Effect of Ni on the Natural Passivating Film and Pitting Corrosion Resistance of Stainless Steels in Alkaline Media

Abstract

This work addresses the influence of Ni on the natural passivation process of stainless steels (SSs) in alkaline media simulating concrete pore solution by a combination of electrochemical and X-ray photoelectron spectroscopy (XPS) surface analysis. It was found that the involvement of Ni in the passive film on the SS promoted Fe depletion at the passive film/substrate interface and increased the content of Cr oxide during natural passivation, thereby enhancing the corrosion resistance of the passive film. The passive film with Ni has a higher breakdown potential and can be more easily re-passivated compared with a passive film without Ni.