Investigations and modelling of the work hardening of as-quenched Martensite

Martensite is one of the constituents most widely used to harden the steel. A large amount of data are available in the literature to describe the relationship between the microstructure and the properties of the as-quenched martensite particularly in terms of hardness and yield stress as a function of the carbon content. Unfortunately the work-hardening mechanisms have received much less attention and they are poorly discussed in the literature. However the understanding of the stress-strain curve is relevant for a large number of applications in the microstructural engineering of high strength steels either fully martensitic or multiphase steels. This study proposes and validates a physically based model for the description of the hardening mechanisms, both isotropic and kinematic hardenings, in relation with the lath microstructure and its evolution with the carbon content.