Effect of Hydrogen and Defects on Deformation and Failure of Austenitic Stainless Steel

Austenitic stainless steels are used for a variety of applications and could suffer degradation of properties when exposed to hydrogen. The performance of these steels are also dependent on crystallographic texture which in practice is a factor influenced by manufacturing processes. A study has been performed using a crystal plasticity based finite element model to understand the effect of crystal orientation with respect to loading direction for FCC single crystals in both hydrogenated and non-hydrogenated environment. The purpose of the study is to understand the effect of crystal orientation on how hydrogen influences plastic deformation and void growth. Simulations have been performed for a variety of stress triaxilaities, Lode parmeters and hydrogen concentrations. It is observed that initial crystal orientation has a varied effect on the influence hydrogen has on plastic deformation and void growth. Hydrogen in trap distribution at various stages of the deformation process was also found to be influenced by intial crystal orientation. Hydrogen affects the evolution of crystal rotation during deformation but was not found to significantly affect the general pattern of crystal orientation evolution.