Characterization of high temperature corrosion scales on austenitic stainless steel

Abstract

The high temperature corrosion scales were characterized and analyzed by SEM and XRD techniques. The AISI 310S austenitic stainless steel was tested in wet chloride containing environment at 900 degree Celsius within horizontal tube ceramic furnace. The scales were built up on stainless steel surface. The corrosion layers were partially separated from specimen surface. SEM/EDS is an efficient tool in order to microscopically investigate scale’s microstructures and analyze chemical compositions. Then, types of corrosion scales were qualitatively identified by XRD. The results showed that the layers principally consisted of Fe and O because protective chromium oxide was destroyed by high temperature, wet condition and chloride environment. However, the split scale mainly composed of Haematite and Fe21O32 which are the oxygen rich ferrous oxides.