Quantitative analysis of dynamic recrystallization behavior using a grain boundary evolution based kinetic model

A theoretical model that considers the fundamental metallurgical principles of dynamic recrystallization (DRX) has been developed for hot working involving DRX. Mobile grain boundary area, immobile grain boundary area and dislocation density are introduced as state variables to describe nucleation, grain growth and impingement in DRX. The model can predict plastic flow behavior, average grain size and volume fraction of DRX. Predictions of the model are in good agreement with experimental results of an OFHC copper. It is observed that the flow stress behavior is associated with the evolution of mobile grain boundaries. The damped oscillation behavior of mobile grain boundary area at high temperatures or low strain rates leads to the oscillation of flow stress, while the over-damped behavior of mobile grain boundary area at low temperatures or high strain rates results in a monotonic peak of flow stress.