A method for controlling the crown of hot-rolled wide strip steel

Abstract

The present invention provides a control method for the convexity of hot-rolled wide strip steel, belonging to the technical field of strip steel production. The hot-rolled wide strip steel is rolled by multiple groups of rollers, and the following conditions are met: 1) the lateral contact width between the rollers and the hot-rolled wide strip steel is less than the width of the hot-rolled wide strip steel; 2) the rollers of the roller group are convex rollers, and starting from the first roller group, the curvature radius of the convexity of the rollers of the subsequent roller groups gradually increases, and the roller convexity, the convexity curvature radius and the required number of roller groups of each roller group need to be determined according to the original convexity, thickness and width of the hot-rolled wide strip steel; 3) the rollers of the roller group adopt a combined structure. The hot-rolled wide strip steel rolled by the present invention is sheared into medium-wide strip steel coils in a longitudinal shearing unit. When the medium-wide strip steel is rolled in a cold rolling unit, it has high efficiency, good plate shape, small lateral thickness difference and high yield rate; especially when it is sheared into two rolls of steel coils with the same width in the longitudinal shearing unit, the quality of the finished product is improved to the greatest extent and the economic benefit is most obvious.

Description

Technical Field

[0001] The invention belongs to the technical field of strip steel production, and in particular relates to a method for controlling the convexity of hot-rolled wide strip steel. Background Art

[0002] Hot-rolled wide steel coil is the raw material of cold-rolled wide steel coil. It can be directly pickled and then cold-rolled to produce cold-rolled wide steel of various thicknesses. In the production process of hot-rolled wide steel, in order to ensure the stability of the hot rolling unit, the hot-rolled wide steel is required to have a certain convexity. Hot-rolled wide steel coil is also a widely used raw material in the production of cold-rolled medium-wide steel. First, the hot-rolled wide steel coil must be cut into medium-wide steel coils of the required width in the longitudinal shear unit, then pickled, and then rolled in the medium-wide cold rolling unit to produce cold-rolled medium-wide steel of various thicknesses.

[0003] The hot-rolled wide strip steel coil is sheared into two medium-wide strip steel coils of equal width in the longitudinal shearing unit. Since the wide strip steel has a certain convexity in cross section, the thickness of the two sides of the wide strip steel is less than the thickness in the middle of the wide strip steel. The difference in thickness between the two sides of the two medium-wide strip steel coils of equal width sheared from the hot-rolled wide strip steel is the largest. When the medium-wide strip steel coil is cold-rolled after pickling, according to product requirements, the thickness of the two sides of the cold-rolled medium-wide strip steel should be equal. However, the thickness of the two sides of the medium-wide strip steel as the raw material is different. The edge with a larger raw material thickness has a larger reduction and more elongation after cold rolling; the edge with a smaller raw material thickness has a smaller reduction and less elongation. After rolling, the plate shape of the medium-wide strip steel becomes a single-sided wave, and severe single-sided waves will cause the strip steel to break during rolling.

[0004] At present, in order to reduce the single-side wave and strip breakage failures in the rolling production of hot-rolled wide strip steel coils cut into two medium-wide strip steel coils of equal width by the longitudinal shearing unit, the following measures are taken: 1) Within the range of the quality allowance of medium-wide strip steel cold-rolled products, the edge thickness of the medium-wide strip steel cut in the middle of the hot-rolled wide strip steel corresponds to the edge thickness of the medium-wide strip steel with thick raw material thickness, and the edge thickness of the finished product is also thick, and the edge thickness of the finished product is also thin; the purpose is to control the difference in elongation of the two edges of the medium-wide strip steel during the rolling process within a certain range, and further to say, to control the single-side wave of the rolled piece within the range allowed for normal rolling; 2) reduce the rolling speed; that is, timely manual intervention in production, the disadvantage is that the output is reduced and the yield rate is low; 3) according to the requirements of the plate shape and transverse thickness difference of cold-rolled medium-wide strip steel products, if the convexity of the hot-rolled wide strip steel exceeds a certain value, the medium-wide strip steel coil produced by the intermediate shearing of the hot-rolled wide strip steel will not be able to be cold-rolled into a qualified medium-wide strip steel product; the hot-rolled wide strip steel coil will be downgraded, resulting in economic losses.

