CONTROLLING METHOD OF PRESS-DOWN DEVIATION IN GROUP OF HOT ROLLING MILLS

摘要

PURPOSE:To reduce a gauge deviation and a camber of rolling material, by computing the changes of the sheet thickness and the gauge deviation in the longitudinal direction of the material, and performing a feed-forward controlling of the press-down and the press-down deviation of a stand which precedes a finish mill. CONSTITUTION:At the 5th stand i.e. the final stand of roughing mill, actual values of the gauge deviation (DELTAhd) and the amount of camber (x) at the exit side are inputted to a commanding circuit 26 of a comprehensive press-down deviation controlling device to compute the gauge deviation and the degree of gauge deviation. Thus the difference of roll gap DELTAH is obtained from the gauge deviation of a next or next but one rolling material at the inlet side to correct the press-down deviation at the 2nd stand by DELTAH. Further, the circuit 26 performs the press-down deviation control by computing the DELTAH and prevents a generation of meandering between the front end part and the rear end part of finishing stands and, at the central part the circuit 26 performs the press-down deviation control of the 1st stand of finish mill by DELTAH, during rolling, by putting the change of the gauge deviation (DELTAhd), in the rolling material at the exit side of the 5th stand of roughing mill, as the gauge deviation at the inlet side of the 1st stand of the finish mill, in order to eliminate the gauge deviation and the camber at the exit side of the 1st stand of the finish mill.