Continuous casting slab narrow face pre-concave process and edge crack control method
The problem of edge crack defects on wide and thick plates was solved by using the chamfered crystallizer and the pre-concave side pressing process of the vertical roller mill, thereby improving the yield rate and reducing production costs.
Patent Information
- Application Number
- CN202510882297.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-17
AI Technical Summary
During the production of wide and thick plates, edge crack defects of 45 to 120 mm often appear on the edges, resulting in a lower yield rate and increased production costs.
A chamfered crystallizer is used to produce continuous casting billets, and after heating and dephosphorization, a vertical roller mill is used to perform pre-concave side pressure. Through multiple passes of vertical roller side pressure and dynamic adjustment of the side pressure reduction, the continuous casting process and continuous rolling process are coordinated and controlled to reduce the side flattening amount and avoid crack defects.
The yield of the plate is improved, crack defects caused by side flattening are avoided, and production costs are reduced.
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Figure CN120790866A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of steel plate manufacturing, and particularly relates to a continuous casting billet narrow surface pre-concave process and edge crack control method. BACKGROUND
[0002] Wide and thick plates are widely applied in the fields of energy and petrochemical industry, building and bridge, transportation, marine ship, etc., and are main raw materials for supporting infrastructure construction. However, in the production process of the wide and thick plates, edge line cracks with a length of 45-120 mm often appear in the edge. In order to ensure the product quality, the edge line crack area is usually cut off, which greatly reduces the yield of the wide and thick plates. Meanwhile, in order to produce the wide and thick plates with a target width, the rolling spread of the steel plate has to be increased, which increases the load of the rolling mill and the production cost.
[0003] As to the mechanism of the edge crack defect, there are mainly the following types:
[0004] First, intermediate billet side surface fold + corner metal overturning: the plastic deformation of the intermediate billet side surface crystal has anisotropy, in the process of flat rolling and continuous pressing, the drum-shaped expansion of the billet side surface metal occurs, so that the corner metal of the billet is continuously overturned upward, and finally the edge line defect is formed. The principle is shown in Figure 1 and Figure 2 .
[0005] Second, uneven deformation: in the hot rolling process, when the temperature of the corner of the intermediate billet is lower than Ar3, the γ-α phase change occurs in the corner, and the relationship between the temperature and the flow stress is shown in Figure 3 . It can be seen that when the temperature is lower than Ar3, the flow stress begins to decrease with the decrease of the temperature; when the temperature reaches Ar1, the flow stress begins to gradually increase with the decrease of the temperature. Therefore, the flow stress of the metal near the Ar3 temperature is obviously higher than that of the adjacent temperature. This makes it difficult for the metal of the corner at the Ar3 temperature to deform in the hot rolling process, so that the transverse spread deformation in the thickness direction is not the same, and the fold appears on the side surface during the flat roller pressing. With the progress of the rolling process, the fold is flattened, and finally the surface crack is formed. The principle is shown in Figure 4 .
[0006] Based on the above-mentioned mechanism of the formation of the edge crack defect, the edge crack defect needs to be improved. SUMMARY
[0007] In view of the problems in the prior art, the present application provides a continuous casting billet narrow surface pre-concave process and edge crack control method, which can coordinate and control the continuous casting process and the continuous rolling process, reduce the side surface overturning amount, and improve the plate yield.
[0008] To solve the above technical problems, the present application provides the following technical solutions:
[0009] The application provides a continuous casting billet narrow surface pre-concave process and an edge crack control method, which comprises the following steps:
[0010] The continuous casting billet is produced by using a chamfered crystallizer; wherein the continuous casting billet produced by the chamfered crystallizer has chamfers at the corners;
[0011] After the heating and dephosphorization process, the continuous casting billet is pre-concaved and pressed by using a vertical roll mill; wherein the vertical roll mill comprises a plurality of vertical rolls; the vertical rolls have a structure of thick in the middle and thin at both ends, and the relationship between the vertical roll radius and the vertical roll length is represented by a polynomial function, a trigonometric function or a normal distribution function.