[0005] The purpose of this technical invention is to eliminate the defects of the medium and wide strip steel coils produced by intermediate shearing and used as cold rolling raw materials, and the medium and wide strip steel products have poor plate shape and excessive thickness on both sides after cold rolling.

[0006] The technical solution adopted by this technical invention is to locally press down the area with the largest convexity of the cross section of the hot-rolled wide strip steel before longitudinal shearing and dividing the hot-rolled wide strip steel coil, and the roller used for pressing down adopts a large-diameter crown roller, and rolls two or more times; the crown curvature radius of the roller adopts a pre-designed crown curvature radius; after eliminating or reducing the crown of the hot-rolled wide strip steel, it is sheared into two medium-width strip steel coils of equal width in the longitudinal shearing unit. The medium-width wide strip steel coil produced after the technical treatment of the present invention fully meets the technical requirements of the raw materials for the cold rolling of medium-width wide strip steel.

[0007] The economic benefits of the technology of the present invention are as follows: improving the efficiency of cold rolling of medium-width steel coils; improving the plate shape of medium-width steel products and reducing the lateral tolerance, avoiding the production of unqualified medium-width steel products by cold rolling of medium-width steel coils produced by intermediate shearing of hot-rolled wide steel, improving the yield rate, and reducing or even avoiding economic losses. Summary of the invention

[0008] The present invention provides a method for controlling the convexity of hot-rolled wide strip steel, aiming to eliminate or reduce the convexity of the cross section of the hot-rolled wide strip steel. After the hot-rolled wide strip steel of the present invention is sheared into two medium-wide strip steel coils of equal width by a longitudinal shearing unit, the finished product after subsequent rolling by a medium-wide strip cold rolling mill will no longer have defects such as poor plate shape and excessive transverse thickness difference in the finished product due to the convexity of the raw material exceeding the standard requirements.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A method for controlling the convexity of hot-rolled wide strip steel is provided, comprising the following steps:

[0011] The hot-rolled wide strip is rolled by multiple groups of rollers, the contact width between the rollers and the cross-section of the strip is smaller than the width of the strip, and the contact area between the rollers and the cross-section of the strip is located in the middle of the cross-section of the strip; the amount of roller reduction on the hot-rolled wide strip is smaller than the convexity of the cross-section of the hot-rolled wide strip; the convexity curvature radii of the rollers of the multiple groups of rollers are different, wherein the rollers in each group of rollers have a preset convexity curvature radius, and along the rolling direction of the strip, the convexity curvature radii of the rollers of subsequent roller groups gradually increase.

[0012] In a possible implementation, multiple groups of rollers roll hot-rolled wide strips, and the contact width between the rollers and the cross section of the strip is smaller than the width of the strip, and the contact width ranges from 10% to 30% of the width of the hot-rolled wide strip; and the contact area between the rollers and the cross section of the strip is located in the middle of the cross section of the strip;

[0013] In one possible implementation, multiple groups of rollers roll hot-rolled wide strips, and the reduction in thickness of the hot-rolled strip at the contact portion between the rollers and the strip is no more than the original convexity of the hot-rolled strip, and is 30% to 100% of the original convexity of the hot-rolled strip.

[0014] In a possible implementation, multiple groups of rollers roll hot-rolled wide strips, each group of rollers uses crowned rollers, and the curvature radius of the crown of each group of rollers is related to the original crown, width and thickness of the hot-rolled strip;

[0015] In a possible implementation, multiple groups of rollers roll hot-rolled wide strips, and the first group of rollers rolls the hot-rolled wide strip with crowned rollers to achieve the first rolling deformation; the radius of curvature of the roller crown of the second group of rollers is greater than the radius of curvature of the roller crown of the first group of rollers, and the initial contact position of the strip after the rollers of the second group of rollers and the rollers of the first group of rollers are rolled is symmetrically moved from the middle position of the strip when the first group of rollers are rolled to two positions deviating from the middle of the strip, and the distance between the initial contact position and the middle of the strip depends on the ratio of the radius of curvature of the roller crown of the second group of rollers to the radius of curvature of the roller crown of the first group of rollers; rolling with crowned rollers helps the pressed metal material to move in the width direction of the strip; when the second group of rollers are rolled, the initial contact position of the rollers and the wide strip moves toward the two edges of the wide strip, further prompting the metal material pressed in the middle of the wide strip to move in the width direction of the strip.

