Unique impact of ferrite in influencing austenite stability and deformation behavior in a hot-rolled Fe-Mn-Al-C steel

The unique impact of two types of ferrite, intercritical ferrite and δ-ferrite on austenite stability and deformation behavior of hot-rolled Fe-11Mn-4Al-0.2C transformation-induced plasticity (TRIP) steel were studied. Each of the two ferrites exhibited their respective role in enhancing the stability of austenite, contributing to superior ductility. An optimized quenching at 800 °C and tempering at 200 °C adopted on the as-hot-rolled steel led to a ferrite-austenite mixed microstructure that was characterized by excellent combination of tensile strength of 1082 MPa and elongation of 35%, and a three-stage work hardening behavior.