Corrosion Behaviour of Chromium Implanted Type 304 Stainless Steel

Abstract

Type 304 stainless steel was modified with an ion implantation technique to obtain higher corrosion resistance. The Cr⁺ ions were implanted with acceleration energy of 50 or 180keV and with dose rates of 1-5×10¹⁷atm·cm^-2. At least 100nm surface layer was enriched with chromium more than 40at% by the implantation of 180keV. Anodic dissolution in a sulfuric acid solution was extensively suppressed for chromium implanted steels. No remarkable change, however, was observed for pitting potentials measured in a 3.5% NaCl solution, although the current before initiation of pitting was fairly suppressed for chromium implanted steels.