Advances in the Study of Passive Films on Stainless Steels: from Real to Artificial Passive Films and Now from Artificial to Real Passive Films

Abstract

Studies of passive films on stainless steels are reviewed from the viewpoint of developing new resources-saved stainless steels (green stainless steels). Starting from the overview of the results of in-situ analyses for the thickness and chemical composition of real passive films, there are describing some important findings obtained from the model experiments using artificial passive films and ion-beam-sputter deposited Fe-Cr thin films, which simulate real passive films and ideal stainless steels, respectively. Finally, recent studies on the pit initiation mechanism at sulfide inclusions and on the improvement of pitting resistance by removal of the inclusions from steel surface are introduced to demonstrate a possibility of developing green stainless steels.