JP2002066619A - Cold rolling method for steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold rolling method for a steel strip capable of obtaining an excellent steel strip having high accuracy in thickness, inhibiting the occurrence of a sheet deviation and an asymmetric edge drop. SOLUTION: A rolling mill is the one that comprises a means for adjusting an angle between the direction that forms a right angle against the rolling direction in a face parallel with a rolling face and the axial direction of a vertical operation roll, and a means for adjusting an amount of a reduction that acts on both sides of the vertical operation roll. Each amount of a reduction of both sides is individually adjusted so that a thickness profile of a rolling material of an outlet side of the rolling mill shall be symmetric based on a thickness profile of a rolling material of an inlet side of the rolling mill. Then, the angle is so adjusted for rolling as to prevent the occurrence of a sheet deviation based on a deviation of the rolling material of the outlet side of the rolling mill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cold rolling a steel strip capable of stably obtaining a steel strip having good thickness accuracy. More specifically, the present invention relates to a method for cold rolling a steel strip capable of obtaining a steel strip having good thickness accuracy while suppressing sheet leaning.

[0002]

2. Description of the Related Art Generally, a hot-rolled steel strip is formed with a strip crown having a convex portion substantially at the center in the strip width direction.
Further, an asymmetric thickness distribution called a wedge in which the thickness changes substantially linearly in the width direction may be formed.

[0003] When a hot-rolled steel strip (hereinafter, also referred to as a base material) is subjected to cold rolling, a profile called an edge drop in which the thickness is sharply reduced at a width end portion is formed. Further, if a wedge is present in the base material, edge drops formed at both ends of the plate become asymmetrical in the left and right directions, and the accuracy of the plate thickness is deteriorated.

[0004] Therefore, in cold rolling, in order to reduce the thickness difference between the center portion and the end portion of the plate width and to improve the plate thickness accuracy, it is necessary to use a steel strip to be subjected to cold rolling. It is necessary to perform edge drop control for the left and right sides in consideration of the asymmetrical thickness distribution of a certain base material. Hereinafter, the edge drop control is also referred to as asymmetric edge drop control.

As a method of the asymmetric edge drop control, there are known a method of adjusting the rolling amount of the rolling mill in the left and right direction, a method of adjusting the left and right roll bending force, and a method of shifting the upper and lower work rolls.

Japanese Patent Application Laid-Open No. 57-50206 discloses a control method in which rolling is performed by individually adjusting roll bending forces acting on the left and right sides of a work roll. Japanese Patent Application Laid-Open No. 8-90032 discloses that upper and lower work rolls (work rolls) can be shifted in opposite directions in the axial direction, a shift distance for correcting an edge drop is calculated, and each of the upper and lower work rolls is adjusted. The rolling method is disclosed in which the shift speed is controlled so that the shift time becomes equal.

[0007]

By the way, when the asymmetric edge drop control is performed, the distribution of the elongation of the material to be rolled becomes asymmetrical left and right, so that the speed of the material to be rolled before and after the rolling tool part is slightly different between the left and right. As a result, board leaning occurs. In other words, a leaning occurs such that the material to be rolled escapes from the strong reduction side having a large reduction amount to the light reduction side having a small reduction amount.

[0008] Once the sheet leaning occurs, generally the left-right asymmetry of the rolling state increases, and the sheet leaning further proceeds. If the sheet leans significantly, it becomes difficult to continue the rolling operation. Performing asymmetric edge drop control by adjusting the left and right reduction amount,
The occurrence of the above-mentioned board leaning is remarkable. For this reason, the adjustment of the left-right reduction amount has been used not as a control means of the asymmetric edge drop but as a board deviation correcting means.

In the method of individually adjusting the roll bending force disclosed in Japanese Patent Application Laid-Open No. 57-50206, the asymmetrical rolling region generated by individually adjusting the roll bending force is limited to the vicinity of the end of the sheet width. The influence on the board lean is not as great as that by the method of adjusting the amount of reduction in the right and left. However, this method has a drawback that the effect of the asymmetric edge drop control is remarkably reduced when slight board deviation occurs, and there is a problem that sufficient control accuracy cannot be obtained.

