Method for removing calibration mark of working roller of rolling mill

Abstract

The invention relates to a method for removing calibration marks of working rollers of a rolling mill. A roller change control program is added to an automatic control system of the rolling mill; an upper support roller is pre-adjusted to a middle position, and an upper working roller used for applying a positive roller-bending force and an upper middle roller are allowed to be contacted with theupper support roller; the upper working roller and the upper middle roller are rolled to a rolling position under the action of self-weight of the upper support roller; and simultaneously, the initial rolling force is adjusted to be 30% to 35% of the normal rolling force and the roller-bending force is set to be lower than 30%. Since the positive pressures, the impact forces and the rolling forces of the support rollers and the middle rollers on the working rollers and the steel strip are reduced, the calibration marks formed on the working rollers during the rolling change process and the start-up process are reduced or eliminated, and the surface quality of the steel strip is improved. Particularly, the method reduces the frequency of continuously changing the working roller, reduces the labor intensity of the operating staff, increases the work efficiency and the operating rate of the rolling mill, reduces the loss of defective products, and saves the cost by more than 0.7 million RMB per year.

Description

technical field [0001] The invention belongs to the field of steel rolling machinery and specifically relates to a method for avoiding calibration marks left in the process of changing work rolls and restarting a cold rolling mill. Background technique [0002] Most of the combined units of cold rolling mills include more than 3 cold rolling mills. The roll system of each cold rolling mill is composed of 2 work rolls, 2 intermediate rolls and 2 backup rolls; After shutting down for maintenance, it is necessary to re-calibrate the work rolls, intermediate rolls and backup rolls of the finished frame to meet the requirements of rolling precision. However, after calibration, it is often found that horizontal stripe marks perpendicular to the rolling direction are produced on the upper and lower surfaces of the work rolls, and these stripe marks will be imprinted on the surface of the strip during the rolling process, which not only directly affects the The surface quality of t...

AI Technical Summary

Problems solved by technology

However, after calibration, it is often found that horizontal stripe marks perpendicular to the rolling direction are produced on the upper and lower surfaces of the work rolls, and these stripe marks will be imprinted on the surface of the strip during the rolling process, which not only directly affects the The surface quality of the steel, and the number of continuous replacement of the work rolls is increased, which increases the labor intensity of the operators, seriously affects the operating efficiency and the output of the rolling mill, and causes great economic losses.