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.