Hot Deformation Behavior of High Mn TWIP Steel Using the Processing Map

Abstract

Hot deformation behavior of 30Mn-0.5C-3.7Al-4Si TWIP steel was investigated in this study. Cylindrical specimens were used for hot compression tests at temperatures ranging from 750 to 1000°C and the strain rate range of 0.001–0.5 s⁻¹. The effect of temperature and strain rate on the flow curves was addressed. Then, processing maps of hot deformation of the steel at the selected strains of 0.5 and 0.6 were developed. In addition, standard metallography procedures were conducted on the specimens after the hot compression tests. The generated processing maps indicated that there were only one unstable region and two stable regions in which dynamic recrystallization occurred. In addition, power dissipation was generally decreased with increasing the strain, while stability flow zone was gradually expanded. In the stable region, the dynamic recrystallization zone with a maximum efficiency 0.35 at a temperature of about 1000°C and the strain rate 0.1 s⁻¹ was enlarged with increasing the strain up to 0.6. Finally, an optimum hot working condition for the TWIP steel was predicted from the processing maps.