Effect of the Intercritical Annealing Temperature on the Mechanical Properties of 10 Pct Mn Multi-phase Steel

Intercritically annealed 10 pct Mn steel has been shown to exhibit an excellent combination of strength and ductility due to the plasticity-enhancing mechanisms of mechanical twinning and strain-induced martensite transformation occurring in sequence. This mechanical behavior is only achieved for a multi-phase microstructure obtained after annealing within a specific intercritical temperature range. A model for the selection of the optimal intercritical annealing temperature was developed to achieve a high strength-ductility balance for 10 pct Mn multi-phase steel. The model considers the room temperature stacking fault energy and the thermodynamic stability of the retained austenite.