Abstract: A new quenchingtempering heat treatment method was adopted for the Fe11Mn coldrolled steels which yielded a duplex microstructure consisting of ferrite and austenite when the samples were quenched in the range of 700~800℃， leading to good combinations of tensile strength(920~1150MPa)and elongation(35%~65%). The volume fraction of austenite of the coldrolled samples before and after the tensile tests was analyzed through XRD， and it was evidenced that TRIP effects occurred during the deformation. The strain hardening behavior during the tensile tests was studied. It proved that the optimized amount of ferrite and grain size of austenite made the TRIP effects occur at the appropriate time， therefore excellent mechanical properties were obtained.

Key words: heat treatment, TRIP effects, microstructure, mechanical properties, strain hardening rate