Micromechanical Modeling of the Ratcheting Behavior of 304 Stainless Steel

Numerical simulations of 304 austenitic stainless steel (SS304) cyclic and ratcheting responses are performed using polycrystalline plasticity models. On the basis of the polycrystalline model of Cailletaud and Pilvin (1994, "Utilisation de modeles polycristallins pour le calcul par elements finis," Rev. Eur. Elem. Finis, 3, pp. 515-541), a modification of the beta rule that operates the transition between the macroscopic level and the grain level is proposed. The improvement of the transition rule is obtained by introducing a " memory variable" at the grain level, so that a better description of the local stress-strain behavior is provided. This new feature is calibrated by means of previous simulations using finite element (FE) aggregate models. The results of the updated polycrystalline plasticity model are in good agreement with the macroscopic responses.