Influence of N, Ar and Si ion implantation on the passive layer and corrosion behaviour of AISI 304 and 430 stainless steels

Specimens of AISI 304 and AISI 430 stainless steels (SS) were implanted with nitrogen, argon and silicon up to an ion dose of 1 × 1015 ion/cm2 at an accelerating potential of 150 keV. AISI 304 and 430 SS specimens were analysed as-received and after ion implantation using X-ray photoelectron spectroscopy (XPS) in conjunction with Ar+-ion sputtering. Surface chromium enrichment was observed with the argon ion-implanted specimens compared with the non-implanted specimens, enhancing their corrosion resistance. Nitrogen implantation does not seem to have a significant effect on the structure and composition of the passive layer. Finally, silicon-implanted SSs show a very different passive layer, in which SiO2 is the main component of the outer surface.