An electroless plating film of palladium on 304 stainless steel and its excellent corrosion resistance

An uniform palladium film on 304 stainless steel was obtained by electroless plating. Scanning electronic microscopy, X-ray photoelectron spectroscopy, weight loss tests and electrochemical measurements were used to character the properties of the film. The palladium plated stainless steel samples showed excellent corrosion resistance in strong reductive corrosion mediums. In boiling dilute sulfuric acid solutions and boiling acetic/formic acids, corrosion rates of palladium plated 304 stainless steel samples were 3 or 4 orders of magnitude lower than the original 304 stainless steel samples. In solutions with NaCl concentration less that 0.1%, the palladium plated samples also showed better corrosion resistance. The function of palladium film on stainless steel is to raise the electrode potential and promote passivation of the steel in strong corrosive environments.