304L stainless steel oxidation in carbon dioxide: An XPS study

From the early beginning of the oxidation of 304L stainless steel in carbon dioxide at 1273 K (1 min, for a weight gain of 0.02 mg cm⁻²), the surface of the alloy was entirely covered by oxides: magnetite Fe₃O₄, chromia Cr₂O₃ and traces of wüstite Fe_1−xO. Later on, for weight gains approaching 1 mg cm⁻², magnetite remained at the outer interface, with traces of hematite (Fe₂O₃), above a thick layer of wüstite Fe_1−xO. Magnetite and wüstite may favour adhesion of thermal plasma protective coatings such as alumina.