SURFACE OXIDATION OF TYPE 316 STAINLESS STEEL.

Abstract

Composition vs depth profiles showed Cr depletion at the topmost surface layer and Cr enrichment in the under layer. With oxidation in air at 600-800 degree C, samples showed the growth of Fe-rich surface oxide, while mechanically polished specimens generated Cr-rich oxide which had a protective nature against oxidation at lower temperatures. Once the Fe-rich oxide is nucleated on the polished specimen at higher temperatures, it grew faster than the Cr-rich oxide and spread over the initially formed oxide. Nickel plays a minor role.