Microstructures and Mechanical Properties of Fe-Mn-(Al, Si) TRIP/TWIP Steels

The mechanical properties and microstructure of two low carbon high manganese steels with 23.8% (No. 1) and 33% (No. 2) (mass percent) of manganese were investigated. The results showed that No. 1 steel possesses high strength and high plasticity, and No. 2 steel has a relatively high strength and extraordinary plasticity. The No. 1 steel exhibits both TRIP (transformation induced plasticity) and TWIP (twin induced plasticity) effects during the deformation; while only TWIP effect appeared under the same deformation condition for No. 2 steel. The comparison between the microstructures and mechanical properties of two steels was made, and the strengthening mechanisms were also analyzed.