Hot compression behavior of advanced medium Mn steels: numerical and experimental investigation

The hot compression behavior of advanced medium-Mn steels (3–5 wt% Mn) intended for forgings was investigated using a combined experimental and numerical approaches. Finite element method (FEM) simulations were performed based on material parameters identified from stress-strain curves obtained in hot compression tests using the Gleeble thermomechanical simulator. The tests were performed in the temperature range of 900–1100 °C at a strain rate of 0.5s^-1. Color-coded maps of plastic strain distribution within the sample volume were obtained from the numerical simulations. The evolution of plastic strain in selected finite elements was analysed to monitor its changes and distribution within specific regions of the sample. The deformation behavior and yield stress of the investigated steels showed a strong dependence on temperature. At 1100 °C, dynamic recrystallization led to stress softening and the formation of a nearly equiaxed prior austenite grain (PAG).The deformation at 900 °C was governed by dynamic recovery resulting in strain hardening and a pancaked PAG morphology. The absence of dynamic recrystallization at the 900 °C was reflected in a continuous increase in von Mises stress. The grain size was significantly influenced by chemical composition. Higher Mn content promoting grain growth, while Ti and V microadditions effectively inhibit PAG coarsening. These findings provide insight into the interplay between hot deformation conditions and microstructural evolution and may support the optimization of forging processes for advanced medium-Mn steels.