Press roll, withdrawal and straightening machine and square billet processing device

Abstract

According to the pressing rollers, the withdrawal and straightening machine and the square billet machining device, the radial size of a first roller section and the radial size of a third roller section are higher than the roller shape of a second roller section, in the process that the two pressing rollers extrude incompletely-solidified molten steel from the upper direction and the lower direction, the incompletely-solidified molten steel is limited through the first roller section and the third roller section, and therefore the incompletely-solidified molten steel is limited through the first roller section and the third roller section; the axial movement of the incompletely solidified molten steel along the gap between the two screw-down rollers is avoided, so that the deviation of the square billet is avoided, and even if the screw-down rollers play, under the limitation of the first roller section and the third roller section, the square billet can still be ensured not to deviate when being pressed down by the screw-down rollers.

Description

Technical Field

[0001] The invention relates to the technical field of continuous casting of square billets, and in particular to a pressing roller, a straightening machine and a square billet processing device. Background Art

[0002] In the continuous casting billet production process, the incompletely solidified molten steel sent out of the crystallizer is mechanically extruded and shaped by two upper and lower pressing rollers to obtain a billet.

[0003] When the two pressing rollers extrude the incompletely solidified molten steel from the upper and lower directions, the incompletely solidified molten steel tends to move along the gap between the two pressing rollers, thereby causing the billet to deviate. Especially when the pressing rollers are in sync, the billet deviation problem will be aggravated when the pressing rollers are pressed down. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a reduction roller, a tension leveler and a square billet processing device that overcome the above problems or at least partially solve the above problems.

[0005] In a first aspect, a reduction roller is provided for a mechanical reduction process of a continuous casting billet; the reduction roller comprises:

[0006] A first roller segment, a second roller segment, and a third roller segment are sequentially arranged along the axial direction of the pressing roller;

[0007] The radial dimension of the first roller segment is greater than the radial dimension of the second roller segment, and is used to limit one end of the square blank during roll forming;

[0008] The radial dimension of the third roller segment is greater than the radial dimension of the second roller segment, and is used to limit the other end of the square blank during roll forming.

[0009] Optionally, the second roller segment comprises:

[0010] A first sub-roller segment, a second sub-roller segment, and a third sub-roller segment are sequentially arranged along the axial direction of the pressing roller;

[0011] The roller profile curve of the second sub-roller segment is a curve convex radially outward or convex, and the roller profile curve of the second sub-roller segment has a symmetry axis, and the symmetry axis intersects the axis of the pressing roller perpendicularly;

[0012] The radial dimension of the first sub-roller segment is smaller than the radial dimension of the second sub-roller segment;

[0013] The radial dimension of the third sub-roller segment is smaller than the radial dimension of the second sub-roller segment.

[0014] Optionally, the roller profile curve of the first sub-roller segment is a horizontal line or an arc-shaped curve with an opening radially outward;

[0015] The roll profile curve of the third sub-roll section is a horizontal line or an arc curve with an opening radially outward;

[0016] The roll profile curve of the third sub-roll section is symmetric about the axis of symmetry with the roll profile curve of the second sub-roll section, and the roll profile curve of the second sub-roll section has a first high point, and the first high point is located on the axis of symmetry.

[0017] Optionally, the first roll section includes:

[0018] A fourth sub-roll section and a fifth sub-roll section arranged in sequence along the axial direction of the backup roll;

[0019] The roll profile curve of the fourth sub-roll section intersects with the roll profile curve of the first sub-roll section at a first low point, and the radial height of the first low point satisfies the condition: D1 - 0.2T ≤ D2 < D1, where D1 is the radial height of the first high point, T is the preset height of the square billet, and D2 is the radial height of the first low point;

[0020] The roll profile curve of the fifth sub-roll section intersects with the roll profile curve of the fourth sub-roll section at a first transition point, and the radial height of the first transition point is greater than the radial height of the first low point.

