Pre-deformation-transformation plasticity relationship during martensitic transformation

Abstract

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 fora 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.