JPS63199003A - Rolling method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a rolling method using a four-high rolling mill in which reinforcing rolls can be shifted in the axial direction, and particularly a rolling method that is excellent in edge drop control ability of rolled material and The present invention relates to a rolling method that can improve the life of reinforcing rolls.

<Conventional technology> FIG. 8 shows an example of a four-high rolling mill.

The four-high rolling mill has work rolls 2. which directly roll the rolled material 3.
2 and a reinforcing roll 1.1 pressed against the work roll.

When rolling is performed using such a four-high rolling mill, as shown in the four-high rolling mill shown in FIG. In FIG. 10, a plate crown represented by H3-Hl and an edge drop represented by H2-H are produced.

In particular, take a one-pass reduction rate of 70% or more, - strongly reduce the pressure,
In clad rolling, where composite metal strips are produced by deformation and pressure welding, extreme edge drop causes end cracks and edge elongation, causing waves in the rolled material, making it impossible to obtain rolled material with good tightness. .

In order to improve such plate crowns and edge drops, a rolling method using a four-high rolling mill equipped with reinforcing rolls that have tapered portions 12 at both ends and can be shifted in the axial direction as shown in Fig. 11 has been proposed. is being tested.

By rolling the reinforcing roll 1.1 having such a taper in a shifted four-high rolling mill, the work roll 2.1 is rolled.
2 is given a deflection deformation along the tapered portion 12 of the reinforcing rolls 1, 1, and the work rolls 2.
2 to reduce the plate crown and edge drop of the rolled material 3.

However, this type of rolling method has the following problems.

(1) When the reinforcing roll 1.1 and the work roll 2.2 are made of forged steel, especially in rolling with a large rolling reduction such as clad rolling, the reinforcing roll 1.1 and the work roll 2, 2 are made of forged steel.
The amount of oblate deformation increases.

Therefore, the work roll 2 near the widthwise end of the rolled material 3.
The gap between the work rolls 2 narrows, the plate crown and edge drop increase, the effect of deflection deformation along the tapered part 12 of the work roll 2 weakens, and the effect of shifting the tapered reinforcing roll in the axial direction almost disappears. .

(2) If the reinforcing roll 1.1 and the work roll 2.2 are made of the same material, the burn-in, scratches, or unevenness caused by wear on the work roll 2.2 will be directly transferred to the reinforcing rolls 1, 1. The circumferential surface of 1 is rough, reinforcing roll 1.1
lifespan becomes shorter.

(3) When the tapered portions 12 of the reinforcing rolls 1, 1 are shifted to the center of the rolled material 3, the work roll 2 is deflected in an inverted V shape, and due to subtle changes in rolling conditions, the rolled material 3 escapes in the roll axis direction. Not suitable for stable rolling operations.

(4) A device for applying a pending force to the work roll 2 or the reinforcing roll 1, for example, using a reinforcing roll bender or a work roll bender, a pending force 15 to be applied to the work roll shown in FIG. 11, a pending force to be applied to the reinforcing roll. 5 is effective in adjusting the shape and reducing edge drop, but is not suitable for eliminating the extreme edge drop that occurs when rolling under heavy pressure.

As described above, with the conventional rolling method using a combination of rolling rolls, it is difficult to manufacture a composite metal strip in a sound manner and obtain a sheet shape.

<Problems to be Solved by the Invention> An object of the present invention is to provide a rolling method that eliminates the drawbacks of the prior art described above, has excellent edge drop control ability of rolled material, and can improve the life of the rolls. It is in.

〈Means for solving problems〉 Such objects are achieved by the present invention as described below.

That is, in the present invention, rolling is performed using a four-high rolling mill that is composed of a pair of work rolls that directly roll the rolled material, and a pair of reinforcing rolls that apply rolling force to the work rolls and are shiftable in the axial direction. In this case, each reinforcing roll is composed of a substantially cylindrical cylindrical part and a tapered part at one or both ends of the cylindrical part, and has a longitudinal elastic modulus E at a predetermined thickness from the outer peripheral surface over the entire circumference of the cylindrical part in the circumferential direction. is 30000gf/a+
m2 or more, and has a high longitudinal elastic modulus portion whose axial length is a predetermined length shorter than the width of the rolled material, the end of the high longitudinal elastic modulus portion of the one reinforcing roll is connected to the rolled material. Approximately 1/1/1 of the predetermined length from one widthwise end of the
This rolling method is characterized by rolling by shifting a pair of reinforcing rolls so that they are located 2 to 1 points inside.

