JPS623802A - Rolling method for extra-thin sheet - Google Patents

Abstract

PURPOSE:To prevent the camber and longitudinal wrinkle of a rolling material by exerting bending tension to the rolling material then coiling the rolling material by a reel having a recessed crown. CONSTITUTION:The rolling material 4 is let off from a supply reel 5, wraps around a large-diameter roll 1, passes the spacing between the roll 1 and a roll 3 then through the roll 3 and a roll 2 and emerges from a CBS rolling mill 10. The material passes a leveler 7 and is finally taken up on the reel 6. The leveler 7 is installed with bending rolls arranged zigzag and the recessed crown reel is used for the reel 6. The material is taken up on the reel 6 after the camber is leveled by the camber leveler 7, by which the camber and longitudinal wrinkle of the extra-thin hard rolling material are prevented.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a method for rolling ultra-thin hard materials.

(b) Conventional technology Rolling of ultra-thin hard materials has traditionally been extremely difficult.

Generally, the minimum rollable thickness tmin of a copper strip is as follows (1
) O tmincQD, U, (k-τ)/E ・----
-(1) Here, D: Roll diameter U: Friction coefficient: Deformation resistance T: Average tension E: Roll Young's modulus (1) As is clear from equation (1), when trying to roll a material with high deformation resistance thinly Therefore, it is necessary to reduce the roll diameter. If the roll diameter is made smaller, roll horizontal deflection becomes a problem and an expensive multi-stage mill such as the Sendzimir fist mill is required. However, it is difficult to achieve good flatness for thin and wide materials, and 5US304 material
．． 25 to 0.3 is the minimum board thickness for manufacturing. but,
Recently, there has been a growing demand for thinner copper strips, and the development of a compact rolling method is desired.

Around 1960, GE developed the CBS rolling method (Contact Bend 5tret) as shown in Figure 6.
ch) has been considered, but it has not been put into practical use. This is done by inserting a small-diameter floating roll 6 between the large-diameter rolls 1 and 2 and rolling at different speeds (roll 1 is at a low speed V, roll 2 is at a high speed V).
This is a method of performing H). Its characteristics are that the influence of rolling and longitudinal tension fluctuations is very small, and the deflection of the small-diameter floating roll B is supported by the large-diameter rolls 1 and 2, and the small-diameter floating roll B has a self-control effect on the shape of the rolled material 4. This is because it enables rolling with a good shape.

Recently, it was discovered at the Spring Lecture on Plastic Working in 1981 that stable rolling is possible without particularly wrapping the rolling material 4 around the large diameter roll 2 on the exit side as shown in Figure 6(B). It has been announced (pages 77-80 of the lecture proceedings).

Although the CBS rolling method has many features for rolling ultra-thin hard materials, since the rolled material 4 is wound around the floating small diameter roll 3 and rolled, warpage defects occur in the rolled material. This is an unavoidable drawback of the rollability that is not observed in general rolling methods.

Board warpage is generally classified into longitudinal warpage and width direction warpage. In this rolling method, tension is applied to the rolled material in the longitudinal direction, so even if longitudinal warpage is a characteristic of the rolled material itself, it is erased by the tension during rolling, and the apparent upward warpage is detected as width warping. be done.

When width warpage occurs, it causes problems in measuring the plate thickness during rolling, and also has a negative effect on the occurrence of vertical wrinkles during roll winding, which is a particular problem with ultra-thin materials. Even if one rolling is successful, the problem arises that it cannot be rolled up and cannot be made into a finished product. Furthermore, even if the material is relatively thick and warped and no vertical wrinkles occur during winding, various problems such as poor welding and scratches with incidental equipment may occur in the next process.

C. Problems to be Solved by the Invention The problems to be solved by the present invention are that, in the CBS rolling method of ultra-thin materials, it is possible to prevent sheet warpage from occurring in the rolled material and to generate vertical wrinkles when the rolled material is wound up. It's about not letting it happen.

