Straightening method for thin high-strength steel

Abstract

The straightening method comprises the steps that initial roll gap parameters of a straightening machine are set, the straightening machine conducts straightening treatment on a first steel plate in the first direction through the initial roll gap parameters, and the plate head portion of the first steel plate reaches a working roll at an outlet of the straightening machine; a first roll gap parameter of the straightening machine is set, the first steel plate is straightened in the second direction through the straightening machine by using the first roll gap parameter, the second direction is the direction opposite to the first direction, the plate head portion of the first steel plate reaches a working roll at an outlet of the straightening machine, and a first straightened steel plate is obtained; setting a second roll gap parameter of the straightener, and straightening the first straightened steel plate in the first direction by using the second roll gap parameter through the straightener, so that the plate head part and the plate tail part of the first straightened steel plate pass through a working roll at the outlet of the straightener to obtain a straightened steel plate. According to the straightening method, the thin-specification high-strength steel is fully straightened, and the problem that the straightening head of the thin-specification high-strength steel plate is excessively deformed is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of steel processing, and in particular relates to a straightening method for thin-gauge high-strength steel. Background Art

[0002] At present, the production mode of the straightening machine is that the steel plates enter the entrance of the straightening machine in sequence, and then reach the exit after being squeezed by the working rollers to complete the straightening process. However, for thin-gauge high-strength steel, when using a small roller diameter straightening machine for straightening, steel jamming is prone to occur. In order to avoid the occurrence of steel jamming, adjusting the parameters will result in unqualified straightening and the unevenness of the steel plate will not meet the requirements.

[0003] Taking the high-strength heat-treated plate (i.e. thin-gauge high-strength steel) with a thickness of 2-3 mm and a yield strength of 700 MPa to 1300 MPa as an example, Figure 1 and Figure 2 As shown in the figure, after quenching, the edge area or the middle area has a wavy deformation, so it needs to be straightened. However, when thin-gauge high-strength steel is normally straightened inside a small roller diameter straightening machine, the head deformation is too large, causing the end of the high-strength heat-treated steel plate to be torn in the straightening machine, or it is easy to get stuck and cannot be straightened. Summary of the invention

[0004] The embodiment of the present application provides a method for straightening thin-gauge high-strength steel, which can solve the problem of excessive deformation of the head of thin-gauge high-strength steel plates during straightening, and at the same time fully straighten the head of the thin-gauge high-strength steel plates to obtain qualified straightened products.

[0005] In a first aspect, the present application provides a method for straightening thin-gauge high-strength steel, comprising:

[0006] Setting initial roll gap parameters of the straightening machine, and straightening the first steel plate along a first direction using the initial roll gap parameters by the straightening machine, so that the head of the first steel plate reaches the working roll at the exit of the straightening machine;

[0007] Setting a first roll gap parameter of the straightening machine, and straightening the first steel plate along a second direction using the first roll gap parameter by the straightening machine, wherein the second direction is opposite to the first direction, so that the head of the first steel plate reaches the working roll at the entrance of the straightening machine, thereby obtaining a first straightened steel plate;

[0008] The second roll gap parameter of the straightening machine is set, and the first straightening steel plate is straightened along the first direction by the straightening machine using the second roll gap parameter, so that the head and tail of the first straightening steel plate pass through the working rollers at the outlet of the straightening machine to obtain the straightened steel plate.

[0009] According to an embodiment of the present application, the initial roll gap parameters include an entrance roll gap parameter and an exit roll gap parameter, and both the entrance roll gap parameter and the exit roll gap parameter are greater than or equal to the thickness of the first steel plate.

[0010] According to an embodiment of the present application, in the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the inlet of the straightener is greater than the speed of the first steel plate at the outlet of the straightener.

[0011] According to an embodiment of the present application, the speed of the first steel plate at the inlet of the straightener is 10 m / min to 15 m / min, and the speed of the first steel plate at the outlet of the straightener is 15 m / min to 20 m / min.

[0012] According to an embodiment of the present application, the first roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the entrance roll gap parameter is greater than the exit roll gap parameter.

