Effect of surface damage induced by cavitation erosion on pitting and passive behaviors of 304L stainless steel

The corrosion behavior of 304L stainless steel (SS) in 3.5wt% NaCl solution after different cavitation erosion (CE) times was mainly evaluated using electrochemical noise and potentiostatic polarization techniques. It was found that the antagonism effect resulting in the passivation and depassivation of 304L SS had significant distinctions at different CE periods. The passive behavior was predominant during the incubation period of CE where the metastable pitting initiated at the surface of 304L SS. Over the rising period of CE, the 304L SS experienced a transition from passivation to depassivation, leading to the massive growth of metastable pitting and stable pitting. The depassivation of 304L SS was found to be dominant at the stable period of CE where serious localized corrosion occurred.