(→Means for Solving the Problems) In the method of rolling ultra-thin material of the present invention, a small-diameter floating roll is installed between a pair of large-diameter rolls that rotate in the same direction with a predetermined interval, and the small-diameter floating roll is A rolled material is inserted between the large diameter roll and the small diameter floating roll with their traveling directions opposite to each other so as to press the floating rolls against the large diameter roll, and the rolled material is rolled at different circumferential speeds between the rolls. The above problem is solved by applying bending tension to the rolled material after rolling.

The method of the present invention solves the above problems by applying bending tension to the rolled material and then winding the rolled material using a reel with a concave crown.

(E) Function In the method of the present invention, the warpage of the rolled material is eliminated by applying bending tension to the rolled material after rolling, and the rolled material is wound up using a roll with a concave round when winding the rolled material. This prevents the occurrence of vertical wrinkles in the rolled material.

(f) Example A CBS rolling mill to which the rolling method of the present invention is applied is shown in FIG. The conventional CBS rolling mill 10 has a small-diameter floating roll 6 installed between a pair of large-diameter rolls 1 and 2 that rotate in the same direction at a predetermined interval, and the roll 6 is connected to the rolls 1 and 2.
So that they can suppress each other, and support floating.

The rolled material 4 is fed out from the supply reel 5, passes through the gap between the rolls 1 and 3 with a large diameter of 0-1, and passes through the gap between the rolls 1 and 3.
Then, it passes through the gap between roll 3 and roll 2 on the left, and exits the CBS rolling mill 10. The roll 6 is pressed against the rolls 1 and 2 by the inter-reel tension of the rolled material 4.

According to the method of the present invention, a normal straightening machine 7 is provided on the exit side of the CBS rolling mill 10, and the rolled material 4 after CBS rolling is transferred to the straightening machine 7.
When the CBS rolling mill 10 performs reverse rolling, the second
As shown in the figure, a straightening machine 7 is installed on the entry and exit side of the CBS rolling mill 10.
can be provided.

The straightening machine 7 is equipped with bending rolls arranged in a staggered manner (usually a central small-diameter roll is moved up and down), and uses reel tension and bending tension caused by roll bending to straighten warpage that occurs after CBS rolling.

As shown in FIG. 1 or FIG. 6, the straightening machine 7 has six
In addition to the set configuration, multiple rolls as shown in FIGS. 4(G) and 4(B) may also be used. The greater the number of rolls, the more stable the straightening function will be.

In addition, in CBS rolling, even if the longitudinal tension is varied considerably, the rolling reduction rate is determined by the true speed ratio, so it differs from normal rolling in that not only roll reduction adjustment but also tension adjustment can be used for warp correction.

Furthermore, even with ultra-thin materials, especially when the thickness is less than 100μ and the width/thickness ratio is about 1.5X10 or more, as shown in Figure 5, vertical wrinkles occur frequently during winding, and the rolling process itself becomes more difficult. A problem occurs in the winding operation. When we tried to numerically solve this phenomenon, we found that the main cause is that the cross-sectional distribution of plate thickness is medium and high, and the winding tension at the center of the width is high, which induces compressive stress in the width direction. It turned out that I was born.

The conventional winding rule 6 was flat as shown in FIG. 6 (4), but as a countermeasure against the vertical wrinkles mentioned above, (B)
It was proposed to use a convex crown reel as shown in the figure.

However, the present inventors have confirmed that it is more effective to use a concave crown reel as shown in Figure (C).

Naturally, warping of the board has a negative effect on the generation of vertical wrinkles, so after straightening the warp of the board using a warping straightening machine, the board is wound onto this concave lounge reel for the first time in the production of wide and ultra-thin materials. becomes possible. Note that in order to be able to change the crown value depending on the material and plate width, it is desirable that the reel structure be a variable crown type reel.