Here, it is preferable to use a rolling method in which the high longitudinal elastic modulus portion is formed into a sleeve shape.

Further, the predetermined length is approximately twice the length corresponding to a portion where an edge drop occurs at one end of the rolled material, or a length corresponding to a portion where an edge drop occurs at both ends of the rolled material. Preferably, the rolling method is

EMBODIMENT OF THE INVENTION Hereinafter, the rolling method of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

An example of the configuration of a four-high rolling mill used in the method of the present invention is shown in FIG.

The reinforcing roll 1 used in the method of the present invention mainly consists of a cylindrical part that contributes to rolling of the rolled material and a tapered part at one end or both ends of the cylindrical part (hereinafter referred to as the reinforcing roll tapered part 12). A predetermined thickness from the outer circumferential surface over the entire circumferential direction.

It has a high longitudinal elastic modulus portion 13 whose longitudinal elastic modulus E is 30,000 gf/rnm2 or more and whose axial length is shorter than the width of the rolled material 3 by a predetermined length (22) shown in FIG. It is something.

Note that the taper angle of the reinforcing roll tapered portion 12 (0 in FIG.
1) is preferably about 1 to 1.5 degrees.

This high longitudinal elastic modulus portion 13 has a longitudinal elastic modulus E of 30,000.
material with gf/mm2 or more, e.g. 35000 kg
f/mm2 tungsten (w), molybdenum: / (M
o), 40000Kgf/mm2 (D7) Ii mina (81□0.92-94%, 5in2, MgO remainder, etc.), WC
-Co sintered alloy, titanium nitride (TiN), silicon nitride (Si3N), etc.

In addition, titanium nitride (
It is also good to use a material whose surface has been treated to have a thickness of 3 to 5 μm.

The cylindrical part 1 and the reinforcing roll tapered part 12 are made of a material with a longitudinal elastic modulus E smaller than the material L, such as forged steel, Fc-N.
It is made of i-alloy, Fe-based alloy, copper, copper alloy, etc.

Note that the longitudinal elastic modulus E of the high longitudinal elastic modulus portion 13 is 30,000.
If it is smaller than Kgf/mm2, the effect of reducing plate crown and edge drop will be insufficient, as shown in the examples below.

In the following explanation, the reinforcing roll above the rolled material 3 of the illustrated four-high rolling mill! and work roll 2,! The reinforcing roll 1 and work roll 2 below the rolling material 3 are the reinforcing roll 1 and work roll 2 on the other side.

Further, when facing the figure, the left direction position is the left side, and the right direction position is the right side.

A pair of reinforcing rolls 1 and t of such a four-high rolling machine are
As shown in the figure, the high longitudinal elastic modulus part 1 of one reinforcing roll l
3 is located a predetermined length inside the left end A in the width direction of the rolled material 3 (indicated by 01 in FIG. 1), and the end of the high longitudinal elastic modulus portion 13 of the other reinforcing roll 1 is rolled material 3
1 in FIG. Shift to the inside position (indicated by ) and perform rolling.

In the method of the present invention, the edge drop is reduced due to the synergistic effect of the reinforcing roll tapered part 12 and the high longitudinal elastic modulus part 13, which is shorter than the rolled material 3 by a predetermined length. The position of the high longitudinal elastic modulus portion 13 of the reinforcing roll l on the left and right sides is the same length! , it is not limited to the case where it is located on the inside of the wall, but it is also possible to roll it asymmetrically in the range of 11 to 211 (that is, on the inside by about 1/2 to 1 of the predetermined length). Even in this case, the positional relationship between the upper and lower reinforcing rolls 1.1 of the rolled material 3 is symmetrical with respect to the center point of the rolled material 3.

