Pitting of AISI 304 stainless steel in bicarbonate and chloride solutions

摘要: Metastable and stable pitting on 304 stainless steel (SS304) in 0.1–0.5 m NaCl aqueous solution (pH ~8) has been investigated using a potentiodynamic, potentiostatic weak anodic current galvanostatic techniques. The addition of bicarbonate (0.025–0.5 m) to the had an inhibiting effect, manifested by shift potentials more positive values, longer induction time for reduced pit nucleation. nucleation frequency growth, metastable states, decrease as NaHCO3/NaCl molar concentration increases is no observed ratios higher than 3 (four times larger % wt NaHCO3). Pitting events never occurred at potential below −0.1 V, fewer were temperature (50°C) none chloride free solutions. behaviour oxyanions discussed.