Oxide films were grown on the surface of 316L stainless steel subjected to high temperatures and a high-pressure aqueous environment (250 degrees C and 7 MPa). The morphology, chemical compositions and corrosion properties of oxide films were investigated by scanning electron microscopy (SEM), auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The results indicated that oxide films formed at 250 degrees C were more corrosion resistant and thicker than were oxide films formed in air at room temperature (25 degrees C). These distinctions are correlated with the structure and chemical compositions of oxide films. It was found that both films contained a double-layer structure comprised of mixed iron-nickel oxides and chromium oxides. Iron was present as FeO, Fe2O3 and FeOOH; Cr was present as Cr2O3, Cr(OH)(3) and CrO3; and Ni existed as Ni(OH)(2) within the oxide films formed at 250 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.