مرکز منطقه ای اطلاع رساني علوم و فناوري -

Abstract :

Several couplings between plasticity and martensitic phase transformation are at the origin of remarkable properties of ductility and toughness in the case of TRIP steels. A micromechanical model is developed to predict the conditions of nucleation and growth of a martensitic microdomain inside an inhomogeneous plastic strain field. More explicit relations are developed in the case of a simple shear test where a heterogeneous plastic strain field leads to a significant decrease of the critical stress for martensitic transformation. The obtained results are combined with a kinetics and kinematics studies to derive the constitutive equation of an austenitic single crystal from which the overall behavior of a polycrystalline steel is deduced using the self-consistent scale transition method. Comparison with experimental data shows a good agreement.