Morphology of localised attacks on 304 austenitic stainless steel stressed by constant tensile load

Differents forms of localised etch appear on solution heat-treated austenitic stainless steel exposed to solutions of H 2 SO 4 + NaCl according to the SO 4 /Cl ratio, under well-defined experimental conditions: presence of pre-formed cavities, application of constant load, polarization to a potential in the region of imperfect passivity. The forms of etch and the effect of the various parameters are discussed.