Hot-rolled steel strip vertical stripe defect eliminating method

Abstract

The invention discloses a hot-rolled steel strip vertical stripe defect eliminating method. The method includes reducing the rotary speed of a grinding wheel, increasing the rotary speed of a roller during the process of rough grinding and fine grinding, reducing the rotary speed of the roller during the process of first half fine grinding, reducing the rotary speed of the roller during the processes of second half fine grinding and third half fine grinding, reducing the speed of a layer board, and reducing the contact pressure of the grinding wheel and the roller face and increasing the number of fine grinding passes. By the method, impression traces on a working roller of F4-F6 in the grinding process can be eliminated completely, and good effect can be achieved. Meanwhile, the curve radius difference of a finishing mill group end frame working roller of CVC (continuous variable crown) type is controlled in a range less than or equal to 0.75mm (0.625mm is selectable), and high grinding efficiency is improved. The hot-rolled steel strip vertical stripe defect eliminating method has the advantages of convenience in operation, significance in effect and high accuracy, and qualified raw materials are provided for producing cold rolling products, namely automobile plates, house appliance plates and the like, with high-level surface quality requirements.

Description

technical field [0001] The invention belongs to the technical field of steel rolling, in particular to a method for eliminating longitudinal stripe defects of hot-rolled strip steel. Background technique [0002] 05 Surface cold-rolled sheets are mainly used on large-area external components, such as roofs, doors, hoods, front fenders, and rear side panels of high-end cars. [0003] The so-called "05 surface" is a sign given by the German Industrial Standard DIN1623-I for the surface quality of cold-rolled sheets. It requires that the front side of the board must be free of defects and have a high-quality and uniform appearance that does not affect its coating or plating. The specific quality requirements are that if it is used as a body frame (for a 4-door car), the following defects are not allowed on the good surface of the steel plate that has not been polished by oilstone: cracks, rust (including spot rust), emulsion spots , bonding, edge damage, coiling slip, imprint...

AI Technical Summary

Problems solved by technology

As a common defect in cold rolling, longitudinal stripes on the surface of cold rolled sheets are the main reason for the reduction of the high grade rate of cold rolled sheets

This defect causes chromatic aberration on the surface of the steel plate, which leads to poor subsequent coating effects and directly affects the production of downstream processes and the use of users; in addition, this defect will also accelerate the corrosion of the steel plate, resulting in waste of resources and reduced material safety

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