SPEED COMPENSATING METHOD FOR TANDEM ROLLING MILL

摘要

PURPOSE:To stabilize an operation and to improve product quality by correcting the circumferential speeds of upper stream and down stream stands by using the correction quantity of the roll circumferential speeds to eliminate the tension change by the mass flow change of a rolling material between the upper stream stand and the down stream stand. CONSTITUTION:The backward tension and forward tension are obtd. by adding the change rate of the rolling load arising from the change rate of the backard tension and forward tension of the down stream stand from the respective target value to the detected value of the rolling load of the down stream stand. The outlet thickness hi+1 of the down stream stand is determined from the rolling load of the down stream stand when there is no change of the rolling load by such backward tension and forward tension and the detected value of the roll gap. The correction quantity of the roll circumferential speeds of the upper stream and down stream stands to eliminate the tension change by the mass flow change of the rolling material between the upper stream and down stream stands is calculated 46 from the change rate DELTAhi+1 of the above-mentioned thickness hi+1 with respect to the outlet thickness of the down stream stand right after the engagement of the rolling material with the down stream stand, inlet thickness Hi+1, the change rate DELTAHi+1 of the inlet thickness with respect to the forward slip and the forward slip and the change rate of the forward slip right after the engagement of the rolling material with the upper stream stand. The roll circumferential speeds are corrected by such calculated quantity. The operation is thus stabilized.