JPS6475111A - Method for controlling rolling mill in continuous rolling of metal material - Google Patents

Abstract

PURPOSE:To obtain the plate thickness of good accuracy from the tip part of a stock to be rolled by operating the friction coefft. and deformation resistance with the measured values of the rolling load, rolling torque and advance rate, and a rolling theoretial expression and controlling the roll opening and number of roll revolutions of the succeeding stock rolling time with their adaptive correction. CONSTITUTION:The load Pi<n>, torque Gi<n>, plate speed Vi, number of revolutions Ni<n> are observed at an (i) stand passing time of the tip part 1 of the stock to be rolled of an (n) coil and inputted to a setup calculator 4. The oblate roll radius R'i<n>, advance rate Fi<n> and friction coefft. mui<n> are calculated by a theoretical expression. The deformation resistance Ri<n> of an (n) coil is found by an expression and taken as Ri<n>(P) and Ri<n>(G). The friction coefft. mui<n+1> and deformation resistance Ri<n+1> under the reference rolling conditions of a (n+1) coil are calculated by an expression. Also the roll opening Sn+1 of the (n+1) coil and roll revolutions Ni<n+1> are calculated by an expression. The command values of Si<n+1>, Ni<n+1> are inputted to a rolling reduction position control device 5 and main machine speed control device 6 from a calculator 4. The plate thickness of stable rolling and good accuracy is obtd. from the tip part of the stock to be rolled and the yield can thus be improved.