Abstract:
The corrosion behavior of an austenitic stainless steel 304NG exposed to supercritical water(SCW) at 500℃,550℃,600℃ and 650℃/25 MPa is investigated by means of scanning electron micro-scope/energy dispersive X-ray spectroscopy and X-ray diffraction.The surface morphology is composed of oxide islands and relative smooth base oxide.Oxide islands is a dual-layered oxide scale,which is mainly composed of an outer magnetite(Fe
3O
4) layer and an inner magnetite/spinel-mixed(Fe
3O
4/FeCr
2O
4) layer,base oxide is a single-layered magnetite/spinel-mixed(Fe
3O
4/FeCr
2O
4) oxide scale.The oxide scale has a tendency to spall,which increases with the increasing of exposure temperature.