Analytical Modeling of Thermo-Mechanically Induced Residual Stresses of Work Rolls during Hot Rolling

An analytical model is set up to predict the surface-near thermo-mechanical stresses in work rolls during hot rolling. The quantification of the temperature distribution and the residual stresses in circumferential direction allow for an optimization of the rolling process in order to reduce banding. Besides influences of mechanical loading, banding is primarily caused by high temperature differences between the roll's surface and colder layers underneath the surface. Since a steady-state is not reached in the relevant time domain the model accounts for the instationary case. Calculated thermally induced residual stresses are related to the mechanical properties of the roll's material. Analytically calculated temperature distributions on the roll surface are predicted by the model and compared with experimental results. The influence of the rolling speed and strip temperature are discussed with respect to plastic strains in circumferential direction of the roll.