JPH01202301A - Method for rolling flat stock - Google Patents

Abstract

PURPOSE:To prevent convexity caused by bulging of edge faces and to improve the yield by rolling the edge faces to be a recessed shape in hot rolling of a flat stock. CONSTITUTION:A rolled stock 1 is rolled in the edge direction by grooved rolls 2 and edge faces are formed into a recessed shape, and then the stock 1 is rolled in the flat face direction in the final stage. In that time, the edge faces are restrained to be a convex shape and corners are made to be sharp because the edge faces are the recessed shape. Another light rolling in the edge direction is performable after rolling in the flat face direction in the final stage. Thus, flatness caused by bulging of the edge face is improved, a machining time is reduced, and the yield is improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for rolling a flat material by hot rolling.

[Conventional technology]

In hot rolling of a flat material, the material to be rolled is generally repeatedly rolled alternately from directions perpendicular to each other. That is, for a flat material, rolling is performed alternately from the edge (referred to as "edge" in the present invention) surface direction using grooved rolls and from the flat surface (front and back surface) direction using flat rolls. The reason why grooved rolls are used here is to prevent the rolled material from falling over.

In these rolling processes, the traverse portions (referred to as corners in the present invention) of the rolled material are easily susceptible to dents, and in some cases are prone to cracking. Therefore, as much as possible during the long rolling process, large corners are The radius is maintained and the necessary sharp corner shape is achieved in the final stage.

Products produced by these rolling methods are shown in Figure 2 A and B.
As shown in , the ridged surface bulges out in an arc shape with radius R1 at the center in the thickness direction, and some corners are relatively sharp (A), or are chamfered with dimension C (B). There are many.

[Problem to be solved by the invention]

When cutting a part with sharp edges from a rolled flat material as described above, even with a sharp cross-sectional shape as shown in (A) above, an excessive cutting allowance is required, and black scale remains on some corners. Such inconveniences may occur. Therefore, in this case, the material needs to be sharp edged, and the center and height of the ridged surface should be eliminated.

An object of the present invention is to provide a method for rolling flat and square materials that reduces the bulging of the rough surface of the product and efficiently creates sharp edges with a small number of rolling passes.

[Means to solve the problem]

The present invention is a flat material rolling method in which the flat material is repeatedly rolled in directions perpendicular to each other, and is characterized by a process of forming a cross-sectional shape in which the ribbed surface is concave.

[Effect]

In the present invention, since the material to be rolled is rolled from the direction of the heel surface after the edge surface has been made concave in advance, the effect of increasing the center height due to rolling from the direction of the hem surface can be offset.

It is desirable that the present invention be carried out at the final stage of the rolling process to prevent damage during the formation of sharp corners or after the formation of bumps.

〔Example〕

Next, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows the roll hole shape of the immediately preceding finishing roll in which the present invention is implemented. It consists of a side surface 4.4 that opens out in the same way as the mold.

The material to be rolled 1 is rolled from the direction of the heel through this groove, and after the knurled surface is made concave, it is rolled from the direction of the heel in the final stage. At this time, the koba side is.

Since it has a concave shape in advance, it is suppressed from becoming medium-height.

In hot rolling of a flat material with product dimensions of 4.5m x 20.3cm, a flat material with an arcuate bulge on the edge surface was rolled with the above-mentioned finishing corrugating rolls, and then rolled with a flat finishing final roll. , the bulge on the rough surface of the product.

Conventionally, it was about 0.6 mm, but this was reduced to 0.2 mm or less, and the corner edge was made even sharper.

〔Effect of the invention〕

As described above, according to the present invention, the lack of flatness caused by the bulging of the ridged surface of conventional flat materials can be significantly improved, the machining time for machining products, etc. can be reduced, and the machining yield can be improved. becomes possible.

The present invention is applicable not only to the method in which the concave surface is processed into a concave shape immediately before the final stage rolling, and then rolled from the flat surface direction in the final stage, as in the above embodiment, but also to It is also possible to make a small reduction from the direction of the palm.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a roll hole type according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of the shape of a part of a corner of a flat material. 1゛: Rolled material, 2: Roll hole shape, R: Radius, 3: Groove bottom, 4: Side surface

Claims (1)

[Claims] 1. A method for hot rolling a flat material in which flat material is repeatedly rolled in directions perpendicular to each other, the method comprising the step of forming a cross-sectional shape in which the ribbed surface is concave.