Modelling of recrystallization behavior and austenite grain size evolution during the hot rolling of GCr15 rod

In this paper, four 3-D finite element models are developed to simulate the whole rod rolling process of GCr15 steel. The distribution and evolution of different field-variables, such as effective strain, effective strain rate and temperature, are obtained. Based on the simulated results and the microstructure evolution models of the steel, the paper designs a FORTRAN program to predict the evolution of recrystallization behavior and austenite grain size in rolled piece during the rolling. The surface temperatures of rolled piece calculated by FEM agree well with measured values. Comparison between calculated values and measured ones of grain size shows the validity of the program.