Passive Films on Stainless Steels −Present State of Analysis and Understanding

Abstract

Recent experimental results on the thickness, composition, conduction type, bandgap and impedance diagram of passive films on stainless steels were reviewed first. The change in conditions of passive films was shown as a function of potential. Then, the electrochemical nature of artificial passivation films that simulated the thickness and composition of passive films was introduced. The protective ability of passive films against chloride pitting was discussed in accordance with the electrochemical nature of artificial passivation films. Finally, some future subjects were proposed for the better understanding of passive films.