Modeling of hydrogen effects on short crack propagation in a metastable austenitic stainless steel (X2CrNi19-11)

Abstract

The experimentally observed short fatigue crack growth rate of an uncharged specimen tested in air is compared with results obtained from specimens tested in 10 MPa hydrogen atmosphere and specimens previously charged with hydrogen. To further discuss the hydrogen related short propagation mechanisms, a simulation approach for predicting short fatigue crack growth is presented. The boundary element method is used for calculating stresses and displacements in an anisotropic elastic solid. The hydrogen concentration is assumed to be homogeneously distributed in the microstructure. Based on this modelling approach, it could be concluded that hydrogen leads to an increasing short fatigue crack growth rate due to increasing irreversible deformation processes at the crack tip and also promotes grain boundary cracking in specimens tested in 10 MPa hydrogen atmosphere.