Pre-deformation–transformation plasticity relationship during martensitic transformation

The role of pre-deformation temperature (T*) on the diffusionless martensitic phase transformation in a low alloy steel was investigated. The current results indicate that transformation plasticity strains at room temperature are often significantly underestimated in the case of combined pre-straining and superimposed stresses, if the transformation plasticity strain values obtained from separate experiments are simply superposed. However, when the difference between T* and the martensite start temperature increases no transformation plasticity strains are present following pre-deformation, and a prediction of the resulting transformation plasticity strains for a combined experiment from individual experiments is feasible. Overall, the current findings demonstrate that an accurate prediction of transformation plasticity strains strongly depends on T*. Thus, the current results emphasize the necessity of proper incorporation of T* while modelling complex production processes involving pre-deformation, superimposition of stresses and phase transformation.