[0016] In a possible implementation, each group of the roller sets includes an upper roller and a lower roller, and the upper roller and the lower roller have the same structure;

[0017] Wherein, the middle part of the upper roll shaft and the middle part of the lower roll shaft are both connected with the working roll ring, and the working roll ring and the roll shaft are connected by a key.

[0018] Among them, when the roll ring of the working roll is damaged or replaced with other models of products, the roll ring of the working roll can slide out from the roll shaft.

[0019] Among them, the upper roller and the lower roller can be driven by a single roller or a double roller;

[0020] In a possible implementation, each group of the roll groups includes an upper roll and a lower roll, and the roll diameters of the upper roll and the lower roll are; the convexity control effect of rolling hot-rolled wide strip steel using a large roll diameter is better than the convexity control effect of rolling wide strip steel using a small diameter roll under the same conditions.

[0021] The present invention provides a method for controlling the convexity of hot-rolled wide strip steel. Compared with the prior art, the hot-rolled wide strip steel coil is directly sheared into two medium-wide strip steel coils of equal width in a longitudinal shearing unit without being treated, and then pickled and rolled in a medium-wide strip steel cold rolling mill. The hot-rolled wide strip steel coil is first treated by the present invention, then sheared into two medium-wide strip steel coils of equal width in a longitudinal shearing unit, then pickled, and rolled in a medium-wide strip steel cold rolling mill. The production efficiency is significantly higher, the quality of the product plate shape is good, the lateral thickness difference is reduced, and the yield rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic cross-sectional view of an existing hot-rolled wide strip steel;

[0023] Figure 2 It is a schematic diagram of the cross section of the deformation zone of the upper roll and the lower roll of the roll group rolling the hot-rolled wide strip steel;

[0024] Figure 3 A partial view of a rolling section for rolling a hot-rolled wide strip of steel by an upper roll and a lower roll of a roll group;

[0025] Figure 4 is a schematic diagram of the rolling force P and the horizontal component force Pt;

[0026] Figure 5 A schematic cross-sectional view of the deformation zone of the upper roll, the lower roll and the wide strip of the first roll group and the second roll group during rolling;

[0027] Figure 6 Schematic diagram of the longitudinal section of the deformation zone during rolling with rollers of different diameters

[0028] Figure 7 It is a schematic diagram of the assembly of the roller in the embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the application of an embodiment of the present invention in a hot-rolled wide strip steel slitting machine group;

[0030] Fig. 9 for Figure 8 The enlarged schematic diagram of the middle A part;

[0031] Fig.10 for Figure 8 The enlarged schematic diagram of the middle B part;

[0032] Fig.11 for Figure 8 The enlarged schematic diagram of the middle C part;

[0033] Explanation of reference numerals: 1. upper roller; 11. crown roller contour line of the upper roller; 2. lower roller; 21. crown roller contour line; 3. rolled product (hot-rolled wide strip steel); 30. crown roller contour line of the upper roller and the cross-sectional contour line of the hot-rolled wide strip steel before rolling deformation; 4. hot-rolled wide strip steel longitudinal shearing unit; 41. uncoiler; 42. centering device; 43. clamping and straightening device; 44. first rolling mill; 45. second rolling mill; 46. first looper pit; 47. longitudinal shearing device; 48. second looper pit; 49. outlet clamping and tensioning device; 410. coiling machine; 5. roller; 5.1. roller shaft; 5.2 working roller ring; 50. pressing area of ​​the lower roller on the hot-rolled wide strip steel; 51. the portion of the hot-rolled wide strip steel cross section without the section line; 52. roller shaft; DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] A method for controlling the convexity of hot-rolled wide strip steel provided by the present invention is now described.

[0036] As attached Figure 1 As shown, the cross section of the hot-rolled wide strip is a nearly rectangular section with a certain convexity, which is thick in the middle and thin on both sides. Maintaining a certain convexity is a requirement for the stable production of the wide strip hot rolling group. The definition of the convexity of the hot-rolled wide strip is the difference between the middle thickness and the edge thickness of the hot-rolled wide strip.

