On the oxidation of stainless steel alloy 304 in subcritical and supercritical water

The oxidized surface of stainless steel 304 was studied after being subjected to constant tensile load creep tests in water at temperatures of 200, 315 and 450 °C and for 24 h at a pressure of 27 MPa. Post-exposure morphology was studied using scanning electron microscopy while surface chemistry was analyzed through Fourier transform-infrared, Raman and X-ray photoelectron spectroscopies. In subcritical water, the formation of hematite was observed; while magnetite was found to form at a higher rate on the surfaces of samples exposed to supercritical water.