ReflEXAFS investigation of the local atomic structure around Fe during the oxidation of stainless steel

X-ray absorption spectroscopy of the iron K edge in both surface-sensitive (total reflection) and transmission modes has been applied to a structural investigation of the early stages of the corrosion of stainless steel. Polished AISI 304 stainless steel surface, heat treated in air at 1000 degrees C, is shown to develop an iron-rich absorbing layer. After 4 min the iron is present, mainly as Fe2O3. This is preceded by the formation of another oxide phase, probably Fe3O4.