(g) Specific example: A CB shown in Fig. 1, which has a large diameter roll of 250 fl, a small diameter roll of 30 mm, and a roll barrel of 460 m.
On the exit side of the S rolling mill 10, there are two 100 mm diameter and 20 m diameter
One straightening machine 7 was attached to the outlet housing. A steel vapor having a thickness of 50 μm and a width of 300 m++ was rolled entirely at a reduction rate (true speed rate) of 1 to 50%.

When the warpage correction roll is opened, only the width warpage is detected under tension on the exit side, and both are downwardly convex warps, and the amount of warpage changes depending on the rolling reduction rate and tension.

We also tried changing the angle of the exit pass line, but no major changes were observed.

Next, the rolling reduction ratio was kept constant at 40%, and the center small diameter roll of the straightening roll was moved up and down to examine changes in board warpage. It was found that when the pushing amount of the small-diameter roll was increased, the warp of the board changed from a downward convexity to an upward convexity, and that the warp of the board could be eliminated at an appropriate value.

When the plate thickness reached approximately 20 μm due to multi-pass rolling, wrinkles began to appear during winding.

At this time, if you straighten the warp, the distance between the roll and reel will be shortened, which will certainly make wrinkles less likely to occur, but wrinkles will quickly appear due to changes in line speed, etc. As a result, production was halted.

Therefore, when reel B was winded with a concave crown (20 μm/diameter), stable winding was possible without wrinkles even when the exit side plate thickness was 10 μm.

Next, the small-diameter floating roll 6 was replaced with one having a diameter of 10 mm, and an experiment was conducted in which a stainless steel material with a thickness of 50 μm was rolled to 10 μm in 6 passes. At this time, the width warpage is much larger than in the case described above, with 2 pieces of 100cm diameter and 1 piece of 20cm diameter.
Since it was not possible to correct the width warp with a book straightening roll,
The rolling reduction amount was adjusted by replacing the 20-day diameter roll in the center with a 12-meter diameter roll. As a result, the width warpage disappeared. In addition, when we fixed the rolling amount at a position where the width warpage was approximately O and varied the tension, we found that the warp was convex upward at high tension and convex downward at low tension, and that the warpage could be adjusted by adjusting the tension. confirmed. The experiment was conducted with the reel provided with a concave crown.

(Force Effect: According to the method of the present invention, by making slight improvements to existing equipment, it is possible to easily and reliably prevent plate warpage and vertical wrinkles in ultra-thin hard rolled materials, which were difficult to avoid with conventional methods. I can do it.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a rolling mill to which the rolling method of the present invention is applied. FIG. 2 is a drawing similar to FIG. 1 and shows a modified example. FIG. 6 is a plan view showing a take-up reel used in the method of the present invention and a take-up reel used in the conventional method. FIG. 4 is a schematic explanatory diagram of a straightening machine used in the method of the present invention. FIG. 5 is an explanatory diagram of vertical wrinkles that occur during winding of the steel strip. Figure 6 shows the conventional CB
A schematic explanatory diagram of the S rolling method.

Claims (2)

[Claims] (1) Rotating in the same direction with a predetermined interval 1
A small-diameter floating roll is installed between a pair of large-diameter rolls, and the rolled material is placed between the large-diameter roll and the small-diameter floating roll in opposite directions to each other so as to press the small-diameter floating roll against the large-diameter roll. 1. A method for rolling an ultra-thin material, comprising: inserting the material into the rolled material, applying different circumferential speed rolling to the rolled material between the rolls, and applying bending tension to the rolled material after rolling. (2) Rotating in the same direction with a predetermined interval 1
A small-diameter floating roll is installed between a pair of large-diameter rolls, and the rolled material is placed between the large-diameter roll and the small-diameter floating roll in opposite directions to each other so as to press the small-diameter floating roll against the large-diameter roll. The ultra-thin method is characterized in that the rolled material is inserted through the roll, the rolled material is rolled at different peripheral speeds between the rolls, bending tension is applied to the rolled material after rolling, and then the rolled material is wound up on a reel with a concave crown. Method of rolling material.