Crystallographic orientation effects on pitting corrosion and pit-to-crack transition in austenitic stainless steel

Abstract This study investigates the influence of crystallographic orientation and grain boundary (GB) sensitivity on pitting corrosion and pit-to-crack transition in austenitic stainless steels, including conventionally processed and laser powder bed fusion (LPBF) conditions. A multiphysics, microstructure-sensitive phase-field framework is developed to model orientation-dependent corrosion kinetics by incorporating crystallographic Euler angles into electrochemical corrosion potentials and overpotentials, together with a GB sensitivity parameter to capture boundary-mediated corrosion effects. By integrating electron backscatter diffraction-derived microstructures, the model reproduces anisotropic corrosion morphologies, grain-selective dissolution, and texture-dependent corrosion fronts consistent with experimental observations. Coupled electrochemical–mechanical simulations reveal that the interaction between GB sensitivity and local orientation contrast governs stress localization, crack initiation location, and crack-path tortuosity. In particular, the simulations show that strongly textured LPBF microstructures develop smoother corrosion fronts than conventionally wrought materials while exhibiting distinct crack-initiation behavior, demonstrating the important role of additive-manufacturing texture in governing localized corrosion and crack-path evolution. The proposed framework provides a mechanistic basis for linking crystallographic texture, GB–controlled microstructural heterogeneity, and localized corrosion-driven cracking in stainless steels.