[0013] According to an embodiment of the present application, in the first roll gap parameter, the inlet roll gap parameter is 0.5 mm to 5.0 mm, and the outlet roll gap parameter is -3.0 mm to 2.5 mm.

[0014] According to an embodiment of the present application, the second roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the thickness t of the first steel plate, the working roll diameter d, the absolute value of the entrance roll gap parameter |d1| and the exit roll gap parameter d2 satisfy the following relationship:

[0015] |d1|=(td / 100)*n-d2 (1),

[0016] And the inlet roll gap parameter d1 is less than the outlet roll gap parameter d2, wherein n is 0.8-2.8.

[0017] According to an embodiment of the present application, the second roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the entrance roll gap parameter is greater than the exit roll gap parameter.

[0018] According to an embodiment of the present application, in the second roll gap parameter, the inlet roll gap parameter is -3.0 mm to 2.5 mm, and the outlet roll gap parameter is 0.5 mm to 5.0 mm.

[0019] According to an embodiment of the present application, in the step of setting the second roll gap parameter of the straightening machine, the thickness t of the first steel plate and the inlet roll gap parameter and the outlet roll gap parameter satisfy the corresponding relationship of the following Table 1:

[0020] Table 1

[0021]

[0022]

[0023] In Table 1, negative values ​​in the entrance roll gap, such as -3.0 and -2.0, refer to the distance between the tangent lines of the working rolls at the entrance of the straightening machine when the working rolls in the upper roll box and the lower roll box at the entrance of the straightening machine are staggered with each other, that is, the entrance roll gap parameter d1 is a negative value.

[0024] The straightening method of thin-gauge high-strength steel in the embodiment of the present application first feeds the first steel plate to be straightened into the straightening machine along the first direction with the initial roll gap parameters, so that the head part of the first steel plate reaches the working roller at the outlet of the straightening machine, and the head part is preliminarily straightened; then the first steel plate is straightened by the straightening machine along the second direction opposite to the first direction with the first roll gap parameters, so that the head part of the first steel plate reaches the working roller at the entrance of the straightening machine, so that the deformed area of ​​the head part of the first steel plate can be gradually straightened by the working roller during the straightening process along the second direction, so as to prevent the head part of the first steel plate from being deformed too much and causing the straightening machine to jam the steel, or the head part from being broken during the straightening process; finally, by setting the second roll gap parameters of the straightening machine, the straightening machine is used to straighten the first straightening steel plate along the first direction, so that the head part and the tail part of the first straightening steel plate both pass through the working roller at the outlet of the straightening machine, and the deformed area of ​​the first straightening steel plate is further straightened, so as to obtain a straightened steel plate with good straightening effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 This is a schematic diagram of the wavy edge deformation of thin-gauge high-strength steel after quenching.

[0027] Figure 2 It is a schematic diagram of the wavy deformation in the middle of thin-gauge high-strength steel after quenching.

[0028] Figure 3 It is a schematic flow chart of a straightening method for thin-gauge high-strength steel provided in an embodiment of the present application.

[0029] Figure 4 It is a schematic diagram of the structure in the upper roller box of the straightening machine.

[0030] Figure 5 It is a schematic diagram of the structure of the working rolls in the upper roll box and the lower roll box.

[0031] Figure 6 This is a real picture of the steel plate after being straightened by the straightening method of thin-gauge high-strength steel of the present application in Example 1.

[0032] Figure 7This is a real picture of Example 1 after straightening using the existing straightening method.

[0033] Figure 8 Example 2 Actual picture of the steel plate after straightening by the straightening method of thin-gauge high-strength steel of the present application.

[0034] Fig. 9 This is a real picture of Example 2 after straightening using the existing straightening method.

[0035] Fig.10 Example 3 is a real picture of the steel plate after straightening by the straightening method of thin-gauge high-strength steel of the present application.

[0036] Fig.11 This is a picture of the actual object after straightening by using the existing straightening method in Example 3.

