Revealing the superplastic deformation behaviors of hot rolled 0.10C5Mn2Al steel with an initial martensitic microstructure

A hot rolled 0.10C5Mn2Al steel with an initial martensitic microstructure was tensile deformed in a temperature range of 600–1100 °C. It was found that a maximum elongation to failure of 340% and a relative high strain rate sensitivity of ~0.24–0.36 were obtained at 800 °C under an initial strain rate of 10⁻³/s. The superplasticity of the hot rolled steel was attributed to the formation of lath-typed ultrafine α + γ microduplex structure and the microstructure stabilization enhanced by substitutional element partitioning during superplastic deformation. The present results provide a promising way to develop superplastic steels with non-ideal initial superplastic microstructures.