Effects of Sputtering Current on Electrochemical Corrosion Characteristics of Nanoscale Chromium Films Deposited by Direct Current Magnetron Sputtering

Chromium coatings are often used for surface treatment of metals and alloys. In this study, nanoscale chromium coatings were deposited on 316L stainless steel by direct current magnetron sputtering. The effects of sputtering currents on electrochemical corrosion behavior of nanochromium coatings were investigated in 0.5 M H²SO⁴ + 2 ppm F- solution by electrochemical methods at room temperature. Results showed that the corrosion rates for nano-chromium coatings deposited at 0.25 A, 0.35 A, and 0.4 A were lower than bare steel by more than two orders of magnitude. The chromium coatings deposited at 0.25 A were inclined to degrade in the electrolyte after long-term immersion in the electrolyte, due to lesser coverage of passivity film on chromium coating. Moreover, the chromium coatings deposited at 0.3 A and 0.4 A exhibited excellent corrosion resistance due to formation of a continuous, compact and protective passive film.