Theoretical research and application of the asymmetrical bending of work rolls for shape control in a cold rolling mill

An asymmetrical bending control system of work rolls was designed to decrease the asymmetrical flatness defect of a cold-rolled strip.The influence function was adopted to calculate the deformation of the roll system and the effect of the lateral flow of metal in the roll gap on the transverse tension distribution of the strip at the exit side was taken into account.When different bending forces were exerted on both ends of work rolls,the contact pressure distribution between rolls,the lateral thickness distribution and the tension stress distribution of the strip at the exit side were calculated through the iterative method.The results of theoretical analysis show that the asymmetrical bending of work rolls can improve the pressure distribution between rolls,reduce the wear and the peeling off of rolls,and decrease the asymmetrical flatness defect of the strip at the edge.The application results prove that when the actual tilt is less than 10%,a higher accuracy of flatness is obtained with asymmetrical bending than work roll tilting.