[0037] Explanation of the accompanying drawings: 1. Steel plate of thin-gauge high-strength steel; 100, wavelength of the wavy deformation area; 101, wavy deformation area at the edge; 102, wavy deformation area in the middle; 104, head of the plate; 105, tail of the plate; 2, upper roller box; 3, support roller; 4, intermediate roller; 5, working roller; 6, straightening machine entrance; 7, straightening machine exit; d1, entrance roller gap parameter; d2, exit roller gap parameter; D1, first direction, i.e., the direction in which the working roller rotates forward to advance the first steel plate; D2, second direction, i.e., the direction in which the working roller rotates backward to advance the first straightening steel plate; W, width direction of the first steel plate. DETAILED DESCRIPTION

[0038] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0039] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0040] In order to solve the problems in the prior art, the embodiment of the present application provides a straightening method for thin-gauge high-strength steel. The following first introduces the straightening method for thin-gauge high-strength steel provided in the embodiment of the present application.

[0041] Figure 3 A flow chart of a method for straightening thin-gauge high-strength steel provided in an embodiment of the present application is shown.

[0042] like Figure 3 As shown, the straightening method of thin gauge high strength steel includes:

[0043] S1, setting initial roll gap parameters of a straightening machine, and straightening the first steel plate along a first direction using the initial roll gap parameters by the straightening machine, so that the head of the first steel plate reaches the working roll at the exit of the straightening machine;

[0044] S2, setting a first roll gap parameter of a straightening machine, and straightening the first steel plate along a second direction using the first roll gap parameter by the straightening machine, wherein the second direction is a direction opposite to the first direction, so that the head of the first steel plate reaches the working roll at the entrance of the straightening machine, and a first straightened steel plate is obtained;

[0045] S3. Set the second roll gap parameter of the straightening machine, and use the second roll gap parameter to straighten the first straightening steel plate along the first direction through the straightening machine, so that the head and tail of the first straightening steel plate pass through the working rollers at the outlet of the straightening machine to obtain the straightened steel plate.

[0046] The straightening method of thin-gauge high-strength steel in the embodiment of the present application first feeds the first steel plate to be straightened into the straightening machine along the first direction with the initial roll gap parameter, so that the plate head portion of the first steel plate reaches the working roller at the outlet of the straightening machine, and the plate head portion is clamped and preliminarily straightened by the working roller of the straightening machine; then the first steel plate is straightened by the straightening machine along the second direction opposite to the first direction with the first roll gap parameter, so that the plate head portion of the first steel plate reaches the working roller at the entrance of the straightening machine, so that the deformation area of ​​the plate head portion of the first steel plate can be deformed along the second direction. During the straightening process, it is gradually straightened by the working roller to prevent the head part of the first steel plate from being deformed too much due to the large straightening force applied along the first direction, which may cause the straightener to get stuck, or the head part from breaking during the straightening process; finally, by setting the second roller gap parameters of the straightening machine, the straightening machine is used to straighten the first straightening steel plate along the first direction, so that the head part and the tail part of the first straightening steel plate both pass through the working roller at the outlet of the straightening machine, and the deformed area of ​​the first straightening steel plate is further straightened to obtain a straightening steel plate with good straightening effect.

[0047] The thin-gauge high-strength steel straightening method of the embodiment of the present application is suitable for straightening thin-gauge high-strength steel with a thickness of 2 mm to 6 mm.

[0048] In some embodiments of the present application, the initial roll gap parameters include an inlet roll gap parameter and an outlet roll gap parameter, and the inlet roll gap parameter and the outlet roll gap parameter are both greater than or equal to the thickness t of the first steel plate. Setting the inlet roll gap parameter and the outlet roll gap parameter of the initial roll gap parameters equal to the thickness t of the first steel plate can ensure that the first steel plate can pass normally, so that the first steel plate to be straightened can enter the roll gap of the working roller of the straightening machine, and the working roller transports the head portion of the first steel plate to be straightened to the position of the working roller at the outlet of the straightening machine, so as to roughly straighten and clamp the deformed area of ​​the head portion, and preliminarily straighten the head portion with a smaller straightening force, so as to reduce the degree of deformation of the first steel plate during the straightening process of the straightening machine along the second direction, thereby obtaining the first straightened steel plate.

