JP2001137927A - Method for cold-rolling metal plate with cluster mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold-rolling method of a metal plate with a cluster mill with which composite elongation is eliminated and the shape of the plate is improved over the entire length of a coil. SOLUTION: Before applying rolling to the metal plate with a rolling mill, a position to be shifted is set by moving upper and lower work rolls so that the position of a taper starting end is in a prescribed distance inward from the edges of the metal plate. After applying rolling to the metal plate with the rolling mill, the metal plate is made into the target shape by manipulating the extrusion of a divided back-up roll and/or a bender for an intermediate roll in accordance with the change of the shape of the metal plate in 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 sheet material in a cluster type rolling mill using small-diameter work rolls, and in particular, to eliminate a composite elongation of the sheet material and obtain a sheet material having a good shape over the entire length of a coil. The present invention relates to a cold rolling method for a sheet material in a cluster type rolling mill capable of performing the method.

[0002]

2. Description of the Related Art When rolling a sheet material having a high deformation resistance, such as a stainless steel plate, in order to reduce the rolling load, generally, a 12-stage cluster shown in FIGS. A rolling mill is used. Small-diameter work rolls with a diameter of 150 mm or less have low bending stiffness and are easy to bend. Shape control characteristics of stainless steel rolling mills ”, Sumitomo Metals, 46-5, 1994), even if it is attempted to control the plate shape by using shape control means such as extrusion of backup rolls and intermediate roll benders, work rolls will be higher order. As a result, there is a problem that a composite elongation as shown in FIG. 8 occurs and a threading trouble such as drawing or breaking is likely to occur.

Japanese Patent Application Laid-Open No. Hei 8-90008 discloses that in the cluster type rolling mill shown in FIGS. 1 and 2, one end of the peripheral surface of the upper and lower work rolls 1 and 1 is tapered so as to be tapered. As shown in FIG. 1, a method is disclosed in which the upper and lower work rolls 1 and 1 are incorporated, and the upper and lower work rolls 1 and 1 are moved in the axial direction to perform cold rolling while suppressing shape defects.

However, in Japanese Unexamined Patent Publication No. Hei 8-90008, since the set position and the taper of the tapered portions 1T and 1B shown in FIG.
Even if the shape is controlled using the backup roll extrusion or the shape control means of the intermediate roll bender, there is a problem that the shape of the coil is defective at the tip end, and that the composite elongation cannot be suppressed over the entire length of the coil.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art, and to provide a cluster type rolling mill capable of eliminating composite elongation over the entire length of a coil and improving the shape of a sheet material. An object of the present invention is to provide a method for cold rolling a sheet material.

[0006]

That is, according to the present invention, there is provided a rolling mill in which one end of each of upper and lower work rolls is provided with a tapered taper so that the taper is vertically opposite to each other. Incorporated, the upper and lower work rolls are moved in the axial direction, the cold rolling method of the plate material in a cluster-type rolling mill that rolls the plate material while controlling the shape, before rolling the plate material in the rolling mill, The shift position is set by moving the upper and lower work rolls so as to be a predetermined distance inward from the plate edge of the plate material, and after the plate material is rolled by the rolling mill, a change in the shape of the plate material of the rolling mill is performed. A cold rolling method for a sheet material in a cluster-type rolling mill, in which a backup roll is extruded and / or an intermediate roll bender is operated to obtain a target shape.

According to a second aspect of the present invention, the diameter of the upper and lower work rolls is 150 mm or less, and the taper is 1 / 2500-
The cold rolling of a sheet material in a cluster type rolling mill according to claim 1, wherein the distance from the sheet edge of the sheet material to the tapered cutting start end is set to 100/350 mm or less. It is an invention of a method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The cold rolling method of the present invention
This will be described with reference to FIGS. FIG. 1 is used in the present invention
FIG. 2 is a schematic front view showing a roll layout of a 12-high cluster type rolling mill, and FIG. 2 is a side view of the cluster type rolling mill shown in FIG. FIG. 3 is a schematic view showing the shape of a work roll used in the present invention. FIG. 4 is a shape control block diagram of a 12-high cluster type rolling mill used in the present invention.