[0021] Optionally, the third roll section includes:

[0022] A sixth sub-roll section and a seventh sub-roll section arranged in sequence along the axial direction of the backup roll;

[0023] The roll profile curve of the sixth sub-roll section intersects with the roll profile curve of the third sub-roll section at a second low point, and the radial height of the second low point is less than the radial height of the first high point, and the radial height of the second low point satisfies the condition: D1 - 0.2T < D3 < D1; where D3 is the radial height of the second low point;

[0024] The roll profile curve of the seventh sub-roll section intersects with the roll profile curve of the sixth sub-roll section at a second transition point, and the radial height of the second transition point is greater than the radial height of the second low point.

[0025] Optionally, the axial distance between the second low point and the first low point satisfies the condition 0.1W ≤ L1 ≤ 0.9W, L1 is the axial distance between the second low point and the first low point, and W is the preset width of the square billet; the axial distance between the second transition point and the first transition point satisfies the condition: 1.003W ≤ L2 ≤ 1.03W, and L2 > L1, L2 is the axial distance between the second transition point and the first transition point.

[0026] Optionally, the end point of the roll profile curve of the fifth sub-roll section far from the first transition point is a second high point, and the radial height of the second high point is greater than the radial height of the first transition point;

[0027] The end point of the roll profile curve of the seventh sub-roll section far from the second transition point is a third high point, and the radial height of the third high point is greater than the radial height of the second transition point;

[0028] The axial distance between the third highest point and the second highest point satisfies the condition: L3≥L2, where L3 is the axial distance between the third highest point and the second highest point.

[0029] Optionally, the roller profile curve of the fifth sub-roller segment is a straight line or a curve passing through the second highest point and the first transition point;

[0030] The roll profile curve of the seventh sub-roll segment is a straight line or a curve passing through the third high point and the second transition point.

[0031] In a second aspect, a tensioning and leveling machine is provided, comprising a frame and at least one pressing roller according to the first aspect, wherein the pressing roller is rotatably connected to the frame.

[0032] In a third aspect, a billet processing device is provided, comprising a crystallizer and at least one tension and leveling machine according to the second aspect;

[0033] The crystallizer is used to output the steel billet to be shaped;

[0034] The tension and leveling machine is used to mechanically press the steel billet to be shaped to obtain a square billet.

[0035] The technical solution provided by this application has at least the following technical effects or advantages:

[0036] The reduction roller, straightening machine and square billet processing device provided in the present application adopt a roller shape in which the radial dimensions of the first roll segment and the third roll segment are higher than those of the second roll segment. During the process in which the two reduction rollers extrude the incompletely solidified molten steel from the upper and lower directions, the first roll segment and the third roll segment restrict the incompletely solidified molten steel to prevent the incompletely solidified molten steel from moving axially along the gap between the two reduction rollers, thereby preventing the square billet from running off. Even if the reduction rollers are in tandem, the square billet can still be prevented from running off when the reduction rollers are pressed down under the restriction of the first roll segment and the third roll segment.

[0037] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0039] Figure 1 A cross-sectional view of a pressing roller in an embodiment of the present application;

[0040] Figure 2 This is a structural diagram of a billet processing device in an embodiment of the present application;

[0041] Figure 3 Schematic diagram of the arrangement of the first tensioning and leveling machine pressing rollers in the embodiment of the present application Figure 1 ;

[0042] Figure 4 Schematic diagram of the arrangement of the first tensioning and leveling machine pressing rollers in the embodiment of the present application Figure 2 ;

[0043] Figure 5 Schematic diagram of the arrangement of the pressing rollers of the second tensioning and leveling machine in the embodiment of the present application Figure 1 ;

[0044] Figure 6 Schematic diagram of the arrangement of the pressing rollers of the second tensioning and leveling machine in the embodiment of the present application Figure 2 ;

[0045] Figure 7 It is a schematic diagram of the low-magnification transverse morphology of the unpressed ingot;

[0046] Figure 8 This is a schematic diagram of the low-magnification transverse morphology of the pressed billet;

[0047] Fig. 9 This is a schematic diagram of the low-magnification longitudinal morphology of the unpressed ingot;

[0048] Fig.10 This is a schematic diagram of the low-magnification longitudinal morphology of the pressed billet;