Japanese Patent Application Laid-Open No. Hei 8-90032 discloses that the occurrence of meandering (board shift) is suppressed by equalizing the shift operation time of the work roll.
When there is a difference in the shift operation time when the work roll shifts in the opposite direction, the material to be rolled is dragged by the roll and meanders, a phenomenon peculiar to the shift rolling mill, and the transient that occurs only when the shift position is changed It merely shows how to deal with the meandering phenomenon. Therefore, Japanese Patent Application Laid-Open No. 8-9003
According to the method disclosed in Japanese Patent Publication No. 2 (1994), it is difficult to suppress the leaning caused by the left-right asymmetric rolling.

An object of the present invention is to provide a method of cold rolling a steel strip which can suppress the occurrence of asymmetric edge drop and obtain a steel strip having a good thickness accuracy while suppressing the leaning of the steel strip. is there.

[0012]

In order to suppress the leaning of the steel strip, a method of adjusting the amount of reduction in the right and left direction is generally performed. However, the asymmetrical edge is adjusted by adjusting the roll bending force or adjusting the roll shift. When used together with the drop control, the effect of improving the asymmetric edge drop becomes extremely small.

Further, a method of preventing the leaning of the plate by using a plate-shaped or roller-shaped side guide is conceivable. However, when the thickness is small, deformation such as lifting of the steel strip at the contact portion occurs, and the leaning preventing effect is obtained. Is not enough.

Therefore, the present inventor has paid attention to a method of deflecting the axes of the upper and lower work rolls in a horizontal plane from a direction perpendicular to the rolling direction as a countermeasure for suppressing the leaning of the plate. Hereinafter, this method is also referred to as a roll axis deflection method, and the board shift control by this method is also referred to as a roll axis deflection control.

FIG. 1 is a schematic plan view for explaining a roll axis deflecting method. FIG. 1A shows a case where upper and lower work rolls do not intersect, and FIG. Represents the case. Reference numeral 1 denotes a material to be rolled, and 2 denotes a work roll.

As shown in FIG. 1A, in the roll axis deflection method, the axial direction (line A) of the upper and lower work rolls 2 is perpendicular to the rolling direction in a plane parallel to the rolling surface (line B). ), The frictional force acting between the work roll 2 and the material 1 to be rolled has a component in the width direction of the plate, and the component is applied in a direction opposite to the direction of the plate to correct the deviation. It is assumed that. Hereinafter, the angle between the direction perpendicular to the rolling direction and the axial direction of the upper and lower work rolls in a plane parallel to the rolling surface is also referred to as a deflection angle.

As shown in FIG. 1B, even when the upper and lower work rolls 2 and 2 intersect, the average direction (line A) of the upper and lower work roll axes is perpendicular to the rolling direction in the horizontal plane. By deflecting from the direction (line B), it is possible to correct the board deviation as in the case where the upper and lower work rolls do not intersect. In this case, the deflection angle is the angle between the direction perpendicular to the rolling direction and the average direction of the upper and lower work roll axes in a plane parallel to the rolling surface.

This roll axis deflection method has a small effect on asymmetric edge drop control. Therefore, by simultaneously applying the roll axis deflection control and the asymmetric edge drop control such as the adjustment of the left and right reduction amount and the adjustment of the roll bending force, the base material having the left and right asymmetrical thickness profile can be obtained while suppressing the sheet leaning. It has been found that the steel strip can be rolled into a strip having a symmetrical thickness profile.

Since the effect of preventing deviation of the plate by the roll axis deflection control depends on the frictional force between the work roll shaft and the material to be rolled, the greater the roughness of the work roll or the steel strip, the more advantageous.
However, when the roll roughness is excessive, there is a problem that the rolling load increases or the change in roughness becomes large and rolling becomes unstable. Therefore, the roughness of the work roll is 0.1
It is preferable that the thickness be not less than μm and not more than 1.0 μm.