[0012] Further, the continuous casting billet produced by the chamfered crystallizer has chamfers on both the wide surface and the narrow surface.
[0013] Further, the continuous casting billet produced by the chamfered crystallizer has chamfers only on the wide surface.
[0014] Further, the continuous casting billet produced by the chamfered crystallizer has chamfers only on the narrow surface.
[0015] Further, the chamfered crystallizer comprises a narrow surface area and a wide surface area; wherein the narrow surface area comprises two symmetrically arranged narrow surface chamfered areas; and the length of each narrow surface chamfer accounts for 5% to 25% of the length of the narrow surface.
[0016] Further, the wide surface area comprises two symmetrically arranged wide surface chamfered areas and two symmetrically arranged narrow surface assembly areas; wherein the length of each wide surface chamfer accounts for 2% to 35% of the length of the wide surface.
[0017] Further, after the pre-concave pressing process, the continuous casting billet is sequentially subjected to rough rolling, swing shearing, dephosphorization, finishing rolling, pre-straightening, cooling and hot straightening.
[0018] Further, the number of vertical rolls of the vertical roll mill is 1 to 9; and the number of passes of the pre-concave pressing process is 1 to 9.
[0019] Further, the continuous casting billet is subjected to multiple-pass vertical roll side pressing by using the vertical roll mill; wherein the difference between the length and the radius of the vertical roll used for the first-pass vertical roll side pressing is the smallest; and the difference between the length and the radius of the vertical roll gradually increases with the increase of the number of passes.
[0020] Further, the distance between each vertical roll is independently adjusted to adapt to different rolling processes and slab materials.
[0021] Further, the length of the working surface of the vertical roll is 10 mm to 50 mm larger than the maximum thickness of the continuous casting billet.
[0022] Further, the length of the working surface of the vertical roll is 10 mm to 200 mm smaller than the minimum thickness of the continuous casting billet.
[0023] Further, the vertical roll diameter is less than the vertical roll working surface radius; wherein the vertical roll diameter is 20mm-100mm less than the minimum vertical roll working surface radius.
[0024] Further, the vertical roll working surface length increases with the increase of the pass number.
[0025] Further, the side reduction is dynamically adjusted during the pre-concave side pressing; wherein the side reduction is large when the head of the continuous casting billet is pre-concave side pressed; the side reduction gradually decreases to a set minimum value during the process of the continuous casting billet through the vertical roll mill, so as to perform stable side pressing; the side reduction gradually increases until the continuous casting billet is completely passed through when the tail of the continuous casting billet is pre-concave side pressed.
[0026] In view of the problems in the prior art, the continuous casting billet narrow face pre-concave process and edge crack control method provided by the present application pre-concave side presses the side face of the continuous casting billet before the rolling process, avoids the phenomenon of uneven deformation of the continuous casting billet with thick middle part and thin side face, and at the same time causes the side face to be concave, so as to compensate for the folding of the side face in the rolling process and avoid the crack defects caused by the folding of the side face; the chamfered crystallizer used by the present application has a certain convexity at the edge position of the wide face and the narrow face, so as to avoid the angle crack defects caused by the excessive temperature of the angle part and the core part during the solidification process of the continuous casting billet; the pre-concave side pressing process used by the present application can realize the pressing strategy of large side reduction of the head of the slab and small side reduction of the middle part through the dynamic adjustment of the concave reduction amount of the side face of the slab, improve the phenomenon of wide head and tail of the slab after rolling, and improve the yield. BRIEF DESCRIPTION OF DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0028] Figure 1 It is a schematic diagram of the side face folding and edge defect formation mechanism in the prior art;
[0029] Figure 2 It is a schematic diagram of the folding turning mechanism in the prior art;
[0030] Figure 3 It is a schematic diagram of the relationship between the processing temperature and the flow stress in the prior art;
[0031] Figure 4 It is a schematic diagram of the folding formation mechanism caused by phase change in the prior art;
[0032] Figure 5 The narrow surface pre-concave process and edge crack control method of the continuous casting slab in the embodiment of the present application are as follows:
[0033] Figure 6 Schematic diagram of the production process of hot-rolled strip steel using the pre-concave process in the embodiment of the present application;
