The characterization of oxide scales formed on ferritic-martensitic steel in supercritical water with dissolved oxygen

摘要

The oxidation behaviour of ferritic-martensitic steel in supercritical water has been studied at 600 - 700 degrees C and 25 MPa. Exposure tests as functions of temperature, time and distance from the leading edge of the specimen provide evidence that hydrogen influence the surface morphology and oxide phase. Hematite is apt to develop on the top of the magnetite at a lower temperature, prolonged time, and smaller distance from the leading edge of the specimen. By the consideration of convective mass transfer, diffusive mass transport and oxidation rate, a model has been proposed to calculate the partial pressure of hydrogen.