In the present research, effect of annealing time temperature on microstructural evaluation and mechanical properties of high Mn TWIP steel with a composition of Fe-17Mn-0.6C-2Al (in %wt),during martensite reversion thermomechanical treatment has been investigated. Enhancing the mechanical properties of this steel is the main goal due to grain refinement by martensite reversion thermomechanical treatment through cryo-rolling . Therefore, for removing rolling structure and obtain equiaxed austenite structure as-received sample were annealed in 800?C for 10 minutes. then, all sample was placed in liquid nitrogen environment during 3 minutes to prepare Md30 temperature and immediately cold-rolled up to 70% thickness reduction in several pass and finally 73% strain induced martensite by plastic deformation was obtained. Then, reversion annealing in salt bath at temperature between 620-700?C and 1-100 minutes was carried out. Characterization of specimen was done by means X-ray diffraction, Vickers Hardness, feritscope, uniaxial tensile test. Optical and scanning electron microscopy were used to study structural evaluation. Microstructural and phase evaluation showed that martensite reversion in 1 minute were done completely at 620-700?C and increasing temperature causing austenite grain growth. Tensile test results show that yield and ultimate tensile strength by elevating temperature starting to reduce but ductility has increased. Considering that dynamic hall-pech has more effect in bigger grain size, falling of strength is fewer than other steels.in this work the highest yield strength and ultimate tensile strength were 690MPa and1290MPa ,respectively, that's belong to 620?C and 1minute annealing condition.