[0049] In some embodiments of the present application, in the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the outlet of the straightener is greater than the speed of the first steel plate at the inlet of the straightener.

[0050] In the embodiment of the present application, in the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the straightener exit is greater than the speed of the first steel plate at the straightener entrance, so that the conveying speed of the head portion of the first steel plate from the straightener entrance to the straightener exit gradually increases, that is, the faster rotation speed of the working roller at the straightener exit is used to drive the head portion of the first steel plate to move forward, so as to prevent the head portion of the first steel plate from being deformed and stuck between the working rollers due to large force in the straightener. Combined with the fact that the inlet roll gap parameter and the outlet roll gap parameter in the above-mentioned initial roll gap parameters are both equal to the thickness of the first steel plate, it can further prevent the head portion of the first steel plate from being stuck in the working roller, causing the head portion of the first steel plate to tear and jam.

[0051] In some embodiments of the present application, in the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the entrance of the straightener is 10m / min to 15m / min, and the speed of the first steel plate at the exit of the straightener is 15m / min to 20m / min. Optionally, in the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the entrance of the straightener is 11m / min, 12m / min, 13m / min, 14m / min, and correspondingly, the speed of the first steel plate at the exit of the straightener is 16m / min, 17m / min, 18m / min, 19m / min, which is greater than the speed at the entrance of the straightener.

[0052] In some embodiments of the present application, in the step of setting the first roll gap parameter of the straightening machine, the first roll gap parameter also includes an entrance roll gap parameter and an exit roll gap parameter, and the entrance roll gap parameter is greater than the exit roll gap parameter.

[0053] In the embodiment of the present application, by setting the inlet roll gap parameter of the first roll gap parameter to be greater than the outlet roll gap parameter, the straightening machine can form a straightening area from small to large from the outlet of the straightening machine to the inlet of the straightening machine, so that the head portion of the first steel plate is gradually applied with a straightening force varying from large to small during the straightening process along the second direction, so as to perform the main straightening process. It can be understood that since the portion of the first steel plate other than the head portion does not enter the straightening machine, the head portion is gradually subjected to a straightening force varying from large to small in the straightening area from small to large along the second direction under the action of external traction, and the deformed area of ​​the head portion is gradually straightened, thereby avoiding the continuous application of a large force along the first direction to cause the head portion of the first steel plate to be straightened to undergo a large deformation and then get stuck in the roll gap of the working roll, resulting in problems such as steel jamming or tearing that cannot be straightened.

[0054] In some embodiments of the present application, the first roll gap parameter includes an inlet roll gap parameter and an outlet roll gap parameter, the inlet roll gap parameter is 0.5 mm to 5.0 mm, and the outlet roll gap parameter is -3.0 mm to 2.5 mm. By setting the first roll gap parameter, the working rollers for straightening treatment apply a straightening force gradually from large to small to the head portion of the first steel plate, so that when the head portion of the first steel plate is straightened along the second direction, the working rollers of the straightening machine gradually move relatively from the tail portion of the first steel plate to the head portion, so that the deformation area of ​​the head portion is first subjected to a larger straightening force of the working rollers, thereby generating a deformation with a larger amplitude variation; then, adapted to the straightening area set from small to large, a smaller straightening force is gradually applied to the deformation area of ​​the head portion, and the deformation area of ​​the head portion is gradually straightened to generate a deformation with a smaller amplitude variation; since the part of the first steel plate other than the head portion does not enter the straightening machine, that is, the tail portion will not be stuck in the working rollers of the straightening machine, the deformation area of ​​the head portion can be gradually straightened, so that the deformation area of ​​the head portion reaches the working rollers at the entrance of the straightening machine, and the first straightened steel plate is obtained; then, the first straightened steel plate is prevented from being excessively deformed at the head portion during the subsequent straightening process, resulting in steel jamming in the straightening machine, or even being torn.

[0055] In some embodiments of the present application, the second roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the thickness t of the first steel plate, the working roll diameter d, the absolute value of the entrance roll gap parameter |d1| and the exit roll gap parameter d2 satisfy the following relationship:

[0056] |d1|=(td / 100)*n-d2 (1),

[0057] And the inlet roll gap parameter d1 is less than the outlet roll gap parameter d2, wherein n is 0.8-2.8.