Here, 1 is a work roll, 1T and 1B are tapered portions, 2 is an intermediate roll, 3, 4, and 5 are backup rolls, and 13 is a plate material. In addition, a is a taper cutting start end,
EL is the distance from the plate edge to the taper cutting start edge, L is the axial length of the taper, H is the amount of taper per radius, taper per diameter is 2H / L, 10 is a shape detector, 11
Is a shape calculation controller.

The rolls of the 12-high cluster mill are shown in FIG.
As shown in FIG. 2, a pair of upper and lower work rolls 1, 1, two pairs of upper and lower intermediate rolls 2, 2, a pair of upper and lower small backup rolls 3, 3, an upper pair of upper backup rolls 4, It consists of two pairs of lower backup rolls 5 on the lower side. In addition, the upper backup roll 4 is divided into seven parts, and the center, quarter,
They are called quarter-out and edge, respectively, and the upper backup roll crown can be adjusted by extruding while maintaining the left-right symmetry with respect to the center of the rolling mill. The lower backup roll 5 is divided into six parts, which are called center, quarter and edge from the center, respectively. The lower backup roll crown can be adjusted by extruding while maintaining left-right symmetry with respect to the center of the rolling mill. Have been. The upper and lower work rolls 1 and 1 can each be shifted in the axial direction by a shift cylinder via a thrust bearing (not shown).

In the cold rolling method of the present invention, as shown in FIG. 3, one end of each of the upper and lower work rolls 1 and 1 is tapered so as to be tapered, and the upper and lower work rolls 1 are rolled before the plate 13 is rolled. , 1 is moved in the axial direction, and the tapered tapered portions 1T, 1B are inserted into the plate material 13 from the plate edge to a predetermined range to set the shift position of the upper and lower work rolls 1, 1.

If the starting end a of the taper cutting is set outside the plate edge of the plate material 13, a composite elongation as shown in FIG. 8 occurs. The upper and lower work rolls 1 and 1 are moved to be inside the edge. Upper and lower work rolls 1 during rolling
1 is moved against the frictional force between the plate 13 and the work rolls 1, 1 and the frictional force between the upper and lower work rolls 1, 1 and the upper and lower intermediate rolls 2, 2. Therefore, the moving speed of the upper and lower work rolls 1 and 1 is slow,
It takes time until the composite elongation is improved, and the defective shape portion becomes longer.

Before the plate material B is rolled, the tapered starting ends a of the tapered portions 1T and 1B of the upper and lower work rolls 1 and 1 shown in FIG. By setting the shift position so as to be the distance, the composite elongation at the tip of the coil can be eliminated. Next, after rolling the plate 13, as shown in FIG. 4, the shape of the plate 13 is detected by the shape detector 10, and a deviation between the shape detected by the shape detector 10 and a target shape is calculated. The calculation is performed by the controller 11. Then, in accordance with the deviation calculated by the shape calculation controller 11, the upper backup roll is extruded and / or the intermediate roll bender is operated to control the shape so as to become the target shape.

Extrusion of upper backup roll and / or
Alternatively, since the intermediate roll bender has a high operating speed, even if there is a deviation between the shape detected by the shape detector 10 and the target shape, the shape can be corrected in a short time. The shape of the coil can be improved.
The shape calculation controller 11 also moves the upper and lower work rolls 1 and 1 in the axial direction to set shift positions of the upper and lower work rolls 1 and 1.

Further, in the cold rolling method in the cluster type rolling mill according to the present invention, the diameter of the upper and lower work rolls is set to 15
0 mm or less, and the taper 2H / L per diameter of the tapered portions 1T and 1B in the upper and lower work rolls shown in FIG.
1/700, and the tapered portion 1T, 1B from the plate edge of the plate material 13.
The distance EL to the beginning of the taper cut of 100 mm or more and 350 m
m or less.