[0049] Fig.11 It is a schematic diagram of the transverse low-power center carbon segregation index of the unpressed cast billet and the pressed cast billet;

[0050] Fig.12 Schematic diagram of the longitudinal low-magnification central carbon segregation index of unpressed ingots and pressed ingots. DETAILED DESCRIPTION

[0051] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0052] Various structural schematic diagrams according to embodiments of the present application are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0053] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in combination with specific implementation methods. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0054] Continuous casting billet is the product obtained by casting molten steel from a steelmaking furnace through a continuous casting machine. It is mainly divided into slab billet, square billet, rectangular billet and round billet in terms of appearance. In the casting process of the continuous casting machine, the defect of loose core is common.

[0055] Taking billets as an example, in order to solve the problem of loose core of continuous casting billets, the common practice is to transform the traditional billet straightening machine into a multi-flight arch-type straightening machine, and combine it with the upgrade of the hydraulic system (pressure upgrade, corresponding equipment upgrade (pump, pipeline), high cost) to improve the equipment's pressing capacity and achieve a large deformation of the billet. Although this method significantly improves the equipment capacity and the process window is wider, the equipment investment is large, with an average investment of about 2 million for a single frame, and the investment for transforming a six-machine six-stream small billet continuous casting machine is 30 to 50 million. On the other hand, the increase in pressing force is accompanied by an aggravation of the problem of billet deviation during the pressing process, so it is difficult to guarantee the quality of the billet.

[0056] In view of this, the present application provides a pressing roller, please refer to Figure 1 , Figure 1 This is a cross-sectional view of a reduction roller in an embodiment of the present application, which is used in a mechanical reduction process for continuous casting billets, including:

[0057] A first roller segment 101, a second roller segment 102, and a third roller segment 103 are sequentially arranged along the axial direction of the pressing roller.

[0058] The radial dimension of the first roller segment 101 is larger than that of the second roller segment 102, and is used to limit one end of the square blank during roll forming. The radial dimension of the third roller segment 103 is larger than that of the second roller segment 102, and is used to limit the other end of the square blank during roll forming.

[0059] The down-pressing roller adopts a roller shape in which the radial dimensions of the first roller segment 101 and the third roller segment 103 are higher than those of the second roller segment 102, forming a convex shape at both axial ends of the down-pressing roller that extends radially by a certain length compared to the roller body axis 105. During the process of the down-pressing roller extruding the incompletely solidified molten steel, the incompletely solidified molten steel is restricted to prevent the axial deviation of the square billet. Even if the down-pressing roller is in sync, under the restriction of the first roller segment 101 and the third roller segment 103, the down-pressing roller can still ensure that the square billet does not deviate when pressing down, and ensure the down-pressing centering.

[0060] In some optional embodiments, Figure 1 As shown, the second roller segment 102 includes:

[0061] A first sub-roller segment 1021, a second sub-roller segment 1022, and a third sub-roller segment 1023 are sequentially arranged along the axial direction of the pressing roller;

[0062] The roller profile curve of the second sub-roller segment 1022 is a curve protruding radially outwards. The roller profile curve of the second sub-roller segment has a symmetry axis 104. The symmetry axis 104 intersects the axis 105 of the pressing roller perpendicularly. The roller profile curve of the second sub-roller segment can be a fixed curvature or a progressive curvature curve protruding radially outwards, or can be a platform curve protruding outwards.

[0063] The radial dimension of the first sub-roller segment 1021 is smaller than the radial dimension of the second sub-roller segment 1022;

[0064] The radial dimension of the third sub-roller segment 1023 is smaller than the radial dimension of the second sub-roller segment 1022 .

[0065] When traditional convex rollers press down the continuous casting billet, the pressing efficiency of large square billet continuous casting can be improved, but the convex rollers will further cause the billet to deviate and deform. In this application, based on the axial restriction of the billet by the first roller segment 101 and the third roller segment 103, the second roller segment 102 adopts a convex roller with a high middle and low ends, which can further improve the pressing efficiency and reduce equipment requirements while ensuring that the billet does not deviate.

