The Influence of Grain Refinement on the Semiconducting Properties of Passive Films Formed on Ferritic Stainless Steels: A Review

Ferritic stainless steels are cheaper than austenitic stainless steels and if their behavior could be improved, both electrochemically and mechanically, they are able to rival and be substituted by a few austenitic grades in some specific usages. Numerous approaches have been utilized to produce the bulk fine-grained (FG) stainless steels so far. There are just two mechanical methods to get FG structures: procedures of advanced thermomechanical and severe plastic deformation techniques. The literature review clearly reveals the semiconducting properties of ferritic stainless steel (especially FG structures) that have been rarely investigated. So, the first aim of this paper is to review the semiconducting behaviors of the passive layers being formed on this type of stainless steels. In the following, we study influence of grain refinement on the semiconducting properties of produced passive films on FG ferritic stainless steels have been evaluated using Mott–Schottky analysis.