Effects of Neutron Irradiation on Transpassive Corrosion Behavior of Austenitic Stainless Steels

Abstract

Abstract Irradiated and unirradiated austenitic stainless steels (SS) were exposed to a transpassive potential (1,050 mVSCE) in a sulfuric acid (H2SO4) solution, and the corrosion responses were studied. Applicability of the transpassive technique to evaluation of radiation-induced segregation (RIS) of impurities was considered. The charge density during the potentiostatic transpassive test and the corrosion morphology after the test were functions of both the material chemistry and irradiation. The charge density of the unirradiated materials was correlated successfully with the bulk impurity level, as defined in terms of the parameter (wt% silicon + wt% phosphorus × 10). The charge density increased steeply above an impurity level parameter of 0.5, which corresponded to the region where intergranular attack (IGA) became visible. The change in charge density after neutron irradiation also was a function of the impurity level. Irradiation resulted in a considerable increase in charge density and grain-bou...