[0058] In the embodiments of the present application, the thickness t of the first steel plate, the working roll diameter d, the absolute value of the entrance roll gap parameter |d1| and the exit roll gap parameter d2 satisfy formula (1) and the limiting conditions, so that the straightening machine can use the straightening method of the present application to effectively straighten the head part of the first steel plate and even the first steel plate as a whole, thereby avoiding the head part of the thin-gauge high-strength steel from being torn in the straightening machine, or the occurrence of steel jamming, inability to straighten, etc.

[0059] In an embodiment of the present application, after the first steel plate is straightened along the second direction with the first roll gap parameters, the deformation degree of the head portion of the first straightened steel plate is reduced compared with the deformation degree of the head portion of the first steel plate. At this time, the head portion of the first straightened steel plate can be straightened along the first direction with the second roll gap parameters with a smaller entrance roll gap adoption number, that is, a larger straightening force continues to be applied, thereby completing the straightening of thin-gauge high-strength steel and obtaining a straightened steel plate.

[0060] In some embodiments of the present application, in the step of setting the second roll gap parameter of the straightening machine, the thickness of the first steel plate and the inlet roll gap parameter and the outlet roll gap parameter satisfy the corresponding relationship of the following Table 1:

[0061] Table 1

[0062] Thickness of the first steel plate / mm Entrance roll gap parameter d1 / mm Exit roller gap parameter d2 / mm 2 -3.0～-2.0 0.5～1.2 3 -2.0～-0.5 1.2～2.2 4 -0.5～0.5 2.2～3.2 5 0.5～1.5 3.2～4.2 6 1.5～2.5 4.2～5.0

[0063] In Table 1, the negative values ​​in the entrance roll gap, such as -3.0 and -2.0, refer to the distance between the tangent lines of the working rolls at the entrance of the straightening machine when the working rolls of the upper roll box and the lower roll box at the entrance of the straightening machine are staggered with each other, that is, the entrance roll gap parameter d1 is a negative value, such as Figure 5 shown.

[0064] In some embodiments of the present application, the second roll gap parameter includes an inlet roll gap parameter and an outlet roll gap parameter, the inlet roll gap parameter is 0.5 mm to 5.0 mm, and the outlet roll gap parameter is -3.0 mm to 2.5 mm. By setting the second roll gap parameter, the straightening machine can straighten the head of the second straightening steel plate again on the basis of the second straightening steel plate, and finally complete the straightening process of the first steel plate to obtain a straightening steel plate that meets the requirements.

[0065] According to the embodiments of the present application, Figure 5 As shown, the entrance roll gap parameter refers to the distance between the working roll tangents of the upper roll box and the lower roll box at the entrance 6 of the straightening machine, that is, the entrance roll gap parameter d1; the exit roll gap parameter refers to the distance between the working roll tangents of the upper roll box and the lower roll box at the exit 7 of the straightening machine, that is, the exit roll gap parameter d2.

[0066] The straightening method for thin-gauge high-strength steel in the embodiment of the present application is suitable for a small-roller-diameter straightening machine with a working roll diameter of ≤80 mm, a large number of working rolls, and a high risk of steel jamming.

[0067] The straightening method for thin-gauge high-strength steel in the embodiment of the present application is suitable for straightening thin-gauge high-strength steel with a thickness of 0.5 mm to 6 mm and a yield strength of 700 MPa to 1300 MPa.

