The Effect of Mo on Microstructure and Mechanical properties of TWIP steel

TWIP steels are a family of high Mn austenitic steels posses both high strength and high ductility among aotumotive body steels. In the present paper, the effect of addition of Mo on improving of mechanical properties of a TWIP steel (Fe-33Mn-3Si-2Al) is investigated. To do this, different amount of Mo were added to the chemical composition of steel and the resulted mechanical properties, microstructure and crystallographic phases were examined after casting, hot rolling and annealing. The results showed that addition of Mo enhances the mechanical properties; however, the optimum strength was obtained by addition of 0.3% Mo. This resulted to a 50% increase to ultimate strength and 40% decrease in grain size.