In the asymmetric edge drop control, the controllable range of the thickness profile increases as the thickness of the material to be rolled increases. Therefore, the roll axis deflection control and the asymmetric edge drop control are preferably applied to an initial cold rolling pass composed of a plurality of rolling passes.

The present invention has been completed based on the above findings, and the gist thereof is as follows. (1) Means for adjusting the angle between the direction perpendicular to the rolling direction in the plane parallel to the rolling surface and the axial direction of the upper and lower work rolls, and the amount of reduction applied to the left and right of the upper and lower work rolls A cold rolling method for a steel strip by a rolling mill comprising: a sheet thickness of a material to be rolled at an outlet side of the rolling mill based on a thickness profile of a material to be rolled at an inlet side of the rolling mill. The right and left reduction amounts are individually adjusted so that the profile becomes symmetrical, and further, based on the leaning of the material to be rolled on the outlet side of the rolling mill, the angle is adjusted so that the leaning does not occur. And cold rolling the steel strip.

(2) means for adjusting the angle between the direction perpendicular to the rolling direction in the plane parallel to the rolling surface and the axial direction of the upper and lower work rolls, and rolls acting on the left and right of the upper and lower work rolls Cold rolling method of a steel strip by a rolling mill with means for adjusting the bending force,
The left and right roll bending forces are individually adjusted so that the thickness profile of the material to be rolled on the exit side of the rolling mill is symmetrical on the basis of the thickness profile of the material to be rolled on the entrance side of the rolling mill, Furthermore, a cold rolling method for a steel strip, comprising: performing cold rolling by adjusting the angle so that the sheet lean does not occur, based on the sheet lean of the material to be rolled on the exit side of the rolling mill. .

(3) Means for adjusting the angle between the direction perpendicular to the rolling direction in the plane parallel to the rolling surface and the axial direction of the upper and lower work rolls, and adjusting the axial position of the upper and lower work rolls And a cold rolling method of a steel strip by a rolling mill provided with a tapered portion so that one end diameter located on the opposite side of the upper and lower work rolls is smaller than the diameter of the central portion. The axial position of the upper and lower work rolls is adjusted so that the thickness profile of the material to be rolled on the output side of the rolling mill is bilaterally symmetric based on the thickness profile of the material to be rolled on the entrance side of the rolling mill. Individually adjusting, further, based on the leaning of the material to be rolled on the exit side of the rolling mill, cold rolling by adjusting the angle so that the leaning does not occur. Cold rolling method.

(4) The method according to any one of the above items (1) to (3), wherein the cold rolling is performed in a first rolling pass and / or a second rolling pass of a plurality of rolling passes. A method for cold rolling a steel strip as described.

(5) The rolling mill is at least one of a first stand and a second stand from upstream to downstream of a tandem rolling mill row in which a plurality of stands are arranged in tandem. The method for cold rolling a steel strip according to any one of the above items (1) to (3), characterized in that:

(6) The surface roughness of the upper and lower work rolls is R
The cold rolling method according to any one of the above items (1) to (5), wherein a is from 0.1 μm to 1.0 μm.

[0027]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Hereinafter, means for adjusting the angle between the direction perpendicular to the rolling direction in the plane parallel to the rolling surface and the axial direction of the upper and lower work rolls, and adjusting the amount of reduction acting on the left and right sides of the upper and lower work rolls means,
Means for adjusting the roll bending force acting on the left and right of the upper and lower work rolls, and means for adjusting the axial position of the upper and lower work rolls, respectively, a roll axis deflecting means, a left and right reduction amount adjusting means, a left and right roll bending force adjusting means Also referred to as axial position adjusting means.