[0066] In some optional embodiments, Figure 1 As shown, the roller profile curve of the first sub-roll segment 1021 is a horizontal line or an arc-shaped curve with an opening radially outward; the roller profile curve of the third sub-roll segment 1023 is a horizontal line or an arc-shaped curve with an opening radially outward; the roller profile curve of the third sub-roll segment 1023 is symmetrical to the roller profile curve of the second sub-roll segment 1022 about the symmetry axis 104, and the roller profile curve of the second sub-roll segment 1022 has a first high point 106, and the first high point 106 is located on the symmetry axis 104.

[0067] The first sub-segment 1021, the second sub-segment 1022, and the third sub-segment 1023 constitute the second roll segment 102, and the curvature of the roll profile curve of the first sub-segment 1021, the second sub-segment 1022, and the third sub-segment 1023 can be a fixed value or a gradual value to achieve a smooth transition.

[0068] In some alternative embodiments, the first roll segment 101 includes: a fourth sub-roll segment 1011 and a fifth sub-roll segment 1012 arranged in sequence along the axial direction of the reduction roll. The roll profile curve of the fourth sub-roll segment 1011 intersects the roll profile curve of the first sub-roll segment 1021 at a first low point 107, and the radial height of the first low point 107 satisfies the condition: D1 - 0.2T < D2 < D1, where D1 is the radial height of the first high point 106, T is the preset height of the bloom, and D2 is the radial height of the first low point 107. The roll profile curve of the fifth sub-roll segment 1012 intersects the roll profile curve of the fourth sub-roll segment 1011 at a first transition point 108, and the radial height of the first transition point 108 is greater than the radial height of the first low point 107.

[0069] The roll profile curves of the fourth sub-roll segment 1011 and the fifth sub-roll segment 1012 can be a fixed value or a gradually changing value to achieve a smooth transition. The first low point 107 is located on the roll surface with the smallest radial dimension of the reduction roll, and there is a certain radial height difference between it and the first high point 106, ensuring that the second roll segment 102 is convex with a higher middle and lower ends, so as to ensure the reduction amount and reduction efficiency during the continuous casting of the bloom.

[0070] In some alternative embodiments, the third roll segment 103 includes: a sixth sub-roll segment 1031 and a seventh sub-roll segment 1032 arranged in sequence along the axial direction of the reduction roll. The roll profile curve of the sixth sub-roll segment 1031 intersects the roll profile curve of the third sub-roll segment 1023 at a second low point 109, and the radial height of the second low point 109 is less than the radial height of the first high point 106. The radial height of the second low point 109 satisfies the condition: D1 - 0.2T < D3 < D1; where D3 is the radial height of the second low point 109. The roll profile curve of the seventh sub-roll segment 1032 intersects the roll profile curve of the sixth sub-roll segment 1031 at a second transition point 110, and the radial height of the second transition point 110 is greater than the radial height of the second low point 109.

[0071] Similarly, the roll profile curves of the sixth sub-roll segment 1031 and the seventh sub-roll segment 1032 can be a fixed value or a gradually changing value to achieve a smooth transition. The second low point 109 is located on the roll surface with the smallest radial dimension of the reduction roll, and there is a certain radial height difference between it and the first high point 106, ensuring that the second roll segment 102 is convex with a higher middle and lower ends, so as to ensure the reduction amount and reduction efficiency during the continuous casting of the bloom.

[0072] It can be understood that the roll profile curves of the first roll segment 101 and the third roll segment 103 are symmetric about the axis of symmetry 104, and the second low point 109 and the first low point 107 are symmetric about the axis of symmetry 104, which can ensure the symmetry of the bloom shape.

[0073] In some optional embodiments, the axial distance between the second low point 109 and the first low point 107 satisfies the condition 0.1W≤L1≤0.9W, L1 is the axial distance between the second low point 109 and the first low point 107, and W is a preset billet width; the axial distance between the second transition point 110 and the first transition point 108 satisfies the condition: 1.003W≤L2≤1.03W, and L2>L1, L2 is the axial distance between the second transition point 110 and the first transition point 108.

