Enhanced mechanical properties in a high-manganese austenitic steel through formation of nano grains, nanotwinned austenite grains, nano carbides and TRIP

In this work, a specific thermomechanical treatment was used to enhance mechanical properties of a high-manganese austenitic steel. Simple uniaxial tension tests revealed that the treated steel exhibits an outstanding strength (yield strength: 970 MPa and tensile strength: 1384 MPa) and ductility (fracture strain: 37%) synergy. Microstructural studies showed that several strengthening mechanisms contribute to mechanical properties of the treated steel, including nano grains, nano twinned austenite grains, nano carbides and TRIP. Stacking fault energy and strain-induced martensitic transformation were found to have an important role in appropriate adjustment of the strengthening mechanisms to achieve the optimum properties.