Corrosion Behavior of Austenitic Stainless Steel AL-6XN in Supercritical Water Environment

Corrosion behavior of AL-6XN exposed in supercritical water (SCW) at 500 ℃/25 MPa was investigated by means of gravimetry, and the structure and chemical composition of the oxide films were examined by scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and X-ray diffraction (XRD). The results show that AL-6XN approximately followed parabolic oxidation kinetics the SCW conditions. Pits can be observed on AL-6XN samples exposed in SCW. Duplex layer oxide structures under conposing of a compact inner Cr2O3/FeCr2O4 mixture layer and porous Fe3O4 outer layer developed on all samples exposed to SCW, oxide particles can be observed on sample surface.