Analysis of microstructure and properties of mn-reduced trip steel at different annealing temperatures

Abstract The microstructure and properties of Mn-reduced TRIP steel at different IA temperatures were analyzed in this paper. By dilatometer, the A c1 and A c3 were measured, which are 740°C and 969°C, respectively. According to the K-M equation, 790°C is the optimal IA temperature with 24.3% RA. The samples annealed for 5 minutes at 770-830°C were characterized and tensile detection was performed. The results reveal that the rising IA temperature gives rise to cementite dissolves and the volume fraction of M/A Island increases gradually. YS and TE decrease first and then increase, YS ranges from 436 MPa to 665 Mpa, and TE ranges from 10.87% to 23.9%. UTS increases monotonically from 878 MPa to 1366 MPa. In conclusion, the sample annealed at 800°C has excellent mechanical properties (UTS=1224 MPa, TE=17.54%). Therefore, 800°C is considered to be the actual optimal IA temperature, containing 25.4% RA. This study provides a theoretical foundation for the subsequent experiment.