Responses of the corroded surface layer of austenitic stainless steel to different corrosive conditions under cavitation

Nanoindentation was used to measure the nano-mechanical properties of the corroded surface layer of austenitic stainless steel after cavitation corrosion tests. The phase structures and chemical compositions of the corroded surface layer were analysed using X-ray diffraction and X-ray Photoelectron Spectroscopy. The results show that corrosion caused a decrement of the nano-mechanical properties of the corroded surface layer. Once corrosion was weakened, the formation of a work-hardened layer resulted from the transformation of austenite into martensite. The synergistic effect caused the more rapid dissolution of Fe hydroxides, resulting in the enrichment of Cr and property changes of the corroded surface layer under cavitation.