Passive film properties of Z3CN20.09M duplex stainless steel aged for different times

Abstract

The protectiveness and characterization of the passive film formed on Z3CN20.09M duplex stainless steel aged for different times were investigated by using electrochemical measurements and surface analysis method. The thermal aging causes the spinodal decomposition of the ferrite phase in the steel, resulting in the decrease of localized corrosion resistance. The increased aging time causes a thicker, dispersive, and lower resistance passive film formed on the surface of the steel based on EIS and Mott–Schottky (MS) analysis. The Auger electron spectroscopy (AES) and X‐ray photoelectron spectroscopy (XPS) results indicate that Cr is enriched in the inner layer of the passive films with a reduced content, decreasing the compactness and homogeneity of the passive films.