METHOD FOR CONTROLLING SEPARATION FORCE OF CASTING ROLL

摘要

A method for controlling repulsive force of casting rolls is provided to perform operation more stably and produce a casting slab with better quality as compared with an existing method by quickly opening the casting rolls to discharge the alien substances when alien substances flow in between the casting rolls and promptly restoring the casting rolls to their original positions when the alien substances flow out of the casting rolls. In a twin roll strip casting process, a method for controlling repulsive force of casting rolls comprises selectively controlling P-gain of a cylinder PID controller according to a time point when alien substances flow in between the casting rolls, a time point when the alien substances flow out of the casting rolls, and a time point when it reaches the steady state. The method comprises reducing the P-gain of the cylinder PID controller as much as a predetermined level(Kalpha) by determining a time point when a current rolls' repulsive force r(k) is maintained for a predetermined time(t1) while satisfying r(k)>=R(k)+0.3 ton relative to a past history reference line R(k) as a time point when the alien substances flow in between the casting rolls.