[0037] As attached Figure 2 As shown, the cross-sectional schematic diagram of the upper roll 1 and the lower roll 2 of the roll group rolling the hot-rolled wide steel 3; Figure 2 It can be seen that the pressing area 50 of the upper roller 1 and the lower roller 2 on the hot-rolled wide steel strip 3 is in the middle area of ​​the hot-rolled wide steel strip, and the width of the pressing area is smaller than the width of the hot-rolled wide steel strip; the width of the middle pressing area is 10% to 30% of the width of the hot-rolled wide steel strip; Figure 2 The portion 51 without the section line in the cross section of the hot-rolled wide strip is not directly pressed down by the rolling rollers. During the process of the rolling group rolling the hot-rolled wide strip, the metal in the pressing zone 50 is restricted from moving along the rolling direction, which is beneficial to the movement of the metal in the pressing zone 50 along the width direction of the plate and strip.

[0038] By the attached Figure 3 It can be seen that the upper and lower roll surfaces are convex roll surfaces;

[0039] By the attached Figure 3 Further analysis shows that the crown roller contour line 11 of the upper roller and the cross-sectional contour line 30 of the hot-rolled wide strip before rolling deformation, and the crown roller contour line 21 of the lower roller and the cross-sectional contour line 30 of the hot-rolled strip before rolling deformation respectively form two approximate crescent-shaped areas; the metal in these two crescent-shaped areas is squeezed by the rollers and moves in the rolling direction and the strip width direction, moving along the rolling direction to form extension, and moving along the width direction to form widening.

[0040] Depend on Figure 3Further analysis shows that the oblique line area 50 in the cross-sectional schematic diagram of the hot-rolled wide steel rolled by the upper roller 1 and the lower roller 2 is a deformation area, which has the following characteristics: the reduction in the middle of the cross-sectional area of ​​the hot-rolled wide steel is the largest; along the width direction, the reduction in the hot-rolled wide steel gradually decreases; and finally the upper and lower roller surfaces are out of contact with the hot-rolled wide steel. When the hot-rolled wide steel is rolled in the roller group, the reduction in the middle of the cross-sectional area of ​​the hot-rolled wide steel is the largest. After multiple rolling passes, the maximum reduction is 0.3 to 1 times the initial convexity of the hot-rolled wide steel.

[0041] Attached Figure 4 For attachment Figure 3 The enlarged view of area B is a schematic diagram of the force analysis of the contact surface between the convex roller and the hot-rolled wide strip along the cross section of the hot-rolled strip; the rolling force P in the deformation zone will generate a horizontal component force Pt along the width direction of the strip due to the roller convexity (curvature radius). This horizontal component force Pt is conducive to the movement of the metal material under rolling pressure in the width direction of the strip; and the smaller the curvature radius of the roller convexity, the greater the horizontal component force.

[0042] Attached Figure 5 It is a schematic cross-sectional view of a deformation zone formed by an upper roll, a lower roll and a strip steel when a second roll group rolls a hot-rolled wide strip steel after the first roll group has rolled the strip steel;

[0043] Depend on Figure 5 It can be seen that in the first rolling group rolling deformation zone, the upper roll crown contour line 11, the curvature radius R11 of the upper roll crown and the contour line 30 of the wide steel rolled piece; the distance between the boundary point where the upper roll crown contour line 11 contacts the contour line 30 on the cross section of the wide steel and the center line of the wide steel is W1; the second rolling group rolling is carried out after the first rolling group rolling is completed, and the distance between the boundary point where the upper roll crown contour line 21 of the second roll group, the curvature radius R21 of the upper roll crown and the contour line 30 on the cross section of the wide steel and the center line of the wide steel is W2; Figure 5 In the embodiment, the curvature radius R21 of the convexity of the rolls of the second roll group is greater than the curvature radius R21 of the convexity of the rolls of the first roll group, and the distance W2 between the boundary point where the rolls of the second roll group contact the strip and the center line of the strip is greater than the distance W1 between the boundary point where the rolls of the first roll group contact the strip and the center line of the strip.

