Study on asymmetrical cold rolling considered sticking friction

Abstract

A new model considered the sticking friction for analyzing the asymmetrical cold rolling process is proposed by the slab method. This friction model is composed of the Coulomb friction model and yield shear stress. The analytical models of the rolling pressure are given respectively based on Coulomb friction model, constant friction model and Orowan friction model to compare the effects of different friction models on the friction stress and rolling pressure. The proposed model can avoid the problems of the friction stress exce eding the yield shear stress in Coulomb model and the friction factor m>1in the mixed friction model. The influences of the rolling parameters on the friction stress and the proportion of the sticking zone in the deformation zone are analyzed. The results show that the proportion of the sticking zone increases with the increases of the reduction rate, friction coefficient and roll radius, and decreases with the increases of the roll speed ratio and tensions. The calculated values by the proposed model agree well with the experimental results.

Keywords

• Asymmetrical rolling
• Friction model
• Friction stress
• Sticking friction