Superior resistance to cavitation erosion and corrosion of a novel SiC-reinforced superaustenitic stainless steel coating fabricated by high-velocity air fuel spraying

Abstract

In this work, we developed a SiC-reinforced superaustenitic stainless steel (SS) coating aimed at enhancing resistance against cavitation erosion (CE) and corrosion. Relevant results indicated that the coating exhibited a diminished mean erosion depth compared to that of 304 SS in 3.5 wt% NaCl solution. Furthermore, a pronounced inhibitory effect on the synergistic interplay between CE and corrosion was demonstrated. Electrochemical assessments underscored the superior passivation and repassivation properties of the coating during CE, contrasting markedly with the compromised passivation capacity of 304 SS, which assumed an active dissolution state characterized by a substantially elevated corrosion current density. The exceptional resistance to CE and corrosion of the coating can be attributed to its low porosity, the elevated levels of corrosion-resistant elements, and the nanoscale grain size. Consequently, this coating emerges as a highly promising candidate for the protective coating on 304 SS flow-handling components.