Study on Discontinuous and Continuous Dynamic Recrystallization Behavior of a High‐Mo Hot‐Work Die Steel During Hot Deformation

Hot‐work die steels exert a pronounced influence of molybdenum content on recrystallization, serving as an essential basis for optimizing hot forging parameters. Hot compression experiments were performed on a high‐Mo hot‐work die steel at 950–1250°C and 0.001–1 s −1 to investigate its characteristics during hot forging. The deformation resistance is sensitive to the compression conditions at elevated temperatures. Based on the flow stress curves, the deformation constitutive equation was constructed. The activation energy of 696 kJ/mol was higher than that of typical hot‐work die steels. Based on dynamic material theory, hot processing maps for hot‐work die steel were constructed under strain conditions of 0.3, 0.5, 0.7, and 0.9. The analysis of microstructural evolution revealed that discontinuous dynamic recrystallization (DDRX) would occur under higher strain rates and temperatures. Continuous dynamic recrystallization (CDRX) was observed by reducing temperatures and strain rates, and the recrystallization mechanism transformed into a composite mechanism in which simultaneous DDRX and CDRX occurred. The combination of microstructure and hot processing maps confirmed the optimal processing region as 1080–1120°C and 0.1–1 s −1 .