Modifications of the stainless steels passive film induced by cerium implantation

In this work X-ray photoelectron spectroscopy studies and cyclic voltammetry are combined to elucidate the effect of Ce implantation on the formation and evolution of passive layers generated on AISI 430 and AISI 304L steels in alkaline medium. The passive films develop in implanted steels result thinner and less defective than in unimplanted. This result is interpreted in terms of a cerium-induced inhibition of the passive film re-oxidation (formation of iron and chromium oxides). The main difference between the behaviour of the two types of steel (ferritic and austenitic) seems to be related to the enrichment in nickel promoted by cerium in the outermost layer of AISI 304L.