FIG. 2 is a schematic plan view illustrating an example of the roll axis deflecting means of the rolling mill according to the present embodiment. In the figure, reference numeral 1 denotes a material to be rolled, 2 denotes a work roll, 3 denotes a work roll shaft box, 4 denotes a housing post, 5 denotes a rolling mill, 6
Represents a hydraulic cylinder.

As shown in FIG. 2, the rolling mill 5 comprises upper and lower work rolls 2, work roll axle boxes 3, 3 for supporting the shaft ends of the work rolls, and housing posts 4, 4, 4, 4. A hydraulic cylinder 6,6,6,6 having one end mounted on the housing post and the other end mounted on the work roll shaft box, and a deflection angle control device 7 for adjusting the stroke of the hydraulic cylinder and controlling the deflection angle. Roll axis deflecting means.

In this rolling mill, the position of the work roll axle boxes 3, 3 in the rolling direction is shifted right and left by adjusting the stroke of the hydraulic cylinder by the deflection angle control device 7, so that the position in the plane parallel to the rolling surface is adjusted. The deflection angle, which is the angle between the direction perpendicular to the rolling direction and the axial direction of the upper and lower work rolls, can be adjusted.

When the axial thrust force acting between the work roll and the reinforcement roll that reinforces the work roll increases, the reinforcement roll may be deflected in the same manner as the work roll.

In the embodiment shown in FIG. 2, the work roll itself is rotated, but the deflection angle can also be adjusted by rotating the rolling mill body in a plane parallel to the rolling surface.

FIG. 3 is a schematic diagram for explaining a method for adjusting the horizontal reduction of the rolling mill according to the present embodiment. 2 are denoted by the same reference numerals. Reference numeral 8 denotes a reinforcing roll. As shown in FIG. 3, the rolling mill 5 adjusts the hydraulic cylinders 9, 9 provided on the left and right sides of the rolling mill and the strokes of the hydraulic cylinders as left and right rolling amount adjusting means to individually control the left and right reduction amounts. And a reduction amount control device 10.

In this rolling mill, the right and left reduction amounts of the work rolls can be individually controlled by adjusting the strokes of the hydraulic cylinders 9 by the reduction amount control device 10. FIG. 4 is a schematic diagram illustrating a method for adjusting the roll bending force of the rolling mill according to the present embodiment. 2 and 3 are denoted by the same reference numerals.

As shown in FIG. 4, the rolling mill 5 adjusts the strokes of the hydraulic cylinders 11 provided at both ends of the work rolls as left and right roll bending force adjusting means and the hydraulic cylinders to adjust the right and left. A roll bending force control device 12 for individually controlling the roll bending force.

In the rolling mill 5, the right and left roll bending forces can be individually controlled by adjusting the strokes of the hydraulic cylinders 11 by the roll bending force control device 12.

FIG. 5 is a schematic diagram for explaining a method of adjusting the axial position of the work roll of the rolling mill according to the present embodiment. 2 and 3 are denoted by the same reference numerals. As shown in FIG. 5, the rolling mill 5 adjusts the stroke of the hydraulic cylinders 13, 13 provided at the ends of the upper and lower work rolls as axial position adjusting means and adjusts the strokes of the upper and lower work rolls 2,
And a roll shift controller 14 for individually controlling the two axial positions. Further, the upper and lower work rolls 2 and 2 have tapered portions formed such that the diameter of one end located on the side opposite to the upper and lower work rolls is smaller than the diameter of the center.

In this rolling mill, the roll shift control device 1
By adjusting the strokes of the hydraulic cylinders 13 at 13, the axial positions of the upper and lower work rolls 2 can be individually controlled.

It should be noted that the roll axis deflecting means can also be installed without interfering with the right and left reduction amount adjusting means, the left and right roll bending force adjusting means, and the axial position control means in terms of equipment structure.

As a rolling mill according to the present embodiment, a four-high rolling mill comprising a working roll and a reinforcing roll has been described as an example in FIGS. 3 to 5, but an intermediate roll is provided between the working roll and the reinforcing roll. It can be a six-high rolling mill.