[0044] Depend on Figure 5Further analysis shows that the rolling of the hot-rolled wide strip by the second roller group is carried out after the rolling of the first roller group; in this schematic diagram, the thinning amount of the strip thickness of the hot-rolled wide strip by the second roller group is zero; from the center line of the wide strip along the width direction of the strip, the thinning amount of the hot-rolled wide strip by the second roller group gradually increases; when the distance from the center line of the hot-rolled wide strip is W1, the thinning amount of the hot-rolled wide strip by the second roller group reaches the maximum value; along the width direction, from W1 to W2, the thinning amount of the hot-rolled wide strip by the second roller group decreases from the maximum value to zero. During the rolling process of the second roller group, the rollers of the second roller group start to contact the contour line of the hot-rolled wide strip from the point W1 away from the center line of the wide strip, and the contact point between the rollers of the second roller group and the contour line of the hot-rolled wide strip gradually moves along the width direction during the rolling process, and the rolling of the second roller group ends when the distance from the center line of the wide strip is W2.

[0045] Depend on Figure 5 Further analysis shows that the radius of curvature R21 of the roll crown of the second roll group is greater than the radius of curvature R11 of the roll crown of the first roll group; the rolls of the second roll group have a reduction in the cross-section of the wide strip when the thickness thinning of the center line of the cross-section of the wide strip is zero, and this reduction distribution is conducive to the movement of the pressed metal in the width direction.

[0046] Attached Figure 6 A schematic diagram of the longitudinal deformation zone of a roll group roll with different roll diameters when rolling a strip steel in a method for controlling the convexity of a strip steel provided by the present invention. Figure 6 It can be seen that under the same reduction, the contact arc length L2 between the large diameter roller R2 and the rolled piece is greater than the contact arc length L1 between the small diameter roller R1 and the rolled piece; Figure 4 The horizontal component of the rolling force when the large diameter roll R2 is rolling is smaller than the horizontal component of the rolling force when the small diameter roll R1 is rolling; therefore, the large diameter roll has a greater resistance to the flow of the pressed metal along the length direction of the strip, which is beneficial to the flow of the pressed metal along the width direction of the strip. In the method for controlling the crown of the strip provided by the present invention, it is recommended that the rolls of the roll group have a large roll diameter.

[0047] Figure 7 It is a schematic diagram of the assembly of the roller in the embodiment of the present invention; Figure 7 In the figure, the roll 5 is composed of a roll shaft 5.1 and a working roll ring 5.2. The roll shaft 5.1 and the working roll ring 5.2 are slidably connected. The working roll ring is slidably installed in the middle of the roll shaft. The diameter of the working roll ring 5.2 is larger than the diameter of other parts of the upper roll shaft. The outer periphery of the working roll ring 5.2 is a convex surface. When the working roll ring 5.2 is damaged or replaced with other models, the working roll ring 5.2 can slide out from the roll shaft 5.1 for easy replacement.

[0048] like Figures 8 to 11As shown, the hot-rolled strip slitting machine group 4 in this application includes an unwinder 41, a centering device 42, a pinch straightening device 43, a first rolling mill 44, a second rolling mill 45, a first looper pit 46, a slitting device 47, a second looper pit 48, an outlet clamping and tensioning device 49, and a coiler 410. It should be noted that, except for the roll group on the first rolling mill 44 and the second rolling mill 45, the rest of the equipment is prior art. Specifically:

[0049] Uncoiler 41: It is composed of an expansion and contraction reel, a reducer, a motor and a base, etc., and provides support and power for the opening and rotation of the strip; and the uncoiler 41 provides entry tension for the longitudinal shearing of the strip and the adjustment of crown rolling.

[0050] The centering device 42 is composed of a detection device, a hydraulic system and a control system; it works together with the uncoiler 41; its function is to ensure that the strip after uncoiling is always in the middle position of the longitudinal shear line; and to provide a guarantee for rolling the raised part in the middle of the cross section of the strip during subsequent rolling.

[0051] The clamping and straightening device 43 is composed of a guide plate, a clamping roller, a straightening roller, etc.; its function is to ensure that the strip head passes smoothly through the rolling mill and the first looper pit 46; when the rolling is put into operation, one of the important functions of the straightening roller is to stabilize the strip and limit its deviation.

[0052] The first rolling mill 44 and the second rolling mill 45: the rolling area is the core area of ​​the application of the present invention, including two rolling mills; each rolling mill includes a frame device, a roller system, a transmission device and a pressing device, etc.; due to the small deformation of the rolling mill of the present invention, a single working roll transmission can be adopted, and a scheme of simultaneous transmission of the upper and lower working rolls can also be adopted; tension rolling is adopted between the two rolling mills.