[0074] The axial distance between the second transition point 110 and the first transition point 108 reflects the axial width of the concave groove formed by the first roll segment 101, the second roll segment 102, and the third roll segment 103. This width will affect the width of the roll-formed square billet, so it needs to be kept within a reasonable range to ensure that the width dimension of the square billet meets the preset requirements.

[0075] In some optional embodiments, the end point of the roller profile curve of the fifth sub-roller segment 1012 away from the first transition point 108 is the second highest point 111, and the radial height of the second highest point 111 is greater than the radial height of the first transition point 108. The end point of the roller profile curve of the seventh sub-roller segment 1032 away from the second transition point 110 is the third highest point 112, and the radial height of the third highest point 112 is greater than the radial height of the second transition point 110. The axial distance between the third highest point 112 and the second highest point 111 satisfies the condition: L3 ≥ L2, wherein L3 is the axial distance between the third highest point 112 and the second highest point 111.

[0076] The axial distance between the third highest point 112 and the second highest point 111 is not less than the axial distance between the second transition point 110 and the first transition point 108, ensuring that the opening of the concave groove formed by the first roll segment 101, the second roll segment 102 and the third roll segment 103 is an expanded type, ensuring that the square billet maintains a reasonable contact state with the pressing roller after mechanical pressing and deformation.

[0077] In some optional embodiments, the roll profile curve of the fifth sub-roller segment 1012 is a straight line or a curve passing through the second highest point 111 and the first transition point 108. The roll profile curve of the seventh sub-roller segment 1032 is a straight line or a curve passing through the third highest point 112 and the second transition point 110. The roll profile curves of the fifth sub-roller segment 1012 and the seventh sub-roller segment 1032 can be arc curves with fixed curvature or gradual curvature to ensure smooth transition between the roll segments.

[0078] Based on the same inventive concept, an embodiment of the present application further provides a tensioning and straightening machine, comprising a frame and at least one pressing roller provided in the above embodiment, wherein the pressing roller is rotatably connected to the frame.

[0079] The drawing and straightening machine provided in the embodiment of the present application can be used for the mechanical pressing process of square billets. The types of drawing and straightening machines include but are not limited to arch type, clamp type, combined type, integral five-roller type, etc. The drawing and straightening machine is used to roll-form square billets.

[0080] The straightening machine provided in the embodiment of the present application is used to mechanically press the steel billet to be shaped under the condition of hot billet pressure range of 4.0-30 MPa. Figure 1 The second roller segment 102 of the reduction roller shown can achieve a reduction of 2.0 to 30.0 mm on the surface of the square billet and ensure that the square billet does not deviate. Compared with the traditional reduction roller of the straight roller curve, the reduction amount of the straightening machine provided in the embodiment of the present application is increased by more than twice.

[0081] The tensioning and leveling machine provided in the embodiment of the present application realizes high pressure reduction efficiency through reasonable design of the roller shape of the reduction roller, solves the problem of deviation during reduction, greatly reduces the investment cost of light / heavy reduction equipment for square billets, and has promotion value.

[0082] Based on the same inventive concept, the present application embodiment also provides a billet processing device, please refer to Figure 2 , Figure 2 The structure diagram of the billet processing device in the embodiment of the present application includes: a crystallizer 201 and at least one straightening machine of the above embodiment. The crystallizer 201 is used to output the billet 203 to be formed. The billet 203 to be formed passes through the first straightening machine 202 and the second straightening machine 204 in sequence, and outputs the continuous casting billet 205.

[0083] The following is an introduction to the billet processing device provided in the embodiment of the present application. The billet processing device provided in the present embodiment is used to roll-form a continuous casting billet 203 with a cross-sectional size of 160mm×160mm, that is, the preset billet 203 width W is 160mm, and the preset billet 203 height T is 160mm.