[0068] The advantages of the technical solution of the present application are further illustrated by specific examples and comparative examples. Straightening equipment used: Electric single-roller driven 21-roller straightening machine, a 3-roller system, such as Figure 4As shown, it includes an upper roll box 2 and a lower roll box arranged below the upper roll box 2; the upper roll box and the lower roll box are respectively provided with upper rolls and lower rolls. The upper roll and the lower roll are composed of working rolls 5, intermediate rolls 4, and support rolls 3. The upper roll and the lower roll are respectively provided in the upper roll box 2 and the lower roll box. The lower roll box is provided with working rolls 5, intermediate rolls 4, and support rolls 3 from top to bottom, which are arranged opposite to the upper roll in the upper roll box 2. The diameter of the working roll is 72 mm, and there are 21 working rolls in total, of which 10 are working rolls arranged in the upper roll box, and 11 are working rolls arranged in the lower roll box; the working rolls are all fixed, and the roll gap control system controls their lifting and lowering to complete the straightening of strip steels of different thicknesses within the working thickness range. The bending roll is located below the lower roll box, and there are 7 of them in total. The bending roll value is the difference between the bending roll height and the 0 position.

[0069] As described in the background technology section, if the straightening machine with a small roller diameter is set according to the normal roller gap straightening parameters, such as the entrance roller gap parameter is set to -1.0mm and the exit roller gap parameter is 1.6mm, the thin high-strength steel plate receives a large straightening force at the entrance, and the plate head is deformed greatly, and it is easy to get stuck in the roller gap between the working rollers during the straightening process, resulting in steel jamming or even steel plate tearing. The present application makes improvements on this, and provides the following embodiments and comparative examples to further illustrate the technical solution of the present application, so as to make the technical solution clearer and more specific.

[0070] Example 1

[0071] The steel grade LG960QT is selected, and the steel plate with the specifications of 3mm thickness, 1400mm width and 7900mm length is used as the incoming material for straightening after quenching. There is a wavy deformation area with a wavelength of 20mm in the middle of the steel plate, and the head of the steel plate is buckled down by 15mm.

[0072] The steel plate is straightened according to the thin gauge high strength steel straightening method of the present application, comprising:

[0073] S1. Set the initial roll gap parameters of the straightening machine: the inlet roll gap parameters and the outlet roll gap parameters are both equal to the thickness of the first steel plate, which is 3 mm; the straightening machine is rotated in the forward direction and the initial roll gap parameters are used to straighten the first steel plate (i.e., the thin-gauge high-strength steel plate 1) along the first direction D1, so that the plate head portion 104 of the first steel plate reaches the 21st working roller at the outlet of the straightening machine, and the working roller clamps and straightens the deformed area of ​​the plate head portion of the first steel plate;

[0074] S2, setting the first roll gap parameter of the straightening machine, the entrance roll gap parameter is 1.6 mm, and the exit roll gap parameter is -1.0 mm; the first steel plate is straightened along the second direction D2 by the reverse rotation of the straightening machine and using the first roll gap parameter, the second direction D2 is opposite to the first direction D1, so that the plate head portion 104 of the first steel plate reaches the first working roller 5 at the entrance of the straightening machine, and the first straightened steel plate is obtained;

[0075] S3, set the second roll gap parameter of the straightening machine, the inlet roll gap parameter is -1.0mm, and the outlet roll gap parameter is 1.6mm; the first straightening steel plate is straightened along the first direction D1 by the straightening machine using the second roll gap parameter, so that the head portion 104 and the tail portion 105 of the first straightening steel plate both pass through the 21st working roller at the outlet of the straightening machine, and the straightened steel plate is obtained. Figure 6 As shown, the steel plate passes through the straightening machine smoothly, the unevenness of the steel plate head is about 2mm / m, and the straightening result is qualified.

[0076] Comparative Example 1

[0077] The steel type and specification are the same as those in Example 1. The steel plate is straightened using an electric single-roller driven 21-roller straightening machine with the straightening parameters of the normal straightening mode: the entrance roll gap is -1.0mm, and the exit roll gap is 1.6mm. Steps S2 and S3 of Example 1 are not performed. Figure 7 As shown, the steel plate is deformed too much inside the roller box of the straightening machine, and the head of the steel plate is stuck and partially cracked.

[0078] Example 2

[0079] Taking the steel grade LG700T, a steel plate with a thickness of 4mm, a width of 1500mm and a length of 10400mm as an example, the steel is used as the incoming material for straightening after tempering, and there is a wavy deformation area with a wavelength of 15mm at the edge of the steel plate.