The rolling mill according to the present embodiment is configured as described above. Next, a method of performing cold rolling on a material to be rolled as a steel strip by a rolling mill provided with a roll axis deflecting means and a right and left reduction amount adjusting means will be described with reference to FIGS.

The thickness profile of the material to be rolled on the entry side of the rolling mill is measured, and the reduction amount control is performed based on the measured thickness profile so that the thickness profile of the material to be rolled on the exit side of the rolling mill becomes symmetrical. The set values of the left and right reduction amounts are calculated by the device 10, and the hydraulic cylinders 9 and
Adjust stroke 9 individually. Furthermore, the amount of deviation of the material to be rolled on the exit side of the rolling mill, that is, the distance between the center line in the width direction of the rolling mill and the center line in the width direction of the material to be rolled is calculated or measured so that the deviation does not occur. The deflection angle controller 7 calculates a set value of the deflection angle, and adjusts the strokes of the hydraulic cylinders 6, 6, 6, and 6 so that the set value is obtained.

If the rigidity of the rolling mill and the distance from the equipment before and after the rolling mill (for example, adjacent rolling mills) are kept constant, the thickness of the sheet accompanying the adjustment of the horizontal rolling reduction is mainly determined by the thickness profile on the entry side of the rolling mill. , The width direction distribution of the elongation of the material to be rolled determined by the set value of the amount of lateral reduction, etc., and the dimensions of the material to be rolled, the plate slip restraining force determined by the tension on the entrance and exit sides, these factors and the sheet If the relationship with the shift amount is formulated in advance, it can be obtained by calculation.

The influence of the roll axis deflection on the sheet deviation is obtained mainly from the relationship between the width direction force determined by the deflection angle and the rolling frictional force and the sheet deviation suppressing force determined by the dimensions of the material to be rolled, the entrance and exit side tension, and the like. . The rolling friction force depends on the cumulative rolling distance, rolling speed, rolling load, and the like as an index of roll wear.
Therefore, the deflection angle with respect to the board shift amount to be suppressed or corrected can be calculated by preparing a relational expression using the above factors as coefficients.

Further, the amount of board lean accompanying the adjustment of the horizontal reduction amount is
It can be determined by measurement using a plate deviation meter provided on the exit side of the rolling mill. As the board-side meter, there is an optical-type or magnetic-side board-side meter. Further, it is also possible to detect both ends of the plate width by using a plate thickness profile meter and also serve as a plate deviation meter.

As described above, the right and left reduction amount is adjusted by the right and left reduction amount adjusting means, and the deflection angle is adjusted by the roll axis deflecting means, and the rolled material is cold-rolled, so that the occurrence of the sheet leaning is reduced. The occurrence of the asymmetric edge drop can be suppressed while suppressing the occurrence.

Next, a method of performing cold rolling on a steel strip as a material to be rolled by a rolling mill having roll axis deflection means and right and left roll bending force adjusting means will be described with reference to FIGS. .

The thickness profile of the material to be rolled on the entry side of the rolling mill is measured, and the roll is set so that the thickness profile of the material to be rolled on the exit side of the rolling mill is symmetrical based on the measured thickness profile. The bending force control device 12 calculates the set values of the left and right roll bending forces, and individually adjusts the strokes of the hydraulic cylinders 11 so that the set values are obtained. Further, the deviation of the material to be rolled on the exit side of the rolling mill is calculated or measured, and a deflection angle control device calculates a deflection angle set value so that the deflection does not occur, and the liquid is adjusted so that the set value is obtained. Pressure cylinder 6,6,6
Adjust the stroke of 6.

