Method for improving plate shape quality of head portion or tail portion of hot rolling strip steel

Abstract

The invention relates to the field of plate shape control of hot rolling strip steel, in particular to a method for improving plate shape quality of a head portion or a tail portion of hot rolling strip steel. The method for improving the plate shape quality of the head portion or the tail portion of the hot rolling strip steel is characterized in that a balance state is switched to a roll bending state in advance according to time series of switch of the head portion before the head portion bites steel, and the roll bending state is switched to the balance state according to the time series of switch of the tail portion after the tail portion discharges the steel. Roll bending force which is set according to the plate shape of the head portion and the tail portion judges limitations in a switchover process. When the roll bending force exceeds a prescribed limitation, the roll bending force needs to be recalculated. A calculation principle is that the priority is given to maintaining glancing flatness of the head portion and the tail portion of the strip steel, the head portion and the tail portion of the strip steel are enabled to present micro edge waves, and the degree of convexity of the strip steel is preferably close to a target value. Compared with the prior art, the method for improving the plate shape quality of the head portion or the tail portion of the hot rolling strip steel has the advantages that calculation and judge of the roll bending force are respectively introduced to switchover time series of the head portion of the strip steel and the switchover time series of the tail portion of the strip steel, the plate shape quality of the head portion and tail portion of the strip steel is improved, ratios of steel clamping in the head portion in a finish rolling and a reeling area and steel drifting in the tail portion in the finish rolling area caused by bad shape of a tail plate are reduced.

Description

technical field [0001] The invention relates to the field of hot-rolled steel strip shape control, in particular to a method for improving the shape quality of the hot-rolled strip head or tail. Background technique [0002] In the production of hot-rolled strip steel, bending roll is an important equipment to control the shape of the strip steel plate, and it is also the only means to dynamically adjust the shape of the strip steel plate. Therefore, from the beginning of strip biting to the end of steel throwing, if the bending roll is left, the strip shape cannot be controlled. During normal production, after the steel strip bites in the finishing mill with a delay of 100 to 200 milliseconds, the balance force is converted into a bending force, and the bending force is converted into a balance force before the strip is thrown. Adjustment, the balance force is generally 70-80 tons, the bending roll is controlled by a servo valve, which can realize the flexible adjustment o...

AI Technical Summary

Problems solved by technology

The rolled finished product has about 20 to 50 meters of poor shape at the head, and about 40 to 100 meters at the tail. The probability of unqualified convexity and wave shape performance is greatly increased, and the risk of rolling is increased. , which increases the probability of steel jamming at the head of the finishing rolling area and coiling area and tail flicking of the finishing rolling area. At the same time, the coil shape of the coiling head / tail will also be affected, and poor coil shape is prone to occur. In addition, poor wave shape at the edge is very easy. Curls appear in the take-up guide, resulting in defective products

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