A kind of round steel slitting and rolling process

Abstract

The invention discloses a round steel cutting and rolling process. In this round steel split rolling process, after the round holes are rolled out in the rough and intermediate rolling stage, the roll passes used in the finish rolling stage are: flat rolling pass, vertical box pass, pre-splitting pass, Segmented, oval and round passes. The round steel split rolling process of the present invention solves the problem of surface defects and dimensional stability of the split wedge part of the round steel split rolling, and the surface quality of the finished product is stable, realizing the production of chain circles and standard parts by using round steel splitting And other high-quality round steel.

Description

technical field [0001] The invention relates to a round steel cutting and rolling process. Background technique [0002] At present, in the field of steel bar rolling in the iron and steel industry, the typical process methods are single-wire rolling and split rolling. Single-strand rolling is currently mainly used in the production of large-scale bars, and some production lines with relatively backward technology also use single-strand rolling. Split rolling technology has been widely used because of its outstanding advantages such as significantly improving production efficiency, reducing rolling passes, and reducing the number of rolling mills in new production lines. However, split rolling technology is rarely used on round steel. At present, domestic Only Xinjiang Bayi Steel Works has been reported. The split rolling technology has not been widely used on round steel, mainly because of the technical problems that the round steel split rolling is prone to surface defec...

AI Technical Summary

Problems solved by technology

[0003] During the production process of the above-mentioned first pass system, it is found that the produced round steel has many surface defects. The analysis is mainly because the diamond-square pass system has the following shortcomings: 1. The diamond-shaped hole is twisted 90° and enters the arc-edge square pass. , the arc-edge square hole is twisted 45° and enters the dumbbell-shaped pre-slit hole, which is prone to bite deviation, irregular material shape, poor dimensional accuracy of the finished product, and surface cracks caused by torsion. 2. Along the width direction of the pass The working diameters of the rolls in various places are quite different, so the line speed of each point on the side wall of the pass is greatly different, which causes relative sliding between the metal and the pass, thus causing additional friction between the rolled piece and the pass. 3. During rolling, the cooling rate of the corner is faster than other places, and cooling cracks are prone to appear, resulting in defects on the steel surface; 4. During the rolling process, because the four sides of the rolled piece are simultaneously It is compressed, so the oxide scale on the surface of the rolled piece is not easy to fall off, which affects the surface quality of the product

There is no report on the application of the second pass system in the round steel slitting rolling

[0004] The above problems lead to the production of common HPB300 and Q235 round bars by this diamond-square hole system, but it cannot produce high-quality round bars such as chain round bars and standard parts.

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