[0080] The steel plate is straightened according to the straightening method of thin-gauge high-strength steel in the embodiment of the present application, comprising:

[0081] S1. Set the initial roll gap parameters of the straightening machine: the entrance roll gap parameter and the exit roll gap parameter are both 4 mm; use the first roll gap parameter to straighten the first steel plate (i.e., the thin-gauge high-strength steel plate 1) along the first direction D1 by the straightening machine, so that the plate head portion 104 of the first steel plate reaches the first working roller at the exit of the straightening machine, and the working roller clamps and straightens the deformed area of ​​the plate head portion of the first steel plate;

[0082] S2, setting the first roll gap parameter of the straightening machine, the entrance roll gap parameter is 2.2mm, and the exit roll gap parameter is -0.5mm; the first straightening steel plate is straightened along the second direction D2 by the straightening machine using the second roll gap parameter, the second direction D2 is opposite to the first direction D1, so that the plate head part 104 of the first straightening steel plate reaches the first working roller 5 at the entrance of the straightening machine, and the first straightening steel plate is obtained;

[0083] S3, set the third roll gap parameter of the straightening machine, the inlet roll gap parameter is -0.5mm, and the outlet roll gap parameter is 2.2mm; the first straightening steel plate is straightened along the first direction D1 by the straightening machine using the third roll gap parameter, so that the head portion 104 and the tail portion 105 of the first straightening steel plate both pass through the 21st working roller at the outlet of the straightening machine, and the straightened steel plate is obtained. Figure 8 As shown, the steel plate passes through the straightening machine smoothly, the unevenness of the steel plate is 3mm / m, and the surface of the plate head is uniform and flat, which meets the straightening requirements.

[0084] Comparative Example 2

[0085] The steel type and specification are the same as those in Example 2. The steel plate is straightened using an electric single-roller driven 21-roller straightening machine with the straightening parameters of the normal straightening mode: the entrance roll gap is -0.5mm, and the exit roll gap is 2.2mm. Steps S2 and S3 of Example 2 are not performed. When the steel plate is straightened inside the roller box of the straightening machine, Fig. 9 As shown, the steel plate head is severely deformed, there is a great risk of steel jamming, and it cannot pass through the straightening machine.

[0086] Example 3

[0087] Taking the steel grade NM450, the steel plate with the specifications of 3mm thickness, 1400mm width and 7400mm length as an example, as the incoming material for straightening after quenching, there is a wavy deformation area with a wavelength of 15mm in the middle of the steel plate, and the head of the steel plate is buckled down by 15mm.

[0088] The steel plate is straightened according to the straightening method of thin-gauge high-strength steel in the embodiment of the present application, comprising:

[0089] S1. Set the initial roll gap parameters of the straightening machine: the entrance roll gap parameter and the exit roll gap parameter are both 3 mm; use the first roll gap parameter to straighten the first steel plate (i.e., the thin-gauge high-strength steel plate 1) along the first direction D1 by the straightening machine, so that the plate head portion 104 of the first steel plate reaches the 21st working roller at the exit of the straightening machine, and the working roller clamps and straightens the deformed area of ​​the plate head portion of the first steel plate;

[0090] S2, setting the first roll gap parameter of the straightening machine, the entrance roll gap parameter is 1.7 mm, and the exit roll gap parameter is -1.7 mm; the first steel plate is straightened along the second direction D2 by the straightening machine using the first roll gap parameter, the second direction D2 is opposite to the first direction D1, so that the plate head portion 104 of the first steel plate reaches the first working roller 5 at the entrance of the straightening machine, and the first straightened steel plate is obtained;

[0091] S3, set the second roll gap parameter of the straightening machine, the inlet roll gap parameter is -1.7mm, and the outlet roll gap parameter is 1.7mm; the first straightening steel plate is straightened along the first direction D1 by the straightening machine using the second roll gap parameter, so that the head portion 104 and the tail portion 105 of the first straightening steel plate both pass through the 21st working roller at the outlet of the straightening machine, and the straightened steel plate is obtained. Fig.10 As shown, there is no deformation on the head of the steel plate and it passes through the straightening machine smoothly. The unevenness of the steel plate is 3mm / m, which meets the straightening requirements.

