Electrochemical and A.E.S. studies of FeCr surface alloys formed on AISI 52100 steel by ion beam mixing

FeCr surface alloys have been formed on AISI 52100 steel by ion beam mixing in order to improve localized corrosion resistance. Three implant species were considered in this work, namely: Cr⁺, Xe²⁺ and Kr²⁺. Ion implanation was carried out on Cr surface layers, of 30 and 50 nm, deposited onto 52100 steel coupons. The resulting surface alloys were chemically characterized by Auger electron spectroscopy. Electrochemical pitting studies were carried out in deaerated 0.01 M NaCl solution buffered to pH 6. Each of the surface alloys formed by the ion beam mixing technique exhibited a significantly higher resistance to localized corrosion compared to 52100 steel. The possbile influence on the localized corrosion resistance of the surface alloys of oxidation, carbide formation and sputtering, resulting from the ion implantation treatments, is discussed.