Effect of cavitation erosion induced surface damage on pitting and passivation behavior of 304L stainless steel

The corrosion behavior of 304L stainless steel (SS) in 3.5 wt.% NaCl solution after different cavitation erosion (CE) times was evaluated by electrochemical noise and potentiostatic polarization techniques. It was found that the antagonism effect between passivation and depassivation of 304L SS presented significant distinctions in different CE periods. The passivation behavior was predominant in the incubation period of CE, and the surface of 304L SS was mainly characterized by pitting initiation. During the rising period of CE, the steel experienced a process from passivation to depassivation, and a large number of metastable pitting developed into steady-state pitting. The depassivation performance is dominant in the stable period of CE, and serious local corrosion occurred on the surface of the sample.