Hot workability, constitutive model and processing map of 3Cr23Ni8Mn3N heat resistant steel

Abstract The thermal deformation behavior of 3Cr23Ni8Mn3N heat resistant steel was studied by high–temperature thermal compression test in the deformation temperature range of 1000–1180 °C, the strain rate range of 0.01–10 s −1 and the deformation degree of 60%. The stress decreases obviously with the increase of the deformation temperature and the decrease of the strain rate. Strain-compensated Arrhenius constitutive equation of 3Cr23Ni8Mn3N was constructed. The correlation coefficient between the experimental data and the predicted data reached 0.976. It indicates that the Arrhenius constitutive equation has a high accuracy in predicting 3Cr23Ni8Mn3N. The equations between peak stress (strain), critical stress (strain) and Zener-Holomon parameters were established and there were a good linear relationship. Based on the compression test data, the power dissipation efficiency and instability maps of 3Cr23Ni8Mn3N under the strain of 0.2, 0.4 and 0.6 were established respectively. The optimum process parameters of 3Cr23Ni8Mn3N were determined by analyzing the instability area, stable area and microstructure (SEM) in the processing maps: the deformation temperature range of 1120–1160 °C, the strain rate range of 0.03–0.1 s −1 .