The reason why the diameter of the upper and lower work rolls is set to 40 mm to 150 mm is that if the diameter of the work rolls exceeds 150 mm, the rolling load becomes excessively large and the defective shape easily occurs. On the other hand, if the diameter of the work roll is less than 40 mm, the work roll will bend in the horizontal direction, resulting in an unstable rolling state. Therefore, the diameter of the upper and lower work rolls is 40 mm to 150 mm
It is preferred that

The relationship between the sheet shape and the metal flow behavior in the sheet width direction of the sheet material was as follows when various rollings were performed. The effect of the tapered work roll is insufficient,
When an edge drop occurs in the rolled material, the material corresponding to the reduced sheet thickness becomes a metal flow in the sheet width direction. Also,
Even when the edge drop is reduced by the tapered work roll, the material having the increased thickness is generated by the metal flow in the width direction. The metal flow in the plate width direction to increase or decrease the thickness of these plate ends is 100 mm from the plate edge.
It occurs within the range up to. Also, from the plate edge to the plate edge
Changing the taper by placing the end a at the beginning of the taper cutting within a range of up to 100 mm has almost no effect on the composite elongation.

On the other hand, when the distance EL from the plate end to the taper cutting start end a shown in FIG. 3 exceeds 350 mm, the elongation at the center of the plate width becomes too large at the taper amount of 1/700. It is not preferable because it causes belly elongation. Therefore, the distance EL from the plate end shown in FIG. 3 to the end a of the tapered portion 1T, 1B at the beginning of the taper cutting is preferably 100 mm or more and 350 mm or less.

Further, as shown in FIG. 5, the relationship between the taper 2H / L per diameter and the plate shape is as follows. When the taper amount exceeds 1/700, the steepness exceeds 1%, and the frequency of occurrence of drawing and passing troubles decreases. Get higher. On the other hand, when the taper is less than 1/2500, the profile of the work roll that has become loose in the high order cannot be compensated, and the effect of suppressing the composite elongation becomes insufficient. Therefore, the taper 2H / L per diameter of the tapered portions 1T and 1B shown in FIG. 3 is preferably set to 1/2500 to 1/700.

As described above, the diameter of the upper and lower work rolls is 150 mm or less, and the taper per diameter is 1/2500 to 1 /
700 and the distance from the end of the plate to the start of taper cutting is 100 mm or more and 350 mm or less inside the width of the plate, so that composite elongation can be eliminated even for hard rolled materials such as SUS304 and SUS430. It is. In the cold rolling method in the cluster type rolling mill of the present invention described above, the shape of the plate 13 is detected by the shape detector 10, but in the cold rolling method of the present invention, the shape is detected by the shape detector 10. It is not limited to this. In the cold rolling method of the present invention, the split backup roll may be extruded and / or the intermediate roll bender may be operated based on visual judgment.

Although a 12-high rolling mill is used as the cluster rolling mill used in the present invention described above, the cluster rolling mill used in the cold rolling method of the present invention is not limited to 12 high rolling mills. In the present invention, any cluster-type rolling mill may be used. For example, a 20-stage cluster-type rolling mill may be used.

[0022]

EXAMPLE In a 12-stage cluster type rolling mill shown in FIGS. 1 and 2, a stainless steel coil (SUS304) having a sheet width of 1200 mm and a sheet thickness of 1.2 mm was cold-rolled to 20 coils and 0.9 mm. In addition, in the invention example, the upper and lower work roll diameters shown in FIG.
mm, taper 2H / L of upper and lower taper parts 1T, 1B 1/1000
The upper and lower work rolls were moved to set the distance EL from the plate edge to the taper cutting start edge before rolling to 160 mm. During rolling, as shown in FIG. 4, the shape of the plate 13 is detected by the shape detector 10, and the deviation between the shape detected by the shape detector 10 and the target shape is calculated by the shape calculation controller 11, Then, according to the deviation calculated by the shape calculation controller 11, the upper backup roll was pushed out and / or the intermediate roll bender was operated to control the shape so as to become the target shape. Rolling load is 7350kN, inlet and outlet tension is 274MP each
a and 314 MPa.

