Oxidation of 800H/HT and AISI316L alloys in air and supercritical water

In this study, we evaluated the oxidation resistance of two Fe-Ni-Cr based alloys (stainless steel 316L and incoloy 800H/HT) in air and supercritical water at 600 ºC. Results indicate that Incoloy 800H/HT shows considerably better oxidation resistance in supercritical water, compared to stainless steel 316L, and therefore it is a better candidate as a structural material for SCWR. The difference in chemical composition of the alloys was found to be the main reason for better oxidation resistance of incoloy 800H/HT as it has higher amount of chromium and nickel and, on the contrary, lower amount of iron. This resulted in the formation of a protective layer on the surface which significantly retarded the oxidation in supercritical water environment.