If the rigidity of the rolling mill and the distance from the equipment before and after the rolling mill (for example, adjacent rolling mills) are constant, the thickness of the sheet at the entry side of the rolling mill is mainly determined by the amount of leaning accompanying the adjustment of the right and left roll bending forces. It occurs in the relationship between the width distribution of the elongation of the material to be rolled determined by the profile, the set value of the left and right roll bending force, etc., and the plate slippage suppressing force determined by the size of the material to be rolled and the entrance and exit side tension. If the relationship between the distance and the board shift amount is formulated in advance, it can be obtained by calculation.

The influence of the roll axis deflection on the board deviation is determined from the relationship between the width direction force and the board deviation suppressing force as described above. Accordingly, as described above, the deflection angle with respect to the board deviation amount to be suppressed or corrected is obtained by calculation by preparing in advance a relational expression in which the factors influencing the width direction force and the board deviation suppression force are coefficients. be able to.

Further, the amount of sheet deviation accompanying the right and left roll bending force adjustment can be obtained by measurement using a sheet deviation meter provided on the rolling mill exit side. As the board-side meter, there is an optical-type or magnetic-side board-side meter. Further, it is also possible to detect both ends of the plate width by using a plate thickness profile meter and also serve as a plate deviation meter.

As described above, the right and left roll bending forces are adjusted by the right and left roll bending force adjusting means, and the deflection angle is further adjusted by the roll axis deflecting means. The occurrence of asymmetric edge drop can be suppressed while suppressing the occurrence.

Next, a method of performing cold rolling on a steel strip by a rolling mill having roll axis deflection means and axial position adjusting means will be described with reference to FIGS. The roll shift control device 14 measures the thickness profile of the material to be rolled on the entry side of the rolling mill, and based on the measured thickness profile, the thickness profile of the material to be rolled on the exit side of the rolling mill is symmetrical. The set value of the axial position of the upper and lower work rolls 2 and 2 is calculated, and the hydraulic cylinders 13 and
13 strokes are individually adjusted. Further, the deviation of the material to be rolled on the exit side of the rolling mill is measured, and the deflection angle control device 7 calculates a set value of the deflection angle so that the deviation does not occur. 6,6
Adjust the stroke of 6,6.

If the rigidity of the rolling mill and the distance to the equipment before and after the rolling mill (for example, adjacent rolling mills) are fixed, the amount of leaning accompanying the adjustment of the axial position of the upper and lower work rolls is mainly determined at the entrance to the rolling mill. The width profile of the elongation of the material to be rolled, which is determined from the set value of the sheet thickness profile, the axial position, and the like, and the dimensions of the material to be rolled, which are generated in the relationship between the sheet leaning suppression force determined by the tension on the entrance and exit sides. If the relationship between the factor and the board shift amount is formulated in advance, it can be obtained by calculation.

The influence of the roll axis deflection on the board deviation is determined from the relationship between the width direction force and the board deviation suppressing force as described above. Accordingly, as described above, the deflection angle with respect to the board deviation amount to be suppressed or corrected is obtained by calculation by preparing in advance a relational expression in which the factors influencing the width direction force and the board deviation suppression force are coefficients. be able to.

The amount of board deviation accompanying the axial position adjustment is as follows:
It can be determined by measurement using a plate deviation meter provided on the exit side of the rolling mill. As the board-side meter, there is an optical-type or magnetic-side board-side meter. Further, it is also possible to detect both ends of the plate width by using a plate thickness profile meter and also serve as a plate deviation meter.

As described above, the axial position of the upper and lower work rolls is adjusted by the axial position adjusting means, the deflection angle is adjusted by the roll axis deflecting means, and the material to be rolled is cold-rolled. While suppressing the occurrence of asymmetric edge drop.

When the deflection angle of the roll axis deflecting means according to the present invention is within ± 1 °, a sufficient board deviation correcting effect can be obtained. For example, if the distance between the left and right work roll axle boxes is 2
In the case of a 500 mm rolling mill, if the difference between the rolling direction positions of the left and right work roll axle boxes is 43.6 mm on the left and right, the deflection angle is 1
Deflection in degrees is possible.

