Corrosion Behavior of Steel P92 in Supercritical Water

The oxidation behavior of steel P92 exposed to supercritical water (SCW) at 500 ℃ to 600 ℃ and 25 MPa for 1000 h was investigated by means of gravimetry,SEM,EDX and XRD.The oxide scale was composed of an outer magnetite (Fe3O4) layer and an inner magnetite/spinel-mixed (Fe3O4/FeCr2O4) layer.The initial oxide scale was porous,and the pores decreased with the increase of exposure time.The oxidation rates followed the parabolic law,and increased obviously with the increase of test temperature.There were only oxidation (oxide formation) occurred under the SCW condition,without metal dissolution.