Research on the analytical model of rolling force for TiAl alloy pack rolling

Pack rolling is a hot rolling process for metals with poor plastic forming. The rolling force model is an important model for pack rolling process. Based on the E. Orowan differential equation and the characteristics of pack rolling process, the analytical model of rolling force for pack rolling process was established. Based on the established rolling force model, the influence of roll diameter, reduction rate, metal layer thickness ratio and shear yield stress ratio on the distribution of rolling stress, neutral angle and connection angle was studied. The results indicate that as the increase of reduction rate and shear yield stress ratio, and the reduction of metal layer thickness ratio, the middle layer metal is more prone to plastic deformation. The basic assumptions of the analytical model were verified through a three-dimensional finite element model. The outer layer metal and the middle layer metal were selected as 304 stainless steel and Ti-Al-2Cr-2Nb alloy for pack rolling experiments, respectively. The error between the calculated results of the analytical model and the experimental results is within 15%. The analytical model of rolling force can accurately predict the rolling force and provide theoretical guidance for the formulation of the pack rolling process.