Passivation behavior and surface chemistry of Fe-based amorphous coating in NaCl solution: Influence of applied potential and immersion time

The influence of the potential for film formation and immersion time on the corrosion resistance of the passive film formed on Fe-based amorphous coating was thoroughly investigated. The semiconducting properties and chemical composition of the passive films were analyzed employing Mott-Schottky and XPS techniques. Results indicate that the stability of the film diminished as the potentials and immersion periods increased. The structural properties and chemical composition of film played a crucial role in the corrosion resistance of the coating in a chloride electrolyte. The accumulation of cation vacancies and the formation of metal chlorides increased the likelihood of film rupture, ultimately leading to pitting. •Reveal the effect external environmental conditions on the characteristics of the passive film.•The corrosion resistance of passive film is independent of the thickness.•Reveal the effect of passive film structure and composition on the coating's corrosion resistance.•The formation of a cation vacancy condensate and solid metal chloride lead to failure of the passive film.