Static Recrystallization of 30Cr2Ni4MoV Ultra-Super-Critical Rotor Steel

In order to investigate the static recrystallization (SRX) behavior of 30Cr2Ni4MoV ultra-super-critical rotor steel, the double-hit hot compression tests were conducted in the deformation temperature range of (970-1250) °C, the strain rate range of (0.001-0.1) s⁻¹, and the inter-pass time range of (1-100) s. It is found that the effects of forming parameters (forming temperature and strain rate) on the microstructural evolution during SRX are not significant, while those of the initial austenitic grain size are obvious only when the initial austenitic grain size is less than 225.4 µm. Based on the experimental results, the kinetic equations have also been developed to predict the SRX behaviors of hot-deformed 30Cr2Ni4MoV steel. The proposed kinetic equation correlates well with the experimental results confirming that the proposed kinetic equations can give an accurate estimate of the static softening behaviors for 30Cr2Ni4MoV steel.