Are Cr3C2-25(80Ni20Cr) coatings deposited by HVOF suitable for reciprocating sliding contacts under aqueous media?

To evaluate the wear performance of a Cr3C2-25(80Ni20Cr) in several corrosive media, coatings were deposited by High Velocity Oxy-Fuel (HVOF) thermal spraying on 316L stainless steel (SS) substrates. Ball-on-plate reciprocating wear tests were performed on both coating and substrate in air, double-distilled de-aerated water, 3.5 wt% NaCl, 0.2 M NaOH and 0.2 M H2SO4 solutions. Tribocorrosion tests were performed under open circuit potential, potentiodynamic and cathodic protection conditions. The results showed that the coating has a wear resistance comparable to 316L in distilled water, NaOH and NaCl solutions. For H2SO4, the coating showed significantly improved wear resistance relatively to SS.