Modeling of the hot flow behavior and processing maps of an austenitic Fe‐30Mn‐8Al‐1C low‐density steel

Low‐density steels have an excellent combination of mechanical properties for structural applications in transportation. However, a comprehensive understanding of their hot flow behavior over wide processing windows, particularly accounting for microstructural instabilities, remains limited. The main objective of this research is to provide a comprehensive physically‐based description of the hot flow behavior and processing maps of an austenitic Fe‐30Mn‐8Al‐1C low‐density steel over a wide temperature‐strain‐rate domain, explicitly correlating hardening and softening mechanisms with microstructural instabilities induced by κ‐carbide and inclusion precipitation. The steel was manufactured via vacuum induction melting, followed by thermo‐mechanical treatment. Hot uniaxial compression tests were carried out at temperatures of 700 °C to 1000 °C and strain rates of 0.0005 s −1 to 0.1 s −1 . Physically based models were applied to derive the constitutive equations describing the hot deformation behavior, and processing maps were created using the Prasad criterion. Results show that lower temperatures and higher strain rates increase deformation resistance, while higher temperatures promote dynamic recrystallization. A good agreement was observed between experimental and modeled curves. Optimal processing conditions were identified at temperatures of 700 °C to 1000 °C and strain rates < 0.01 s −1 , while instability regions were found at 700 °C to 800 °C and strain rates > 0.01 s −1 . The presence of precipitated particles of κ‐carbides, aluminum nitrides and manganese sulfides, contributes to the plastic flow instability.