On the other hand, as a conventional example, a work roll without a taper is incorporated in the same 12-stage cluster type rolling mill as that of the invention, and the upper and lower work rolls are not moved. Was given. FIG. 6 is a graph showing one example of the plate shape in the above invention example in comparison with the conventional example.

From the results shown in FIG. 6, it can be seen that in the example of the invention, the composite elongation can be eliminated, the steepness of the plate shape is as good as 0.5%, and the shape of the plate material is remarkably improved. On the other hand, in the conventional example, the plate shape is a composite elongation, and the steepness of the plate shape is about 1.8
%, Rolling was extremely unstable, in which squeezing easily occurred. FIG. 7 is a graph comparing the number of coils at each steepness level of a rolled sheet in the invention example with that of the conventional example.

From the results shown in FIG. 7, in the invention example, compared to the conventional example, the plate shape was improved from the tip end of the coil and the steepness was reduced over the entire length, so that a coil having a good plate shape was obtained. You can see that there is.

[0026]

According to the cold rolling method of the present invention, the plate shape of the composite elongation can be eliminated and a good plate shape can be obtained from the tip of the coil to the entire length of the coil.
There is an excellent effect that productivity such as troubles such as drawing and breakage are eliminated and productivity is improved.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a roll layout of a cluster type rolling mill used in the present invention.

FIG. 2 is a side view of the cluster type rolling mill shown in FIG.

FIG. 3 is a schematic view showing a shape of a work roll used in the present invention.

FIG. 4 is a shape control block diagram of a cluster type rolling mill used in the present invention.

FIG. 5 is a graph showing the relationship between the work roll taper 2H / L and the steepness.

FIG. 6 is a graph comparing the plate shape in the invention example with the conventional method.

FIG. 7 is a graph comparing the number of coils at each steepness level of a rolled sheet in the invention example with the conventional method.

FIG. 8 is a graph showing a conventional plate shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work roll 1T, 1B Tapered part 2 Intermediate roll 3 Small backup roll 4 Upper backup roll 5 Lower backup roll 13 Plate material a Start of taper cutting L Length of taper in the axial direction H Tapered amount per radius EL Start of taper cutting from plate end Distance to 10 Shape detector 11 Shape calculation controller

Continued on the front page (72) Inventor Shigefumi Katsura 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside Kawasaki Steel Works, Ltd. F term in Chiba Works (Reference) 4E024 AA01 DD05 DD10 DD18 EE05

Claims (2)

[Claims] 1. An upper and lower work roll is provided with a tapered taper on one end thereof, incorporated into a rolling mill so that the taper is vertically opposite to each other, and the upper and lower work rolls are moved in the axial direction to form a shape. In the cold rolling method of the plate material in a cluster type rolling mill that performs rolling on the plate material while controlling the position, before rolling the plate material in the rolling mill, the position of the tapered start end is inward from the plate edge of the plate material. The shift position is set by moving the upper and lower work rolls so as to be a predetermined distance, and after rolling the plate material by the rolling mill,
A method for cold rolling a plate material in a cluster type rolling mill, wherein the backup roll is extruded and / or an intermediate roll bender is operated in accordance with a change in the shape of the plate material of the rolling mill so as to have a target shape. 2. The method according to claim 1, wherein the diameter of the upper and lower work rolls is 150 mm or less, the taper is 1/2500 to 1/700, and the distance from the plate edge of the plate to the taper cutting start end is 10 mm.
2. The method for cold rolling a sheet material in a cluster type rolling mill according to claim 1, wherein the thickness is 0 mm or more and 350 mm or less.