Abstract: A new heat treatment was applied to a novel medium manganese transformation induced plasticity (TRIP) steel designed with the Thermo-Calc software. The proportion and stability of retained austenite were studied， and the microstructure and mechanical properties of the experimental steel were analyzed. The results showed that the tensile strength of tested steel is nearly 1000MPa， the elongation is over 30%， and the product of ultimate tensile strength and total elongation exceeds 30GPa·%. The mechanical properties are significantly influenced by the solution temperature. When the hot-rolled steels are treated at the solution temperature range of 750~800℃， the best properties are obtained.

Key words: medium manganese, TRIP steel, solution temperature, microstructure, mechanical properties