To investigate the recrystallization behavior of large sized Nb–V microalloyed steel rods during thermomechanical controlled processing (TMCP), a series of isothermal hot compression tests were conducted on a Gleeble 1500 thermomechanical simulator. The kinetics and microstructure evolution models of dynamic recrystallization, static recrystallization, metadynamic recrystallization and the grain growth model of the tested steel were developed. Based on the developed models, a finite element (FE) model coupled with the recrystallization behavior of large sized Nb–V microalloyed steel rods during TMCP was established. Then, the distributions and evolutions of recrystallization fraction and grain size during the whole deformation process are obtained and analyzed. Finally, the predicted results were compared with experimental ones, and they show good agreement. This illustrates that the recrystallization models of the tested steel are valid and the developed FE model of large sized Nb–V microalloyed steel rods during TMCP is effective.
