Microstructural evolution and mechanical properties of hot-rolled 11% manganese TRIP steel

Mechanical behaviors of transformation induced plasticity (TRIP) steels largely depend on the amount and stability of austenite. In this investigation, a large volume fraction of austenite (>65%) was produced in a hot-rolled Fe-11Mn-3.8Al-0.18C TRIP steel by solution treatment in the temperature range of 750-800 °C for 1 h. The hot-rolled alloy exhibited an excellent combination of total elongation of 35-40% and ultimate tensile strength of 880-1100 MPa and this was found to have a similar or higher level of tensile properties compared with other TRIP steels. In the meantime, less cold-rolling work or annealing time was required in the present work. The outstanding properties of the experimental steel were mainly attributed to the enhanced TRIP effect due to the large fraction of austenite. It is shown that the morphology played a more significant role than orientation in the stability of austenite.