[0034] Figure 7 Schematic diagram of a crystallizer with chamfered structure in which both the wide side and the narrow side are chamfered in the embodiment of the present application;
[0035] Figure 8 Schematic diagram of a crystallizer with chamfered narrow sides in an embodiment of the present application;
[0036] Figure 9 Schematic diagram of a crystallizer with a chamfered structure on the wide side in the embodiment of the present application;
[0037] Figure 10 Schematic diagram of the narrow chamfered crystallizer structure in the embodiment of the present application;
[0038] Figure 11 Schematic diagram of the wide-face chamfered crystallizer structure in the embodiment of the present application;
[0039] Figure 12 One of the top views of the arrangement of the vertical roller mill in the embodiment of the present application;
[0040] Figure 13 A schematic diagram comparing the working surface dimensions of the vertical rollers at each pass in the embodiment of the present application;
[0041] Figure 14 Schematic diagram of the side pressure structure of the long vertical roller working surface in the embodiment of the present application;
[0042] Figure 15 Schematic diagram of the side pressure structure of the working surface of the short vertical roller in the embodiment of the present application;
[0043] Figure 16 Schematic diagram of the change of lateral pressure with slab position in the embodiment of the present application;
[0044] Figure 17 Schematic diagram of the change of the longitudinal section of the slab in the embodiment of the present application;
[0045] Figure 18 Schematic diagram of the production process of medium and thick plates using the pre-concave process in the embodiment of the present application;
[0046] Figure 19 Schematic diagram comparing the working surface dimensions of the vertical rollers at each pass in the embodiment of the present application;
[0047] Figure 20 The second top view of the vertical roller mill arrangement in the embodiment of the present application. DETAILED DESCRIPTION
[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.
[0049] In an embodiment, referring to Figure 5 、 Figure 6 In order to be able to coordinate control through the continuous casting process and the continuous rolling process, reduce the side flatness, and improve the plate yield, the present application provides a continuous casting billet narrow surface pre-concave process and edge crack control method, comprising:
[0050] S101: producing a continuous casting billet using a chamfered crystallizer; wherein the continuous casting billet produced by the chamfered crystallizer has a chamfer at the corner;
[0051] S102: after the heating and dephosphorization process, using a vertical roll mill 5 to pre-concave the continuous casting billet to achieve edge crack control; wherein the vertical roll mill 5 comprises a plurality of vertical rolls; the vertical roll has a structure of thick in the middle and thin at both ends, and the relationship between the vertical roll radius and the vertical roll length is represented by a polynomial function, a trigonometric function or a normal distribution function.
[0052] S103: after the pre-concave side pressing process, sequentially performing rough rolling, swing cutting, dephosphorization, finishing rolling, pre-straightening, cooling and hot straightening on the continuous casting billet.
[0053] It can be understood that the continuous casting billet narrow surface pre-concave process and edge crack control method provided by the present application uses a chamfered crystallizer to produce a continuous casting billet. After the continuous casting billet is completed by hot charging and hot delivery, it is heated, then it is descaled to remove the surface iron oxide scale, then it is pre-concave side pressed, and finally it is rolled to complete the production of plate strip.
[0054] The continuous casting billet used in the process is a continuous casting billet (also called a continuous casting slab, simply referred to as a slab) with intermediate thickness, thin at both ends, or with a round corner or chamfer at the corner. Before hot rolling, the slab is pre-concave on the side (also called pre-concave side pressing). The vertical roll used in the pre-concave process has a structure of thick in the middle and thin at both ends. The relationship between the vertical roll radius and the vertical roll length can be represented by a polynomial function, a trigonometric function or a normal distribution function, etc. The center of the vertical roll should be aligned with the center of the slab thickness to ensure the symmetry of the upper and lower parts of the slab. The vertical roll side pressing distance should be determined according to factors such as the slab thickness, the finished product thickness, the rolling process and the slab material. Referring to Figure 5The vertical roll device is arranged after the descaling box and before the rough rolling mill. Specifically, the whole system layout can be in sequence: slab caster 1, slab cutting machine 2, heating furnace 3, first descaling machine 4, vertical roll rolling mill 5, rough rolling mill 6, first swing shear 7, second descaling machine 8, finishing rolling mill 9, laminar cooling system 10, second swing shear 11 and coiler 12.
