Reflectance Infrared Study of the Oxidation of Stainless Steels and Component Metals

Abstract

Abstract Reflectance infrared studies of the oxidation of Types 304, 316, and 410 stainless steels, in oxygen at various temperatures, are described. Similar studies, directed toward the interpretation of the stainless steel oxide reflectance spectra, are presented for iron, nickel, molybdenum, and chromium. The value of the technique in providing a record of oxide compositional changes with time and temperature is demonstrated. It was concluded that Fe2O3 is the dominant constituent of oxide films formed on the three stainless steels at 400 to 500 C. At 850 C, chromia-iron oxide spinels, Fe2O3 and Cr2O3 were observed on Types 304 and 316 stainless steel, while chromia rich spinels or Cr2O3 formed on Type 410 stainless steel. Appreciable concentrations of nickel oxide on Types 304 and 316 stainless steel or molybdenum oxides on Type 316 stainless steel were not detected at temperatures up to 850 C. The formation of minor oxide constituents in both the stainless steel and component metal oxide films is discussed.