Hot rolling wire rod production method for improving surface quality

Abstract

The invention relates to a hot rolling wire rod production method for improving the surface quality. The steps include billet preparation, heating processing, pass rolling, reducing and sizing, coil collecting and finishing. Rough rolling, intermediate rolling and pre-finish-rolling are included, the step pitch is increased during the heating processing, the box pass is adopted for billets firstly, exchange in the ellipse pass and the circle pass is then achieved, and the square billets are rolled into semi-finished products with circular fracture surfaces; the box pass, ellipse pass and circle pass combined pass is adopted for the rough rolling, the square billets are compressed under large pressure, the box pass is adopted for the first three passes of the rough rolling, box type hole base angles are increased, the ellipse pass and the circle pass are adopted for the fourth pass and the fifth pass of the rough rolling, and the circular shape is achieved after the rough rolling; and induction heating is added between the rough rolling and the intermediate rolling, and the problem that the head and tail temperature difference of red steel heads is large is solved. A spiral guide pipe is added to a lifting spiral pipe structure for the coil collecting, the circle shape of tail portions is regularized through the spiral guide pipe after the tail portions lose tension during the coil collecting, and therefore the circle shape of the tail portions is controlled and the problem that the tail portions are scratched is solved. The hot rolling wire rod production method meets the zero defect quality requirement.

Description

technical field [0001] The invention relates to a production process of a wire rod, in particular to a production method of a hot-rolled wire rod for improving surface quality. Background technique [0002] The current wire rod production process includes: material preparation, heat treatment, pass rolling, reducing and sizing machine, coil collection, controlled cooling, and finishing. There are the following technical defects in the production process: [0003] 1. The arrangement of the heating row adopts 220mm step distance, the steel billets are densely packed, there is almost no gap between the billets, the temperature of the contact part between the billet and the billet is heated slowly, and it is easy to cause temperature unevenness. [0004] 2. Existing rolling passes: 5 passes for rough rolling and 4 passes for intermediate rolling adopt box-shaped passes, that is, box-shaped passes are used for the first 9 passes of the entire rolling, and elliptical and round pa...

AI Technical Summary

Problems solved by technology

[0003] 1. The arrangement of the heating row adopts 220mm step distance, the steel billets are closely arranged, there is almost no gap between the steel billets, the temperature of the contact part of the steel billet and the steel billet is heated slowly, and it is easy to cause temperature unevenness

[0004] 2. Existing rolling passes: 5 passes for rough rolling and 4 passes for intermediate rolling adopt box-shaped passes, that is, box-shaped passes are used for the first 9 passes of the entire rolling, and elliptical and round passes are used after the 10th pass. , After the billet is heated and descaled, the rough-rolled box-shaped hole is likely to cause small deformation of the corners of the red steel, and the corners are prone to blackening

[0005] 3. When the middle rolling box shape is turned into an oval hole, the deformation is large, and the elongation coefficient reaches 1.5, resulting in uneven wear of the rolling groove, and the corners of the red steel are angular, and folding defects are prone to occur after rolling

[0006] 4. After rough rolling and tailing off, it is rolled by intermediate rolling. The temperature of the tail of red steel rolled by intermediate rolling is lower than that of the head, and there is a large temperature difference, resulting in uneven deformation of the billet.

[0007] 5. During the roll collection process, the tail part loses tension after detaching from the pinch roller, and is in a free roll collection state. The tail ring is in bad shape, and scratches with the claws of the roll collection drum and the lifting guide groove, etc.