Effect of hot deformation parameters on microstructure evolution mechanism and workability in a wear-resistance steel of machinery equipment

Abstract

Hot compression experiments were conducted to study the flow behavior and hot workability of NM400 wear-resistance steel. A new Zener-Hollomon parameter ( Z) model is developed for coupling strain into the conventional Z model. The NM400 exhibits excellent resistance to instability owing to its low sensitivity to unsafe regions. Conversely, the peak efficiency of the power dissipation (EPD) region expands to the direction of low temperature with increasing of strain. The dynamic recrystallization (DRX) is facilitated at elevated temperatures and lower strain rates. DRX becomes the dominant softening mechanism with the increasing of temperature. Finally, 1050–1175 °C and 0.11–1.82 s−1 are recommended to be the optimal window. The optimal ln Z values for different strains are provided by the new Z model.