[0055] In one embodiment, referring to Figure 7 The continuous casting billet produced by the chamfered mold has chamfers on both the wide face and the narrow face.
[0056] In one embodiment, referring to Figure 8 The continuous casting billet produced by the chamfered mold has a chamfer only on the narrow face.
[0057] In one embodiment, referring to Figure 9 The continuous casting billet produced by the chamfered mold has a chamfer only on the wide face.
[0058] In one embodiment, referring to Figure 10 The chamfered mold comprises a narrow face region and a wide face region; wherein the narrow face region comprises two symmetrically arranged narrow face chamfer regions; and each narrow face chamfer has a length of 5% to 25% of the length of the narrow face.
[0059] In one embodiment, referring to Figure 11 The wide face region comprises two symmetrically arranged wide face chamfer regions and two symmetrically arranged narrow face assembly regions; and each wide face chamfer has a length of 2% to 35% of the length of the wide face.
[0060] It can be understood that the chamfered mold produces a continuous casting billet with chamfers at the corner positions, which can have chamfers on both the wide face and the narrow face, or only on the narrow face, or only on the wide face, as shown in Figure 7 , Figure 8 and Figure 9 .
[0061] Referring to Figure 10 , the chamfered part of the chamfered mold can be located at the narrow face of the mold. The narrow face region of the mold is divided into a middle region and two side chamfer regions, and each narrow face chamfer has a length of 5% to 25% of the length of the narrow face.
[0062] Referring to Figure 11 , the wide face region of the mold is divided into a middle region, two side chamfer regions and a narrow face assembly region, and each wide face chamfer has a length of 2% to 35% of the length of the wide face.
[0063] In one embodiment, referring to Figure 12 The number of vertical rolls of the vertical roll rolling mill 5 is 1 to 9; and the number of passes of the pre-dishing pressure measurement process is 1 to 9.
[0064] In one embodiment, referring to Figure 13 , the continuous casting billet is subjected to multi-pass vertical roll side pressing by using the vertical roll mill 5; wherein the difference between the length and the radius of the vertical roll used in the first pass of vertical roll side pressing is the smallest; and the difference between the length and the radius of the vertical roll gradually increases with the increase of the pass number.
[0065] In one embodiment, referring to Figure 14 , the distance between each vertical roll is independently adjusted to adapt to different rolling processes and slab materials.
[0066] It can be understood that the number of vertical rolls used in the vertical roll side pressing pre-concave process is 1-9, and the pre-concave process is 1-9 passes of side pressing. When multi-pass vertical roll side pressing is performed, the distance between the two vertical rolls in each pass can be independently adjusted to adapt to different rolling processes and slab materials. When multi-pass vertical roll side pressing is performed, the radius difference between the middle and both ends of the first pass vertical roll is smaller, and the radius difference between the middle and both ends of the vertical roll gradually increases with the increase of the pass number. The length of the working surface of the vertical roll also increases with the increase of the pass number. Referring to Figure 13 , Figure 14 and Figure 15 , the length of the working surface of the vertical roll refers to the roll length (arc length) of the vertical roll.
[0067] In one embodiment, referring to Figure 15 , the length of the working surface of the vertical roll is 10-50 mm larger than the maximum thickness of the continuous casting billet.
[0068] In one embodiment, referring to Figure 15 , the length of the working surface of the vertical roll is 10-200 mm smaller than the minimum thickness of the continuous casting billet.
[0069] In one embodiment, referring to Figure 15 , the roll diameter of the vertical roll is smaller than the radius of the working surface of the vertical roll; wherein the roll diameter of the vertical roll is 20-100 mm smaller than the minimum radius of the working surface of the vertical roll.