[0084] The down-pressing roller of the tensioning and straightening machine is made of alloy steel 42CrMo, and the total axial length of the down-pressing roller is 250 mm. It includes a first roller segment 101, a second roller segment 102, and a third roller segment 103 which are sequentially arranged along the axial direction of the down-pressing roller. The second roller segment 102 includes a first sub-roller segment 1021, a second sub-roller segment 1022, and a third sub-roller segment 1023 which are sequentially arranged along the axial direction of the down-pressing roller; the first roller segment 101 includes a fourth sub-roller segment 1011 and a fifth sub-roller segment 1012 which are sequentially arranged along the axial direction of the down-pressing roller, and the third roller segment 103 includes a sixth sub-roller segment 1031 and a seventh sub-roller segment 1032 which are sequentially arranged along the axial direction of the down-pressing roller.

[0085] Among them, the roller profile curve of the second sub-roll segment 1022 is an arc curve that protrudes radially outward and has a curvature of 128.0, the axial width of the second sub-roll segment 1022 is 71.0 mm, the roller profile curve of the second sub-roll segment 1022 has a symmetry axis 104, and the symmetry axis 104 intersects the axis 105 of the pressing roller at right angles. The roller profile curve of the second sub-roll segment 1022 has a first high point 106, and the first high point 106 is located on the symmetry axis 104. The radial height of the first high point 106 is D1=350.0 mm.

[0086] The roller profile curves of the first sub-roller segment 1021 and the third sub-roller segment 1023 are arc-shaped curves that are opened radially outward, have a curvature of 128.0, an axial width of 34.0 mm, and are symmetrical about the symmetry axis 104 .

[0087] The roll profile curve of the fourth sub-roller segment 1011 intersects with the roll profile curve of the first sub-roller segment 1021 at the first low point 107, and the roll profile curve of the sixth sub-roller segment 1031 intersects with the roll profile curve of the third sub-roller segment 1023 at the second low point 109. The roll profile curves of the fourth sub-roller segment 1011 and the sixth sub-roller segment 1031 are arc-shaped curves with openings radially outward, a curvature of 16.0, and symmetric about the symmetry axis 104. The radial height D2 of the first low point 107 and the radial height D3 of the second low point 109 are 330.0 mm, and the axial distance L1 between the first low point 107 and the second low point 109 is 139 mm.

[0088] The roller profile curve of the fifth sub-roller segment 1012 intersects with the roller profile curve of the fourth sub-roller segment 1011 at the first transition point 108. The roller profile curve of the seventh sub-roller segment 1032 intersects with the roller profile curve of the sixth sub-roller segment 1031 at the second transition point 110. The axial distance L2 between the second transition point 110 and the first transition point 108 is 162.0 mm. The roller profile curves of the fifth sub-roller segment 1012 and the seventh sub-roller segment 1032 are arc-shaped curves symmetrical about the symmetry axis 104. The end point of the roller profile curve of the fifth sub-roller segment 1012 away from the first transition point 108 is the second highest point 111, and the end point of the roller profile curve of the seventh sub-roller segment 1032 away from the second transition point 110 is the third highest point 112. The radial heights of the second highest point 111 and the third highest point 112 are 390.0 mm.

[0089] The billet processing device provided in the embodiment of the present application is provided with two straightening machines. The two pressing rollers of the first straightening machine 202, the inner arc side pressing roller 2021 adopts the pressing roller provided in the above embodiment, and the outer arc side pressing roller 2022 adopts the traditional flat roller design. The schematic diagrams of the initial contact state and the contact state after pressing of the inner arc side pressing roller 2021 of the first straightening machine 202 and the billet 203 are shown as follows: Figure 3 , Figure 4As shown; the two pressing rollers of the second straightening machine 204, the inner arc side pressing roller 2041 and the outer arc side pressing roller 2042 are both the pressing rollers provided in the above embodiment, and the schematic diagrams of the initial contact state and the contact state after pressing of the pressing roller of the second straightening machine 204 and the billet 203 are respectively as shown in Figure 5 , Figure 6 shown.

[0090] The square billet processing device provided in the embodiment of the present application is used to perform continuous casting mechanical pressing on the width center position of the unpressed cast billet. The pressed cast billet obtained is the square billet. The total pressing amount of the inner and outer arc surfaces of the pressed billet can reach 14.5 mm. By way of example, the square billet processing device provided in the embodiment of the present application is used to perform continuous casting roller forming on the unpressed cast billet of steel grade SWRH82B. The specific process is shown in Table 1 below.