[0053] The first loop pit 46 works during the longitudinal shearing process and its function is to keep the strip in a tension-free state when it enters the longitudinal shearing unit.

[0054] The longitudinal shearing device 47 is composed of the longitudinal shearing device 47 and the edge trimming device. The function of the longitudinal shearing device 47 is to cut the hot-rolled steel strip into strips according to the width requirement. When the present invention is working, the longitudinal shearing device 47 is in the longitudinal shearing working state of the middle shearing, that is, a steel strip is cut from the middle into two symmetrical steel strips.

[0055] The second looping pit 48 provides storage space for the strip steel after longitudinal shearing and stripping when the lengths of the strip steel strips are different.

[0056] The outlet clamping and tensioning device 49 is composed of a clamping plate and a tensioning roller, etc., and provides post-tensioning force for the strip coiling after stripping.

[0057] Coiling machine 410: It is composed of an expansion and contraction reel, a reducer, a motor, etc.; its function is to roll the strip steel into a plurality of steel coils after being slit, and when the present invention is used, it is rolled into two steel coils.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the convexity of hot-rolled wide strip steel, characterized in that: The following steps are involved: The hot-rolled wide strip is rolled by multiple groups of rollers, the contact width between the rollers and the cross section of the hot-rolled wide strip is smaller than the width of the hot-rolled wide strip, the contact area between the rollers and the cross section of the strip is located in the middle of the cross section of the wide strip, and the area with the largest convexity of the cross section of the hot-rolled wide strip is locally pressed down; the amount of pressing down of the hot-rolled wide strip by the rollers is smaller than the convexity of the cross section of the hot-rolled wide strip; the rollers of the multiple groups of rollers are convex rollers, and the convexity radii of curvature of the rollers of different roller groups are different, wherein the rollers in each group of rollers have a preset convexity curvature radius, and along the rolling direction of the strip, the convexity radii of curvature of the rollers of the subsequent roller groups gradually increase; the thinning amount of the strip thickness of the center line of the hot-rolled wide strip by the rollers of the second roller group is zero; The contact width between the roller and the cross section of the strip is 10% to 30% of the width of the hot-rolled wide strip; and the contact area between the roller and the cross section of the strip is located in the middle of the cross section of the hot-rolled wide strip; The hot-rolled wide strip steel coil is first treated by the above method, and then cut into two medium and wide strip steel coils with equal widths in a longitudinal shearing unit, and then pickled and rolled in a medium and wide strip steel cold rolling mill.

2. A method for controlling the crown of hot-rolled wide strip steel according to claim 1, characterized in that: When multiple groups of rollers are used to roll hot-rolled wide strips, the reduction in thickness of the hot-rolled wide strips at the contact portion between the rollers and the strip is not greater than the original convexity of the hot-rolled wide strips.

3. A method for controlling the crown of hot-rolled wide strip steel according to claim 1, characterized in that: The reduction in thickness of the hot-rolled wide strip steel at the contact portion between the roller and the strip steel is 30% to 100% of the original convexity of the hot-rolled wide strip steel.

4. A method for controlling the crown of hot-rolled wide strip steel according to claim 1, characterized in that: Multiple groups of rollers are used to roll hot-rolled wide strips, and each group of rollers uses crowned rollers. The crown curvature radius of each group of rollers is related to the original crown, width and thickness of the hot-rolled strip.

5. A method for controlling the crown of hot-rolled wide strip steel according to claim 1, characterized in that: Each group of the roller sets includes an upper roller and a lower roller, and the upper roller and the lower roller have the same structure; Wherein, the middle part of the upper roll shaft and the middle part of the lower roll shaft are both connected with the working roll ring, and the working roll ring and the roll shaft are connected by a key.

6. A method for controlling the crown of hot-rolled wide strip steel according to claim 5, characterized in that: When the working roll ring is damaged or the product is replaced, the old working roll ring can be slid out from the roll shaft, and the new working roll ring can be easily slid in.

7. A method for controlling the crown of hot-rolled wide strip steel according to claim 5, characterized in that: The upper roller and the lower roller are single roller transmission.

8. A method for controlling the crown of hot-rolled wide strip steel as claimed in claim 5, characterized in that: The upper roller and the lower roller are double roller transmission.

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