High temperature microstructure and mechanical properties of as-cast medium Mn steel with V addition

This research is focused on the development of a novel medium Mn steel with V-addition (0.14 wt.%), which belongs to the Advanced High Strength Steels (AHSS). In order to predict the equilibrium phases, thermodynamic simulation was used. The microstructure of the as-cast steel was composed of retained austenite, α´-martensite/α-ferrite and a very small amount of ɛ-martensite. To understand the hot flow behaviour of the as-cast steel, hot compression tests were performed at 800°C and 1000°C with a strain rate of 0.83 s−1 and 0.083 s−1, the results were compared to a V-free steel taken from the literature. A significant increase in the applied stress was observed in the samples deformed at 800°C, especially, at the strain rate of 0.083s−1. Finally, to achieve a better understanding of this behaviour, the microstructure of the V-added steel was studied after hot compression tests.