[0091] project value Cross section, mm×mm 160×160 Pulling speed, m / min 2.3 Superheat, ℃ 25 Specific water content, L / kg 1.0 The first tensioning and straightening machine position oil cylinder pressure, MPa 15.0 The oil cylinder pressure at the second straightening machine position, MPa 18.0 Depression, mm 14.5

[0092] like Figures 7 to 10 As shown, Figure 7 This is a schematic diagram of the low-magnification morphology of the unpressed ingot. Figure 8 This is a schematic diagram of the low-power lateral morphology of the pressed billet. Fig. 9 This is a schematic diagram of the low-magnification morphology of the unpressed ingot. Fig.10 This is a schematic diagram of the low-magnification longitudinal morphology of the pressed ingot.

[0093] from Figure 7 , 8 It can be seen that the shape of the unpressed ingot coming out of the crystallizer 201 and not passing through the straightening machine is irregular, while the shape of the pressed ingot after being rolled by the straightening machine is regular and has no deviation.

[0094] from Fig. 9 , 10 It can be seen that the core of the unpressed ingot that came out of the crystallizer 201 and did not pass through the straightening machine has obvious V-shaped segregation, central porosity, and central shrinkage defects. The core of the pressed ingot that was rolled by the straightening machine can be seen that the V-shaped segregation, central porosity, and central shrinkage defects are basically eliminated, with only slight central porosity and central segregation defects.

[0095] Compare the horizontal low-power center carbon segregation index of the unpressed ingot and the pressed ingot, such as Fig.11 As shown in the figure, the horizontal low-center carbon segregation index of the unpressed ingot fluctuates in a wide range, between 0.99 and 1.33, and the average horizontal low-center carbon segregation index is 1.13. The horizontal low-center carbon segregation index of the pressed ingot fluctuates in a smaller range, between 0.97 and 1.09, and the average horizontal low-center carbon segregation index is a smaller 1.01.

[0096] Understandably, Fig.11Each sample number on the horizontal axis corresponds to a group of sampling points for testing the carbon segregation index of the unpressed cast billet and the pressed cast billet.

[0097] The longitudinal low-power center carbon segregation index of the unpressed ingot and the pressed ingot is compared. Fig.12 As shown in the figure, the longitudinal low-center carbon segregation index of the unpressed billet fluctuates widely, between 1.05 and 1.27, and the average longitudinal low-center carbon segregation index is 1.14. The longitudinal low-center carbon segregation index of the 1.01-pressed billet fluctuates more narrowly, between 1.00 and 1.08, and the average longitudinal low-center carbon segregation index is 1.03.

[0098] Understandably, Fig.12 The distance of the middle horizontal axis along the longitudinal center line of the ingot is 1 cm, which means that the distance between two adjacent sampling points on the longitudinal center line of the ingot is 1 cm.

[0099] Through the above comparative analysis, it can be known that the square billet processing device provided in the embodiment of the present application adopts the first roll segment 101 and the third roll segment 103 with radial dimensions higher than the roll shape of the second roll segment 102. During the process of the two pressing rolls extruding the incompletely solidified molten steel from the upper and lower directions, the first roll segment 101 and the third roll segment 103 restrict the incompletely solidified molten steel to prevent the incompletely solidified molten steel from moving axially along the gap between the two pressing rolls, thereby preventing the square billet 203 from running off. Even if the pressing rolls are in series, under the restriction of the first roll segment 101 and the third roll segment 103, a higher pressing amount is guaranteed, and the square billet 203 can still be ensured not to run off when the pressing rolls are pressed down.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0101] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

Claims

1. A pressing roller, characterized in that: Mechanical reduction process for continuous casting billets; the reduction roll includes: A first roll section, a second roll section, and a third roll section arranged in sequence along the axial direction of the reduction roll; The radial dimension of the first roll section is greater than that of the second roll section, and is used to define one end of the billet during roll forming; The radial dimension of the third roll section is greater than that of the second roll section, and is used to define the other end of the billet during roll forming.