[0070] In one embodiment, the length of the working surface of the vertical roll increases with the increase of the pass number.
[0071] It can be understood that the length of the working surface of the vertical roll is the maximum thickness of the slab + (10-50) mm. The length of the working surface of the vertical roll is the minimum thickness of the slab - (10-200) mm, and the roll diameter of the vertical roll is obviously smaller than the radius of the working surface, which can be represented as roll diameter = minimum radius of the working surface - (20-100) mm.
[0072] In one embodiment, referring to Figure 16The side pressing amount is dynamically adjusted during the pre-concave side pressing. The side pressing amount is large when the head of the continuous casting billet is pre-concave side pressed. The side pressing amount gradually decreases to a set minimum value during the process that the continuous casting billet passes through the vertical roller mill 5, so that stable side pressing is performed. The side pressing amount gradually increases until the continuous casting billet completely passes through when the tail of the continuous casting billet is pre-concave side pressed.
[0073] It can be understood that the side pressing amount of the vertical roller side pressing is dynamically adjusted. The adjustment strategy is that the pressing amount of the head of the slab is large, the pressing amount gradually decreases to a set minimum value during the passing process of the slab, and stable side pressing is maintained. When the tail of the slab is about to be reached, the side pressing amount gradually increases until the slab completely passes through.
[0074] Under the process conditions used in the present application, the shape change of the continuous casting billet is shown in Figure 17 . From top to bottom, they are continuous casting billet, continuous casting billet into vertical roller mill 5, continuous casting billet pre-concave process, continuous casting billet complete pre-concave, and continuous casting billet after rolling.
[0075] As can be seen from the above description, the continuous casting billet narrow face pre-concave process and edge crack control method provided by the present application pre-concave side presses the side face of the continuous casting billet before the rolling process, avoids the phenomenon that the continuous casting billet is thick in the middle and thin on the side, and the deformation is uneven, at the same time, the side face is concave, so as to compensate the folding of the side face in the rolling process, and avoid the crack defect caused by the folding of the side face. The chamfered crystallizer used by the present application has a certain protrusion at the edge position of the wide face and the narrow face, which avoids the angle crack defect caused by the excessive temperature of the angle part and the core part during the solidification process of the continuous casting billet. The pre-concave side pressing process used by the present application can dynamically adjust the concave pressing amount of the side face of the slab, realize the pressing strategy that the side pressing amount of the head of the slab is large and the side pressing amount of the middle part is small, improve the phenomenon that the head and tail of the rolled plate are wide, and improve the yield.
[0076] Example 1:
[0077] Referring to Figure 18 , the continuous casting billet narrow face pre-concave process is used to produce a medium plate, and the production process is as follows:
[0078] (1) The chamfered crystallizer is used to produce the continuous casting billet;
[0079] (2) The continuous casting billet is hot charged and hot sent into the heating furnace;
[0080] (3) After being heated to a set temperature, the continuous casting billet is descaled in the descaling machine;
[0081] (4) After descaling, the continuous casting billet is pre-concave in the vertical roller mill unit;
[0082] (5) The continuous casting billet is coarsely rolled in the single-stand rough rolling mill, at this time, the vertical rollers are all released, and the side pressing is not performed again;
[0083] (6) After rough rolling, enter the pre-rolling roller for temperature waiting;
[0084] (7) After subsequent processes such as finish rolling, pre-straightening, cooling, and hot straightening.
[0085] The chamfered crystallizer is composed of a narrow face with a chamfered structure and a wide face without a chamfered structure. The chamfered crystallizer has a width of 2100 mm and a thickness of 230 mm. The narrow face of the chamfered part has a size of 45 mm. The angle between the chamfered area and the middle area of the narrow face is an obtuse angle of 125°. The chamfered continuous casting billet is produced by the above-mentioned chamfered crystallizer. The continuous casting billet is heated to 1300°C and then discharged after holding. After passing through the descaling machine, it enters the edger mill for pre-concave.