That is, the axial length of the high longitudinal elastic modulus portion 13 is set to be a predetermined length, approximately 21°, shorter than the widthwise length of the rolled material.
Here 1. The length of is determined according to the shape of the rolled material to be rolled, and it is thought that an edge drop will always occur at about 10 to 30% of the width of the rolled material 3 or at one end of the rolled material 3. It is preferable that the length corresponds to the length of the part.

Here, in the method of the present invention, the edge drop can be reduced due to the synergistic effect of the reinforcing roll tapered part 12 and the high longitudinal elastic modulus part 13, which is shorter than the rolled material 3 by a predetermined length.
1. can be selected not only to the above-mentioned optimum length but also to a wide range.

Note that the reinforcing roll tapered portion 12 is not necessarily the same as the columnar portion 11.
It does not have to be formed on both ends of the 0 side, and may be formed only on the side involved in edge drop reduction. The same applies to other configuration examples described later.

When rolling is performed using such a four-high rolling mill, the edge drop at the left end A of the rolled material 3 is first reduced as described below.

The reinforcing roll 1 has a high longitudinal elastic modulus part 1 on the outer periphery of the columnar part 11.
3, a side surface made of a material with a smaller longitudinal elastic modulus than the high longitudinal elastic modulus part 13 of the cylindrical part 11, and a reinforcing roll tapered part 12 made of a material with a smaller longitudinal elastic modulus as well. As shown in an exaggerated manner, the high longitudinal elastic modulus portion 13 hardly undergoes flattening deformation, and the flattening deformation of the reinforcing roll tapered portion 12 is relatively large. The flattening of the reinforcing roll 1 at this time is shown, for example, in FIG. 2 as a change from a two-dot chain line located above one end A of the rolled material to a solid line. Therefore, the deflection deformation of the work roll 2 along the reinforcement roll tapered portion 12 due to the shift of the reinforcement roll 1 becomes large, and the gap between the work rolls 2.2 near the widthwise ends of the rolled material 3 widens. Therefore, the plate crown and edge drop of the rolled material 3 are reduced.

In addition, at the right end E of the rolled material 3, the high longitudinal elasticity member 13 has a length up to C, and the surface of the reinforcing roll 10 in contact with the work roll 2 is the distance from C onwards to the right end E of the rolled material. Target I
, the amount of flattening deformation of the reinforcing roll 1 near the position where a perpendicular line extending from E intersects with the side surface of the reinforcing roll is Negative direction (direction where the roll gap becomes larger)
The taper angle becomes larger, and a similar force is applied to the work roll 2. Therefore, the edge drop at the right end E of the rolled material 3 is reduced, resulting in a good sheet crown. becomes.

FIG. 3 shows another example of the structure of the reinforcing roll of the four-high rolling mill used in the method of the present invention. The positional relationship between this reinforcing roll and the rolled material during rolling is the same as that of the four-high rolling mill shown in FIG. 1. The same applies to FIGS. 4 to 6 described below.

The reinforcing roll 1 shown in FIG. 3 has a high longitudinal elastic modulus portion 13 formed so as to form a crown toward the center of the roll body of the reinforcing roll 1.

In FIG. 3, h is the thickness near the center of the high longitudinal elastic modulus section 13, and h2 is the thickness at the end of the high longitudinal elastic modulus section 13. Further, ff12 is the width of the tapered portion of the high longitudinal elastic modulus portion 13. Note that this tapered portion does not need to be formed at both ends of the high modulus of longitudinal elasticity portion 13, and may be formed only on the side involved in reducing the edge drop of the rolled material 3. Moreover, h2=0 may be sufficient.

The high modulus of longitudinal elasticity part 13 is reinforced with the tapered part 1 of the roll in this way.
2, the change in rigidity from the cylindrical portion 11 to the reinforcing roll tapered portion 12 becomes smooth, and edge drop is improved more smoothly.

