Susceptibility to intergranular corrosion in sensitized austenitic stainless steel characterized via crystallographic characteristics of grain boundaries

Failures caused by intergranular corrosion have often occurred in structures made of stainless steels, and it is necessary to establish a technique to evaluate the susceptibility to such corrosion. This study investigated the crystallographic characteristics of grain boundaries to evaluate the susceptibility. To measure the characteristics, microscopic analyses were performed by the techniques of electron backscattered diffraction and thermal etching with geometric measurements. Then, oxalic acid etching was conducted. The corrosion grooves became larger with increasing grain boundary energy, and as a result, it was found that the energy was the only variable able to characterize the susceptibility. •IGC in stainless steel was investigated based on the crystallographic characteristics of GBs.•Some of the characteristics, such as misorientation, were measured with EBSD.•GB energy was measured based on AFM measurements of thermally etched surfaces.•GB energy was concluded to be the most appropriate parameter to characterize the susceptibility to IGC.