[0086] Referring to Table 1, the pre-concave process is divided into 5 passes. The working surface length and radius of the edger mill (see Figure 20 ) are expressed as follows:
[0087] Table 1
[0088]
[0089]
[0090] wherein, referring to Figure 19 , R is the difference between the working surface radius of the edger mill and the standard radius, mm; H is the working surface length of the edger mill (with the center position of the plate thickness as 0), mm; R0 is the standard radius of the working surface of the edger mill, mm.
[0091] The initial position of the distance between the two edger mills of each pass of the pre-concave process is 2100+2R0. The set reduction amount ΔB(i) is 0 mm, 2 mm, 8 mm, 12 mm, and 15 mm, respectively, wherein i is the pass number of the roller, taking 1, 2, 3, 4, and 5.
[0092] When the continuous casting billet passes through the edger mill, the reduction amount is adjusted floatingly. The adjustment changes are as follows: the reduction amount on the head side of the slab is larger, which is ΔB(i)+ΔB T , the side reduction amount gradually decreases to the set minimum value ΔB(i) and remains stable, and when it is about to reach the tail of the slab, the side reduction amount gradually increases to ΔB(i)+ΔB W , until the slab passes completely.
[0093] Example 2:
[0094] The continuous casting billet narrow face pre-concave process is used to produce hot-rolled strip steel, and the production process is as follows:
[0095] (1) Use the chamfered crystallizer to produce continuous casting billets;
[0096] (2) The continuous casting billet is hot charged and hot sent into the heating furnace;
[0097] (3) After heating to the set temperature, the billet is sent into the descaling machine for descaling;
[0098] (4) After descaling, the billet is sent into the edger roller mill unit for pre- concaving;
[0099] (5) The billet is sent into the rough rolling mill unit for rough rolling;
[0100] (6) After the rough rolling is completed, the billet is sent into the pre- descaling machine for descaling;
[0101] (7) Subsequently, the subsequent processes such as finish rolling, cooling, shearing and coiling are performed.
[0102] The chamfered crystallizer is composed of a wide face with a chamfered structure and a narrow face without a chamfered structure. The chamfered crystallizer has a width of 1600 mm and a thickness of 230 mm. The chamfered part has a wide face size of 200 mm. The included angle between the chamfered area and the middle area of the narrow face is an obtuse angle of 100°. The chamfered continuous casting billet is produced by using the above chamfered crystallizer. The continuous casting billet is heated to 1300 °C and then discharged after being kept for a certain time. After passing through the descaling machine, the billet is sent into the edger roller mill for pre- concaving.
[0103] Referring to Table 2, the pre- concaving process is performed in 5 passes. The working surface length of the edger roller (see Figure 20 ) is related to the radius as follows:
[0104] Table 2
[0105]
[0106] wherein R is the difference between the working surface radius of the edger roller and the standard radius, mm; H is the working surface length of the edger roller (with the center position of the plate thickness as 0), mm; and R0 is the standard radius of the working surface of the edger roller, mm.
[0107] The initial position of the distance between the two edger rollers in each pass of the pre- concaving process is 1600+2R0. The set reduction amount ΔB(i) is 0 mm, 11 mm, 22 mm, 41 mm and 50 mm respectively, wherein i is the roller in each pass, taking 1, 2, 3, 4 and 5.
[0108] When the continuous casting billet passes through the edger roller mill, the reduction amount is adjusted floatingly. The adjustment change is that the reduction amount on the head side of the slab is larger, which is ΔB(i)+ΔB T . During the passing of the slab, the side reduction amount gradually decreases to the set minimum value ΔB(i) to keep stable side reduction. When the tail of the slab is about to be reached, the side reduction amount gradually increases to ΔB(i)+ΔB W , until the slab completely passes through.
[0109] The various embodiments in the specification are described in progressive manner, and the same or similar parts between the embodiments can be mutually referred to, and each embodiment focuses on the difference from other embodiments.
[0110] The above describes specific embodiments of the specification. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims can be performed in a different order than the order in which they are recited and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.
[0111] The various embodiments in the specification are described in progressive manner, and the same or similar parts between the embodiments can be mutually referred to, and each embodiment focuses on the difference from other embodiments. In the description of the specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the specification. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.
