Publication | Closed Access
Semiconducting Properties of Passive Films Formed on Stainless Steels: Influence of the Alloying Elements
316
Citations
0
References
1998
Year
EngineeringMechanical EngineeringHigh Strength Low Alloy SteelThin Film Process TechnologyChemical EngineeringCorrosionThin Film ProcessingPassive Films FormedMaterials ScienceMaterials EngineeringStainless SteelsOxide ElectronicsMetallurgical InteractionBorate Buffer SolutionInner Chromium RegionAlloying ElementsElectrochemistryPassive FilmsMicrostructureSurface ScienceApplied PhysicsMetallurgical ProcessThin FilmsMetal ProcessingElectrochemical Surface Science
Passive films formed on stainless steels in a borate buffer solution (pH 9.2) have been investigated by capacitance measurements and photoelectrochemistry. The study was carried out on films formed on AISI type 304 and 316 stainless steels and high purity alloys with differing chromium, nickel, and molybdenum contents. Complementary research by Auger analysis shows that the passive films are composed essentially of an inner chromium region in contact with the metallic substrate and an outer iron oxide region developed at the film/electrolyte interface. The semiconducting properties of the passive films are determined by those of the constituent chromium and iron oxides which are of p‐type and n‐type, respectively. Thus the influence of the alloying elements on the semiconducting properties of the passive films is explained by changes in the electronic structure of each of these two oxide regions.