In addition, in order to obtain the above effects, it is not necessary to use a third
The reinforcing roll 1 is not limited to the structure shown in the figure, but any structure in which the thickness of the high longitudinal elastic modulus part 13 gradually decreases toward the side end of the cylindrical part 11 as shown in Fig. 4 can be used. A reinforcing roll having a high longitudinal elastic modulus portion with a cross-sectional shape may also be used.

Even in such a case, the cross-sectional shape of the high longitudinal elastic modulus portion does not need to be bilaterally symmetrical, and it is sufficient that the thickness of the high longitudinal elastic modulus portion gradually decreases at least toward the side that participates in edge drop reduction.

Furthermore, such a high longitudinal elastic modulus portion 13 whose thickness gradually decreases is not limited to the outer periphery of the columnar portion 11, but may be formed by extending to the outer periphery of the tapered portion on the left side of the reinforcing roll, as shown in FIG. . Even in this case, the axial length and positional relationship of the high longitudinal elastic modulus portion 13 are as described above.

By using a reinforcing roll having such a high longitudinal elastic modulus portion, edge drops can be smoothly reduced.

In each of the above configuration examples, when the high longitudinal elastic modulus section 13 is formed into a sleeve shape, the high longitudinal elastic modulus section 13 is mechanically combined with the cylindrical section 11, and silver soldering is performed after this combination. Alternatively, they may be joined by an appropriate method such as casting, mechanical assembly (screwing), press-fitting, or sintering.

<Example> Hereinafter, the present invention will be described in more detail by giving examples of the present invention.

(Example 1 and Comparative Example) In the four-high rolling mill shown in FIG.
0 mm, tapered (taper angle 1.5 degrees), reinforcing roll 1 diameter φ400 mm, width of each reinforcing roll tapered part 12 40 mm, taper angle θ1 of reinforcing roll tapered part 1 degree,
In a four-high rolling mill with a cylindrical part 11 having a width of 120 mm and a shiftable reinforcing roll, a Fe-42%Ni alloy strip having a thickness of 1.5 mm and a width of 100 mm was rolled in one bath to a thickness of 0.45 mm. The work roll 2 material is made of forged steel (longitudinal elastic modulus E = 21000 kgf/mm2), and only half of the roll length of the parallel part of the tapered reinforcing roll of the forged steel roll (that is, 20 mo+ from the rolled material width of 100 mm) is used.
Short 80rRrn) Longitudinal elastic modulus is 64000 kgf/
A roll made of a mm2 cemented carbide (WC-Co sintered) alloy with a thickness of 20 mm was manufactured and rolled.

On the other hand, when a conventional forged steel tapered reinforcing roll (taper angle 1.5 degrees) is shifted inward by jL = 10 mm from the edge of the rolled material, the plate crown is 12/100+nm and the edge drop is 7/1100a. Waves also occurred in the longitudinal direction of the board.

When using the above four-high rolling mill and performing the same shift as in the conventional example using the method of the present invention, the plate crown of the plate is 6/100 mm,
The edge drop was reduced to 3/100, and the plate shape was also good. In addition, stable rolling work was possible without the rolled material escaping in the axial direction due to shifts under heavy rolling.

(Example 2) In a 4-high rolling mill having the same mechanism as in Example 1, the tapered reinforcing roll was changed to a longitudinal elastic modulus of only half (80 mm) of the roll length of the parallel part of the forged steel roll shown in Fig. 4 (160 mtn). is 64000 kgf/mm2.
Made of sintered alloy, 20III thick at the thickest point
A roll having an I++ tapered shape formed by press-fitting was manufactured and installed in the above-mentioned four-high rolling mill.

Furthermore, Fe-42%Ni alloy strip thickness 1.5mm, width 10
Roll 0mm to 0.45mm in one pass using a tapered reinforcing roll (taper angle 1.5 degrees) from the edge of the rolled material in the same positional relationship as shown in Figure 6. ,=10 mm shifted inward, and the plate crown and plate shape were measured.

The plate crown was reduced to 5/100mII+, and the edge drop was reduced to 3/100mm. Moreover, when observing the thickness in the width direction of the strip from a cross section, as shown in FIG. The thickness change was smooth, and the plate shape was good with no waves or the like.