[0112] The above only describes the embodiments of the embodiments of the specification and does not limit the embodiments of the specification. The embodiments of the specification can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the embodiments of the specification shall be included in the scope of the claims of the embodiments of the specification.
Claims
1. A continuous casting slab narrow surface pre-concave process and edge crack control method, characterized in that: include: A chamfering mold is used to produce a continuous casting billet; wherein the continuous casting billet produced by the chamfering mold has chamfers at the corners; After the continuous casting billet is heated and dephosphorized, the continuous casting billet is pre-concave-pressed by a vertical roller mill; wherein the vertical roller mill includes a plurality of vertical rollers; the vertical rollers are thick in the middle and thin at both ends, and the relationship between the vertical roller radius and the vertical roller length is represented by a polynomial function, a trigonometric function or a normal distribution function.
2. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 1, characterized in that: Both the wide side and the narrow side of the continuous casting billet produced by the chamfering crystallizer are chamfered.
3. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 1, characterized in that: The continuous casting slab produced by the chamfering crystallizer has chamfers on its wide surface.
4. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 1, characterized in that: The continuous casting slab produced by the chamfering mold has chamfers on its narrow side.
5. The narrow surface pre-concave process and edge crack control method of continuous casting slab according to claim 1, characterized in that: The chamfered crystallizer includes a narrow surface area and a wide surface area; wherein the narrow surface area includes two symmetrically arranged narrow surface chamfered areas; the length of each narrow surface chamfer accounts for 5% to 25% of the narrow surface length.
6. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 5, characterized in that: The wide surface area includes two symmetrically arranged wide surface chamfered areas and two symmetrically arranged narrow surface assembly areas; wherein the length of each wide surface chamfer accounts for 2% to 35% of the length of the wide surface.
7. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 1, characterized in that: After the vertical roller mill is used to perform pre-concave side pressing on the continuous casting billet, the method further comprises: The continuous casting billet is subjected to rough rolling, swing shearing, dephosphorization, finish rolling, pre-straightening, cooling and hot straightening in sequence.
8. The narrow surface pre-concave process and edge crack control method of continuous casting slab according to claim 1, characterized in that: The number of vertical rollers of the vertical roller mill is 1 to 9; the number of passes of the pre-concave pressure measuring process is 1 to 9.
9. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: The method of performing pre-concave side pressing on the continuous casting billet by using a vertical roller mill comprises: The vertical roller mill is used to perform multiple passes of vertical roller side pressing on the continuous casting billet; among the vertical rollers used for vertical roller side pressing in each pass, the difference between the length of the vertical roller used for the first pass of vertical roller side pressing and the radius of the vertical roller is the smallest; as the number of passes increases, the difference between the length of the vertical roller and the radius of the vertical roller gradually increases.
10. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: Also includes: The distance between each vertical roller can be adjusted independently to adapt to different rolling processes and slab materials.
11. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: The length of the working surface of the vertical roller is 10 mm to 50 mm greater than the maximum thickness of the continuous casting billet.
12. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: The length of the vertical roller working surface is 10 mm to 200 mm smaller than the minimum thickness of the continuous casting billet.
13. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: The diameter of the vertical roller is smaller than the radius of the working surface of the vertical roller; wherein the diameter of the vertical roller is 20 mm to 100 mm smaller than the minimum radius of the working surface of the vertical roller.
14. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 12, characterized in that: The length of the vertical roller working surface increases with the increase of the number of passes.
15. The narrow surface pre-concave process and edge crack control method of the continuous casting slab according to claim 8, characterized in that: When performing pre-concave side pressure, the side pressure reduction amount is dynamically adjusted; wherein, when performing pre-concave side pressure on the head of the continuous casting billet, the side pressure reduction amount is large; in the process of the continuous casting billet passing through the vertical roller mill, the side pressure reduction amount is gradually reduced to the set minimum value to perform stable side pressure; when performing pre-concave side pressure on the tail of the continuous casting billet, the side pressure reduction amount is gradually increased until the continuous casting billet passes completely.
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CN121423552A