High temperature oxidation of a CrN coating deposited on a steel substrateby ion plating

A Cr0.644N0.356 coating was deposited on a steel substrate by are-ion plati ng. The oxidation characteristics of the deposited coating, which was compo sed of CrN and Cr2N phases, were studied at temperatures ranging from 700 t o 950 degreesC in air. The coating displayed good oxidation resistance up t o 950 degreesC. The oxidation product was primarily Cr2O3, which contained some dissolved nitrogen and the substrate element of iron. The unreacted co ating beneath the oxide scale had some dissolved oxygen and iron. The oxida tion of the Cr0.644N0.356 coating occurred via complex routes such as predo minant outward diffusion of chromium, nitrogen and iron and inward transpor t of oxygen. (C) 2001 Elsevier Science B.V. All rights reserved.