Modeling and simulation of dynamic recrystallization behavior for 42CrMo steel by an extended cellular automaton method

The dynamic recrystallization (DRX) behavior of 42CrMo steel was studied by hot compressive tests and cellular automaton (CA) simulation. The experimental results showed that initial grain size besides deformation parameters has an obvious influence on dynamic recrystallization (DRX) behavior. It is found that the initial grain size not only influences the number of DRX nucleation site, but also the work-hardening (WH) coefficient, dynamic recovery (DRV) coefficient, DRX nucleation rate and grain boundary (GB) mobility. Moreover, the relationships between the WH coefficient, DRV coefficient, DRX nucleation rate, GB mobility and initial grain size can be well described by the power function. Based on the findings, the traditional CA model was extended to describe the effect of initial grain size on DRX behavior. The comparison between experimental and simulated results showed that the microstructural evolution of 42CrMo steel with different initial grain sizes during hot deformation can be accurately simulated by the extended CA model.