Shape control strategy by bending force combination adjustment for 6-hi cold rolling mill

A shape control strategy by bending force combination adjustment for 6-hi cold rolling mills was proposed to solve the theoretical insufficiency of 4-order shape defect control by two kinds of bending forces. A roll-strip coupling model was established with Marc finite element simulation software, and the difference of shape control characters was analyzed between work roll bending force and intermediate roll bending force. Two methods for implementing the shape control strategy, which are the on-line closed-loop control model and the on-line setting parameter adjustment method based on bending force combination coefficients, were introduced by theoretical derivation. It is proved by field application that with the shape control strategy, the difference of shape control characters between work roll bending force and intermediate roll bending force is fully utilized and the combination adjustment is realized to precisely control 4-order shape defects, which perplex production for a long time.