Method of preventing surface of strip steel from being scratched when strip steel passes through finishing mill without being rolled

Abstract

The invention provides a method of preventing the surface of strip steel from being scratched when strip steel passes through finishing mill without being rolled. By means of the fact that a hydraulic AGC cylinder of the finishing mill is accelerated and a part of upper step mat base plates are omitted, a roll gap of the finishing mill when the strip steel passes through the finishing mill without being rolled is enlarged; the angle of a front loop and the angle of a rear loop are calibrated again, and the height of the strip steel supported by the loops is increased; and meanwhile, by means of control of input of oil and water, the temperatures of mill rolls are decreased, lubricating conditions between the strip steel and the mill rolls are improved, the problem that the surface of the strip steel is scratched by the mill rolls or protective boards when the strip steel passes through the finishing mill without being rolled is resolved thoroughly, the percent of pass of quality of the strip steel is improved greatly, the percent of pass of quality of the strip steel is improved 75% to 95%, and smooth proceeding of production is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of hot-rolled strip steel, and in particular relates to a method for solving surface scratch defects of hot-rolled strip steel when a finishing mill is empty. Background technique [0002] In the production process of hot-rolled strip steel, when a major fault occurs in the finishing mill, such as damage to the motor, reducer, gearbox, AGC hydraulic cylinder, or abnormal feedback from the magnetic ruler, which causes a certain rolling mill to fail to operate normally, the rolled piece needs to be Empty from the stand mill. The empty rolling mill cannot rotate because the motor cannot rotate, so the upper and lower work rolls loaded into the rolling mill also remain in a non-rotating state. Usually, when the rolled piece is empty, the roll gap of the empty rolling mill needs to be opened to a certain roll gap value. [0003] However, when a rolling mill is empty, due to changes in rolling conditions, the low...

AI Technical Summary

Problems solved by technology

[0003] However, when a rolling mill is empty, due to changes in rolling conditions, the lower surface of the strip will scrape and scratch the lower work roll and the front and rear transition guards of the rolling mill when the original process is produced. When the rack rolling mill is empty, the front and rear loopers of the empty rolling mill cannot be put in. Under the influence of the weight of the strip, the lower surface of the strip steel at the front of the empty rolling mill will scrape against the lower work roll, while the looper at the rear of the empty rolling mill There is a risk of scratching the guard plate on the lower surface of the strip. In addition, when the rolled piece is empty, the lower work roll of the empty rolling mill is in a non-rotating state, so it is very easy to cause defects such as scratches, waxing, or even iron sheet pressing on the strip. Seriously affect the surface quality of the product and reduce the pass rate of the strip quality