In addition, seizures, scratches, or unevenness due to wear on the work roll are reduced in the edge drop region, and as a result, the life of the roll replacement due to roughening of the reinforcing roll surface due to transfer of the surface of the work roll is extended.

<Effects of the Invention> (1) By using the method of the present invention, the deflection deformation effect of the work roll in the tapered portion can be effectively exhibited, and the flattening deformation of the roll can also be effectively utilized by forming a member with a high elastic modulus.
Even when rolling under heavy reduction and high pressure load, plate crown is reduced, and in particular, edge drop can be reduced.

(2) In rolling under strong reduction (60% working or higher), edge drops can be reduced, edge cracks and waves due to edge elongation can be prevented, and a rolled material with good shape (flatness) can be obtained.

(3) Even if the tapered part of the tapered reinforcing roll is shifted to the center of the plate of the rolled material, the rolled material will not escape in the roll axis direction and will remain stable even if the rolling conditions (speed, slip resistance, longitudinal tension) change. It is possible to carry out rolling work.

(4) Furthermore, since the edge drop area is improved, local increases in blood pressure are reduced, seizures on the roll surface are also reduced, and the life of the roll is improved.

(5) By replacing the reinforcing rolls of a 4-high rolling mill with a roll shift mechanism without requiring a large roll pentameter in the rolling mill, edge drop and plate crown can be improved, allowing industrial high-reduction rolling. This is an effective edge drop reduction method.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the configuration of a four-high rolling mill used in the method of the present invention. FIG. 2 is a partially sectional view showing an exaggerated state in which the method of the present invention is implemented. FIGS. 3, 4, and 5 are cross-sectional views showing various configuration examples of reinforcing rolls of a four-high rolling mill used in the method of the present invention. FIG. 6 is an explanatory diagram showing the dimensions of the four-high rolling mill used in Example 1. FIG. 7 is an explanatory diagram of a cross-sectional plate thickness distribution profile of a rolled material showing the results of implementing the method of the present invention. FIG. 8 is a schematic front view for explaining a general four-high rolling mill. FIG. 9 is a front view showing the rolling state when the general four-high rolling mill shown in FIG. 8 is used. FIG. 10 is a cross-sectional view of a rolled material for explaining plate crowns and edge drops. FIG. 11 is a schematic front view for explaining the four-high rolling mill with the reinforcing rolls shifted. Explanation of symbols 1... Reinforcement roll, 2... Work roll, 3... Rolled material, 5... Bending force used in the reinforcement roll, 6...
...Left end of cylinder part, 11--Cylindrical part, 12--Reinforcement roll tapered part, 13--High longitudinal elastic modulus part, 15-Pending force applied to work roll, 16--Cylindrical part. Right end of the section, A... Left end, B - Left end of the high longitudinal elastic modulus section, C... Right end of the high longitudinal elastic modulus section, D... Position, E... - Right side end H, -... Thickness of the rolled material plate end, H2... Thickness at a point 5 mm into the center from the rolled material plate edge,

Claims (3)

[Claims] (1) When rolling a material using a four-high rolling mill consisting of a pair of work rolls that directly roll the material and a pair of reinforcing rolls that apply rolling force to the work rolls and are shiftable in the axial direction, Each reinforcing roll is composed of a substantially cylindrical cylindrical part and a tapered part at one or both ends of the cylindrical part, and has a longitudinal elastic modulus E of 30,000 Kgf/ mm^2 or more and having a high longitudinal elastic modulus portion whose axial length is a predetermined length shorter than the width of the rolled material, the end of the high longitudinal elastic modulus portion of the one reinforcing roll is Approximately 1/1/2 of the predetermined length from one widthwise end of the rolled material
A rolling method comprising shifting the pair of reinforcing rolls so that they are located 2 to 1 points inside. (2) The rolling method according to claim 1, wherein the high longitudinal elastic modulus portion is formed in a sleeve shape. (3) The predetermined length is approximately twice the length corresponding to the portion where an edge drop occurs at one end of the rolled material, or corresponds to the portion where an edge drop occurs at both ends of the rolled material. The rolling method according to claim 1 or 2, which is a length.