Modeling of Metadynamic Recrystallization Kinetics and Recrystallization Mechanisms of V-Containing 12Cr Rotor Steel

In order to study the metadynamic recrystallization (MDRX) behavior of 12Cr rotor steel, the double-hit hot compression tests were performed on a Gleeble1500D thermal simulator with temperatures of 1273-1373 K, strain rates of 0.001-0.05 s−1 and inter-pass times of 5-60 s. Based on the true stress–strain curves obtained at different deformation conditions, the effects of different deformation parameters on the MDRX softening behavior are discussed. Meanwhile, the microstructure was observed using an optical microscope, electron backscatter diffraction and transmission electron microscopy. Analysis showed that recovery was the main softening mechanism, followed by recrystallization. And the bulging at the grain boundary was the fundamental nucleation mechanism for MDRX. Furthermore, the kinetics model for MDRX of 12Cr rotor steel was established, which was verified to have an accurate capability of predicting MDRX softening behavior with a correlation coefficient of R = 0.9956.