The Analysis of Phase Transformation for the Prediction of Microstructure Change after Hot Forming.

Abstract

A new model of phase transformation for continuous cooling after hot forming is proposed. It is based on incremental formulation of conventional nucleation and grain growth theory, and dislocation density is introduced to describe the effect of hot forming to phase transformation. Upsetting experiments under different cooling rates, plastic strains and deformation temperatures are performed to validate the accuracy of the proposed model. The proposed model has been applied to simulate phase transformation and final microstructure after 4-pass bar rolling.