[0092] Comparative Example 3

[0093] The steel type and specification are the same as those in Example 3. The steel plate is straightened using an electric single-roller driven 21-roller straightening machine with the straightening parameters of the normal straightening mode: the entrance roll gap is -1.7mm, and the exit roll gap is 1.7mm. The steel plate is straightened inside the straightening machine. Steps S2 and S3 of Example 3 are not performed. Fig.11 As shown, the steel plate straightened according to the normal straightening mode has its head bent and deformed, and the straightening result is unqualified.

[0094] It can be concluded from the straightening results of the above-mentioned embodiments and comparative examples that the straightening method for thin-gauge high-strength steel in the embodiments of the present application can effectively straighten thin-gauge high-strength steel, solve the problem of excessive deformation of the head of thin-gauge high-strength steel plates during straightening, and at the same time fully straighten the head of the thin-gauge high-strength steel plates to obtain qualified straightened products.

[0095] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A method for straightening thin-gauge high-strength steel, characterized in that: include: Setting initial roll gap parameters of a straightening machine, and using the initial roll gap parameters to straighten the first steel plate along a first direction by the straightening machine, so that the head of the first steel plate reaches the working roll at the exit of the straightening machine; Setting a first roll gap parameter of a straightening machine, and straightening the first steel plate along a second direction using the first roll gap parameter by the straightening machine, wherein the second direction is opposite to the first direction, so that the head of the first steel plate reaches the working roll at the entrance of the straightening machine, thereby obtaining a first straightened steel plate; The second roll gap parameter of the straightening machine is set, and the first straightening steel plate is straightened along a first direction by the straightening machine using the second roll gap parameter, so that the head and tail parts of the first straightening steel plate pass through the working rollers at the outlet of the straightening machine to obtain the straightened steel plate.

2. The method for straightening thin-gauge high-strength steel according to claim 1, characterized in that: The initial roll gap parameters include an entrance roll gap parameter and an exit roll gap parameter, and both the entrance roll gap parameter and the exit roll gap parameter are greater than or equal to the thickness of the first steel plate.

3. The method for straightening thin-gauge high-strength steel according to claim 1, characterized in that: In the step of setting the initial roll gap parameters of the straightener, the speed of the first steel plate at the outlet of the straightener is greater than the speed of the first steel plate at the inlet of the straightener.

4. The method for straightening thin-gauge high-strength steel according to claim 3, characterized in that: The speed of the first steel plate at the inlet of the straightening machine is 10m / min to 15m / min, and the speed of the first steel plate at the outlet of the straightening machine is 15m / min to 20m / min.

5. The method for straightening thin-gauge high-strength steel according to claim 1, characterized in that: The first roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the entrance roll gap parameter is greater than the exit roll gap parameter.

6. The method for straightening thin-gauge high-strength steel according to claim 5, characterized in that: Among the first roll gap parameters, the inlet roll gap parameter is 0.5 mm to 5.0 mm, and the outlet roll gap parameter is -3.0 mm to 2.5 mm.

7. The method for straightening thin-gauge high-strength steel according to any one of claims 1 to 6, characterized in that: The second roll gap parameter includes an inlet roll gap parameter and an outlet roll gap parameter, and the thickness t of the first steel plate, the roll diameter d of the working roll, the absolute value of the inlet roll gap parameter |d1| and the outlet roll gap parameter d2 satisfy the following relationship: |d1|=(td / 100)*n-d2 (1), And the inlet roll gap parameter d1 is less than the outlet roll gap parameter d2, wherein n is 0.8-2.

8.

8. The method for straightening thin-gauge high-strength steel according to claim 7, characterized in that: The second roll gap parameter includes an entrance roll gap parameter and an exit roll gap parameter, and the entrance roll gap parameter is smaller than the exit roll gap parameter.

9. The method for straightening thin-gauge high-strength steel according to claim 7, characterized in that: Among the second roll gap parameters, the inlet roll gap parameter is -3.0 mm to 2.5 mm, and the outlet roll gap parameter is 0.5 mm to 5.0 mm.

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