Effect of stress state and temperature on the kinetics of martensitic phase transformation in TRIP-assisted steel

Abstract

The effects of the stress state and temperature on the martensitic phase transformation behavior in TRIP 780 steel were investigated using multi-axial experimental techniques. Various mechanical experiments are performed to differentiate the stress state and temperature effects. For this purpose, five different stress states were considered; i.e., uniaxial tension, uniaxial compression, equibiaxial tension, plane strain tension and simple shear. A temperatures both 25 and 60 °C for each stress state condition except the simple shear test were investigated. In-situ magnetic measurements were performed to mesure the evolution of the martensite content throughout each experiment. Finally, a new martensitic transformation kinetics model for the TRIP 780 steel is proposed to take the effect of stress state and temperature into account.