Achieving a high elongation of 1700% at low temperatures in a cold-rolled Fe-24Mn-10Al-1C lightweight steel

This study investigates the superplastic deformation behavior of cold-rolled Fe–24Mn–10Al–1C (wt.%) lightweight steels without pre–heat treatment over 600–800 °C. It achieves exceptional tensile ductility, reaching 1700% ± 30% at 700 °C and 446% at 600 °C under 10−3/s strain rate. Microstructural analysis reveals rapid dynamic recrystallization (DRX) at 700 °C and 10−3/s promotes superplastic flow, while uniformly distributed intergranular κ–carbides and phase transformation stabilize the microstructure. Microstructural analysis confirms grain boundary sliding (GBS) as the dominant superplastic mechanism. This work provides a theoretical foundation for developing superplastic high–Mn Al lightweight steels.