Corrosion behavior of 9–12% Cr ferritic–martensitic steels in supercritical water

As important structural materials for advanced power plants, the corrosion of 9–12% Cr ferritic–martensitic steels exposed to both high-temperature water and supercritical water (SCW) was studied using a variety of characterization techniques. Exposure temperature and time showed significant effects on the surface morphologies, oxide scale thickness, and oxide constituents. The steels approximately followed near-parabolic oxidation kinetics in the SCW conditions. The inner spinel layer was found to be porous with a size of tens of nanometers independent upon the exposure temperature and time. High temperature accelerated the formation of a large amount of pores in the outer magnetite layer.