Mathematical modeling and numerical experiments for strip shape prediction in tandem cold rolling

Abstract Shape defect is a major factor affecting the quality stability of cold-rolled strip, but due to the inherent characteristics of tandem rolling, the causes and locations of shape defects between stands cannot be determined. To address this issue, a new mathematical model has been proposed to calculate the shape defects at the exits of stands. The proposed analytical model was used to predict the shape deviations at the exit of each stand. The calculated thickness profile is basically consistent with the industrial verification results and the numerical solutions, the absolute errors of the center thickness are all within 5 µm. Comparing the results of the flatness calculations, none of the absolute errors in the calculations exceeded 2 IU. Additionally, an alternative method is provided for offline rapid calculation of actuators effect on strip shape defects. The changes in strip shape during the tandem cold rolling were clearly identified and explained. Finally, the profile of the loaded roll gap in the contact deformation zones of each stand in the tandem cold rolling, the variations in the stress distribution between the rolls, and the control efficiency of the shape actuators on the thickness profile and flatness during the tandem rolling were described and discussed.