2. The pressing roller according to claim 1, characterized in that: The second roll section includes: A first sub-roll section, a second sub-roll section, and a third sub-roll section arranged in sequence along the axial direction of the reduction roll; The roll profile curve of the second sub-roll section is a curve that bulges radially outward, and the roll profile curve of the second sub-roll section has a symmetry axis, and the symmetry axis intersects the axis of the reduction roll perpendicularly; The radial dimension of the first sub-roll section is less than that of the second sub-roll section; The radial dimension of the third sub-roll section is less than that of the second sub-roll section.

3. The pressing roller according to claim 2, characterized in that: The roll profile curve of the first sub-roll section is a horizontal line or an arc curve with an opening radially outward; The roll profile curve of the third sub-roll section is a horizontal line or an arc curve with an opening radially outward; The roll profile curve of the third sub-roll section is symmetric with the roll profile curve of the second sub-roll section about the symmetry axis, and the roll profile curve of the second sub-roll section has a first high point, and the first high point is located on the symmetry axis.

4. The pressing roller according to claim 3, characterized in that: The first roll section includes: A fourth sub-roll section and a fifth sub-roll section arranged in sequence along the axial direction of the reduction roll; The roll profile curve of the fourth sub-roll section intersects the roll profile curve of the first sub-roll section at a first low point, and the radial height of the first low point satisfies the condition: D1 - 0.2T ≤ D2 < D1, where D1 is the radial height of the first high point, T is the preset height of the billet, and D2 is the radial height of the first low point; The roll profile curve of the fifth sub-roll section intersects the roll profile curve of the fourth sub-roll section at a first transition point, and the radial height of the first transition point is greater than the radial height of the first low point.

5. The pressing roller according to claim 4, characterized in that: The third roll section includes: A sixth sub-roll section and a seventh sub-roll section arranged in sequence along the axial direction of the reduction roll; The roll profile curve of the sixth sub-roll section intersects the roll profile curve of the third sub-roll section at a second low point, and the radial height of the second low point is less than the radial height of the first high point, and the radial height of the second low point satisfies the condition: D1 - 0.2T < D3 < D1; where D3 is the radial height of the second low point; The roll profile curve of the seventh sub-roll section intersects the roll profile curve of the sixth sub-roll section at a second transition point, and the radial height of the second transition point is greater than the radial height of the second low point.

6. The pressing roller according to claim 5, characterized in that The axial distance between the second low point and the first low point satisfies the condition 0.1W ≤ L1 ≤ 0.9W, where L1 is the axial distance between the second low point and the first low point, and W is the preset width of the billet; the axial distance between the second transition point and the first transition point satisfies the condition: 1.003W ≤ L2 ≤ 1.03W, and L2 > L1, where L2 is the axial distance between the second transition point and the first transition point.

7. The pressing roller according to claim 5, characterized in that: An endpoint of the roller profile curve of the fifth sub-roller segment away from the first transition point is a second high point, and a radial height of the second high point is greater than a radial height of the first transition point; An endpoint of the roller profile curve of the seventh sub-roller segment away from the second transition point is a third high point, and a radial height of the third high point is greater than a radial height of the second transition point; The axial distance between the third highest point and the second highest point satisfies the condition: L3≥L2, wherein L3 is the axial distance between the third highest point and the second highest point.

8. The pressing roller according to claim 7, characterized in that The roller profile curve of the fifth sub-roller segment is a straight line or a curve passing through the second high point and the first transition point; The roller profile curve of the seventh sub-roll segment is a straight line or a curve passing through the third high point and the second transition point.

9. A tensioning and leveling machine, characterized in that: The invention comprises a frame and at least one pressing roller according to any one of claims 1 to 7, wherein the pressing roller is rotatably connected to the frame.

10. A billet processing device, characterized in that: A crystallizer comprising at least one tension-leveling machine according to claim 9; The crystallizer is used to output the steel billet to be shaped; The straightening machine is used to mechanically press the steel billet to be shaped to obtain a square billet.

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