The means for adjusting the right and left rolling reduction, the right and left roll bending force, and the axial position adjustment used as the asymmetric edge drop control means all function independently. The effect can be increased.

The cold rolling method of the present invention is more effective as the sheet thickness of the material to be rolled is larger in terms of the asymmetric edge drop control effect and the sheet offset correction effect. Therefore, when the cold rolling includes a plurality of rolling passes, the cold rolling method of the present invention is desirably performed in the first rolling pass or the second rolling pass of the plurality of rolling passes. When the asymmetry of the sheet thickness profile is large, it is preferable to perform the process in both the first rolling pass and the second rolling pass, and it is also preferable to perform the process in the subsequent rolling pass.

When cold rolling is performed by a tandem rolling mill row in which a plurality of stands are arranged in tandem, a rolling mill that implements the cold rolling method of the present invention is arranged from upstream to downstream of the tandem rolling mill row. It is desirable to use the first stand and the second stand. If facilities such as pinch rolls and bridle rolls, which have a binding force against the steel strips provided on the entry side of the tandem rolling mill row, are far away from the first stand, the first stand may be moved out of the first stand. There is a risk that the sheet leaning behavior on the side may become unstable, and the rolling mill according to the present invention is preferably applied to the second and subsequent stands.

The roughness of the work roll according to the present invention is desirably not less than 0.1 μm and not more than 1.0 μm in Ra. R
If a is 0.1 μm, the effect of preventing roll deviation by roll axis deflection control may be insufficient.
Rolling may become unstable.

[0063]

FIG. 6 is a schematic diagram showing a row of tandem rolling equipment used for investigating the effect of the present invention. This tandem rolling equipment row is composed of five rolling mill stands (Nos. 1 to 5) having a work roll diameter of 400 mm, a reinforcing roll diameter of 1500 mm, and a body length of 1800 mm.

Using this tandem rolling equipment line, a base material of low carbon steel having an asymmetrical thickness profile having a thickness of 4.0 mm at the center of the width and a thickness difference of 0.05 mm between both ends of the width. Was cold-rolled into a steel strip having a thickness of 0.8 mm. that time,
The first stand of the tandem rolling equipment line (No. 1)
A rolling mill equipped with roll axis deflection means and right and left roll bending force adjusting means is arranged in a direction in which the work roll axle box on the thin side of the base material thickness of the work roll relatively moves to the rolling exit side. Roll axis deflection control for deflecting at a deflection angle of 0.36 °, and asymmetrical edge drop control in which the left and right roll bending forces are adjusted to 60 ton and the other roll bending force to 0 ton by the left and right roll bending force adjusting means. And the thickness profile after rolling and N
o. Investigation was made on the situation of the approaching board on the exit side of one stand. As a comparative example, a test was also performed in which the roll axis deflection control was not performed and only the asymmetric edge drop control by the right and left bending force adjusting means was performed.

FIG. 7 is a graph showing the thickness profile on the exit side of the tandem rolling mill. The solid line represents the example of the present invention, and the broken line represents the comparative example. In the example of the present invention, the roll axis deflection control was performed. The amount of deviation of the material to be rolled on the exit side of one stand is suppressed to 10 mm or less, and the thickness profile after rolling is substantially symmetrical as shown in FIG. 7, and the minimum thickness in the width direction is the same as that of the comparative example. 0.760mm to 0.785m
m to 0.025 mm. Further, in the comparative example, No. 1 was not rolled during the rolling. The amount of board lean at the exit side of one stand is 100
The rolling operation was stopped because the diameter exceeded mm.

[0066]

According to the present invention, when a base material having an asymmetrical thickness profile is cold-rolled, it is possible to suppress the occurrence of asymmetrical edge drop while suppressing the occurrence of sheet leaning. Excellent effects such as improved thickness accuracy and improved rolling stability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view for explaining a roll axis deflection method. FIG. 1 (a) shows a case where upper and lower work rolls do not intersect, and FIG. 1 (b) shows a case where upper and lower work rolls intersect. Represent.

