Improvement of localized corrosion resistance of austenitic stainless steel by N, Cr and Mo ion implantation

Type 304 and type 316 stainless steel were modified using an ion implantation technique in order to improve their localized corrosion resistance, that is, pitting corrosion and crevice corrosion in chloride solutions. N⁺, Mo⁺ and Cr⁺ ions were implanted on these steels. It is observed that the pitting corrosion resistance was not improved by ion implantation without any pre or post treatment on the surface. Improvement of localized corrosion was obtained when the surface was slightly dissolved after ion implantation. Furthermore, electrolytic polishing before implantation was proved to be also favorable for inhibition of pitting corrosion