-segment rollers with a gap of 150mm at the segmentation. The distance between two adjacent non-drive rollers is 370mm. The belt-driven rollers have a diameter of 450mm. The inner arc belt-driven roller (inner arc drive roller) is a solid roller, while the outer arc belt-driven roller (outer arc drive roller) is a segmented roller, using four-segment rollers with a gap of 150mm at the segmentation. The inner arc rollers have a pressing mechanism to achieve the pressing action. Each inner arc roller can achieve independent pressing. The inner arc non-drive rollers perform a pressing amount of 2mm, while the inner arc belt-driven solid roller (inner arc drive roller) can achieve a maximum single-roller pressing amount of over 30mm. The drawing is performed by four belt-driven rollers (inner arc drive roller and outer arc drive roller) on the inner and outer arcs.

[0052] Example 2 like Figure 3 As shown, under heavy pressure, five rollers are arranged on both the inner and outer arcs of the sector segment, forming five pairs of perfectly corresponding pressing roller combinations. Each pair of rollers can achieve independent pressing. The non-drive rollers have a diameter of 350mm and are all four-segment rollers with a gap of 150mm at the segmentation. The distance between two adjacent non-drive rollers is 370mm. The inner arc belt-driven roller (inner arc drive roller) has a diameter of 450mm, and the outer arc belt-driven roller (outer arc drive roller) has a diameter of 350mm. The inner arc belt-driven roller (inner arc drive roller) is a solid roller, while the outer arc belt-driven roller (outer arc drive roller) is a segmented roller, using four-segment rollers with a gap of 150mm at the segmentation. The inner arc rollers are all equipped with pressing mechanisms to achieve the pressing action. Each inner arc roller can achieve independent pressing. The inner arc non-drive rollers perform a pressing amount of 2mm, while the inner arc belt-driven solid roller (inner arc drive roller) can achieve a maximum single-roller pressing amount of over 30mm. The drawing process is performed by four belt-driven rollers (inner arc drive roller and outer arc drive roller) on the inner and outer arcs.

[0053] Example 3 like Figure 4As shown in the figure, six rollers are arranged on the inner arc of the heavy press-down fan-shaped segment, and seven rollers are arranged on the outer arc of the heavy press-down fan-shaped segment. The upper and lower rollers do not completely correspond. The roller diameter of the non-driven roller is 350 mm, and all are four-section rollers. The gap spacing at the section is 150 mm, and the spacing between two adjacent non-driven rollers is 370 mm. The roller diameter of the inner arc driven roller (inner arc driven roller) is 450 mm, and the roller diameter of the outer arc driven roller (outer arc driven roller) is 350 mm. The inner arc driven roller (inner arc driven roller) is a whole roller, and the outer arc driven roller (outer arc driven roller) is a section roller. Four-section rollers are adopted, and the gap spacing at the section is 150 mm. The inner arc rollers are all provided with a press-down mechanism to realize the press-down action. Each inner arc roller can realize independent press-down. The press-down amount of the inner arc non-driven roller is 2 mm, and the maximum single-roller press-down amount of the inner arc driven whole roller (inner arc driven roller) is more than 30 mm. The blank drawing is performed by the five driven rollers (inner arc driven roller and outer arc driven roller) on the inner and outer arcs. In order to improve the drawing capacity, the number of drawing rollers is increased on the outer arc.

[0054] It should be noted that the above three embodiments (Embodiment 1-Embodiment 3) are not all forms of the design method of the slab heavy press-down fan-shaped segment proposed by the present application. As long as the arrangement form meets the requirements of the present application, it is within the protection scope of the present application. For example, the roller diameter of the inner arc driven roller is equal to the roller diameter of the inner arc non-driven roller. As long as the inner arc roller can independently perform press-down, the inner arc driven roller performs heavy press-down, and the inner arc driven roller is a whole roller. For another example, the heavy press-down fan-shaped segment can be completely combined with driven rollers. The above embodiments only give an example that the inner arc of the heavy press-down fan-shaped segment has two inner arc driven rollers to perform large press-down. However, the number of inner arc driven rollers can be increased infinitely under the condition that the equipment arrangement allows, so as to increase the point position of performing large press-down.

[0055] Embodiment 4 Taking a 350*2600 mm wide and thick plate caster of a certain steel plant as an example, the steel grade is Q345D, the drawing speed is 0.7 m / min, and two fan-shaped segments designed according to the design method of the slab heavy press-down fan-shaped segment proposed by the present application are arranged at the 11th and 12th segments, as shown in the figure. Figure 5 As shown in the figure, three heavy press-down processes are adopted. Press-down process 1: Each roller performs press-down. The non-driven roller only performs 1 mm press-down, which is equivalent to following and eliminating rebound. Each driven roller performs 9 mm press-down, realizing a total press-down of 21 mm.

[0056] Press-down process 2: The non-driven roller does not perform press-down to eliminate the drawing resistance brought by the non-driven roller as much as possible. Each driven roller performs a single-roller press-down of 15 mm, realizing a total press-down of 30 mm.

[0057] Press-down process 3: According to the solidification process, only the 3# roll with belt drive is used to perform 25mm press-down, and the heavy press-down process idea of performing sufficient press-down at the key position is realized to achieve single roll 25mm press-down amount.