FIG. 2 is a schematic plan view illustrating an example of a roll axis deflection unit of the rolling mill according to the embodiment.

FIG. 3 is a schematic diagram illustrating a method for adjusting a horizontal rolling reduction of a rolling mill according to the embodiment.

FIG. 4 is a schematic diagram illustrating a method for adjusting the roll bending force of the rolling mill according to the embodiment.

FIG. 5 is a schematic diagram illustrating a method for adjusting the axial position of a work roll of the rolling mill according to the embodiment.

FIG. 6 is a schematic view showing a tandem rolling equipment row used for investigating the effect of the present invention.

FIG. 7 is a graph showing a thickness profile on a tandem rolling mill row exit side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolled material 2 Work roll 3 Work roll shaft box 4 Housing post 5 Rolling machine 6, 9, 11, 13: Hydraulic cylinder 7: Deflection angle control device 8: Reinforcement roll 10: Reduction amount control device 12: Roll bending force Control device 14: Roll shift control device

Claims (6)

[Claims] 1. A means for adjusting an angle between a direction perpendicular to a rolling direction in a plane parallel to a rolling surface and an axial direction of an upper and lower work roll, and a reduction amount acting on the left and right sides of the upper and lower work rolls. And a means for adjusting the cold rolling of a steel strip by a rolling mill, comprising: a rolled material on an output side of the rolling mill based on a thickness profile of a material to be rolled on an input side of the rolling mill. The left and right reduction amounts are individually adjusted so that the sheet thickness profile is symmetrical, and further, based on the sheet lean of the material to be rolled on the exit side of the rolling mill,
A cold rolling method for a steel strip, wherein the cold rolling is performed by adjusting the angle so that the leaning does not occur. 2. A means for adjusting an angle between a direction perpendicular to a rolling direction in a plane parallel to a rolling surface and an axial direction of upper and lower work rolls, and roll bending acting on the left and right of the upper and lower work rolls. Cold rolling method for a steel strip by means of a rolling mill provided with a means for adjusting the force, wherein the material to be rolled on the outlet side of the rolling mill based on the thickness profile of the material to be rolled on the inlet side of the rolling mill. The left and right roll bending forces are individually adjusted so that the sheet thickness profile becomes symmetrical, and further, based on the sheet leaning of the material to be rolled on the exit side of the rolling mill, the sheet leaning does not occur. A cold rolling method for a steel strip, wherein the angle is adjusted to perform cold rolling. 3. A means for adjusting an angle between a direction perpendicular to a rolling direction in a plane parallel to a rolling surface and an axial direction of the upper and lower work rolls, and adjusting an axial position of the upper and lower work rolls. A cold rolling method of a steel strip by a rolling mill further comprising a taper portion such that one end of the upper and lower work rolls located on opposite sides is smaller in diameter than the center. The axial positions of the upper and lower work rolls are individually determined such that the thickness profile of the material to be rolled on the output side of the rolling mill is bilaterally symmetric based on the thickness profile of the material to be rolled on the input side of the rolling mill. And then
A cold rolling method for a steel strip, comprising: performing cold rolling by adjusting the angle so that the sheet lean does not occur, based on the sheet lean of the material to be rolled on the exit side of the rolling mill. 4. The steel strip according to claim 1, wherein the cold rolling is performed in a first rolling pass and / or a second rolling pass of a plurality of rolling passes. Rolling method. 5. The method according to claim 1, wherein the rolling mill is at least one of a first stand and a second stand from upstream to downstream in a tandem rolling mill row in which a plurality of stands are arranged in tandem. The method for cold rolling a steel strip according to any one of claims 1 to 3, wherein: 6. The cold rolling method according to claim 1, wherein the surface roughness of the upper and lower work rolls is 0.1 μm or more and 1.0 μm or less in Ra.