[0058] At the drawing speed of 0.7m / min, the solidification end is located after the 5# roll of the 11th segment and before the 1# roll of the 12th segment, the change of the center solid phase rate, and the press-down amount of the above-mentioned three heavy press-down processes are shown in Table 1. Table 1 As shown in Table 1, the position of performing single roll 25mm press-down is the center solid phase rate 0.6, which is due to the control of the roll spacing, so that the bulging in the un-solidified state of the casting blank is controlled, and therefore the heavy press-down roll can be arranged before the un-solidification, solving the problem that in the prior art, due to the large roll spacing, the heavy press-down roll with a large roll diameter can only be arranged in the late solidification and after the solidification, which is also the reason why the heavy press-down with a large roll diameter in the prior art can only be performed after the center solid phase rate 0.75.

[0059] As can be seen from the above specific embodiments, the design method of the slab heavy press-down fan-shaped segment provided by the present application arranges at least two inner arc transmission rolls and at least two outer arc transmission rolls in the heavy press-down fan-shaped segment, the inner arc transmission roll adopts a whole roll, the outer arc transmission roll adopts a segmented roll, and the roll diameter of the inner arc transmission roll and the length of the segmented part of the outer arc transmission roll are limited, so as to ensure that in the equipment scheme of increasing the press-down point, the heavy press-down process is implemented, and the situation of unstable production caused by indentation and the like is avoided. When the inner arc transmission roll is used for heavy press-down operation, a press-down amount of 20mm or more can be achieved, that is, the stability of the drawing blank is ensured, and a large deformation amount press-down can also be realized, effectively promoting the flow of residual molten steel in the casting blank, improving the density, and improving the internal organization uniformity of the casting blank. Each fan-shaped segment can be arranged with at least two heavy press-down rolls (inner arc transmission rolls) driven by belts, which is conducive to the stability of the heavy press-down process effect, meets the needs of heavy press-down at different drawing speeds and different sections, and effectively implements the slab heavy press-down technology. Especially for wide and thick plates, the heavy press-down technical advantage target of reducing the rolling ratio, reducing the production cost, and improving the production efficiency can be realized.

[0060] The design method of the slab heavy press-down fan-shaped segment according to the present application is described above with reference to the accompanying drawings in an exemplary manner. However, those skilled in the art should understand that various improvements can be made to the above-mentioned design method of the slab heavy press-down fan-shaped segment according to the present application without departing from the content of the present application. Therefore, the protection scope of the present application should be determined by the content of the appended claims.

Claims

1. A method of designing a fan-shaped segment of a slab press-down, characterized by, The method comprises the following steps: At least two transmission rollers are arranged on the inner arc and the outer arc of the heavy reduction fan-shaped segment respectively under heavy pressure; The transmission roller arranged on the inner arc is used as an inner arc transmission roller, and the inner arc transmission roller is a whole roller; The transmission roller arranged on the outer arc is used as an outer arc transmission roller, and the outer arc transmission roller is a segmented roller; wherein the roll diameter of the inner arc transmission roller is 250mm-450mm; the length of the segmented part of the outer arc transmission roller is greater than 0 and less than or equal to 150mm; The inner arc roller of the heavy reduction fan-shaped segment is used as a reduction execution roller, and the inner arc transmission roller is used as a single roller reduction execution roller to complete the design of the heavy reduction fan-shaped segment.

2. The method of designing a fan-shaped segment of slab pass according to claim 1, characterized in that, The inner arc roller and the outer arc roller of the heavy reduction fan-shaped segment are both composed of transmission rollers.

3. The method of designing a fan-shaped segment of slab pass according to claim 1, characterized in that, The inner arc roller of the heavy reduction fan-shaped segment is composed of an inner arc non-transmission roller and the inner arc transmission roller; wherein the inner arc non-transmission roller is a segmented roller.

4. The design method of the slab heavy reduction fan-shaped segment according to claim 3, wherein, The execution reduction amount of the inner arc non-transmission roller is less than or equal to 3mm; The execution reduction amount of the inner arc transmission roller is greater than or equal to 5mm.

5. The method of designing a fan-shaped segment of slab pass according to claim 3, wherein The outer arc roller of the heavy reduction fan-shaped segment is composed of an outer arc non-transmission roller and the outer arc transmission roller; wherein the outer arc non-transmission roller is a segmented roller.

6. The design method of the slab heavy reduction fan-shaped segment according to claim 5, wherein, The roll spacing between the inner arc non-transmission rollers is less than or equal to 400mm; and / or, The roll spacing between the outer arc non-transmission rollers is less than or equal to 400mm.

7. The design method of the slab heavy reduction fan-shaped segment according to claim 5, wherein, The length of the segmented part of the inner arc non-transmission roller is greater than 0 and less than or equal to 150mm; and / or, The length of the segmented part of the outer arc non-transmission roller is greater than 0 and less than or equal to 150mm.

8. The method of designing a fan-shaped segment of a slab press-down according to claim 1, characterized in that, The roll diameter of the inner arc transmission roller is equal to the roll diameter of the outer arc transmission roller.

9. The method of designing a fan-shaped segment of a slab press-down according to claim 1, characterized in that, The roll diameter of the inner arc transmission roller is greater than the roll diameter of the outer arc transmission roller.

10. The method of designing a fan-shaped segment of a slab press-down according to claim 1, characterized in that, The number of the inner arc transmission rollers is equal to or greater than the number of the outer arc transmission rollers.

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