High temperature corrosion of nanoceria coated 9Cr–1Mo ferritic steel in air and steam

In this article, air and steam oxidation resistance of bare and nanoceria coated 9Cr–1Mo ferritic steel at 650 °C for 500 h is reported. The kinetics of the oxidation process and the changes in the morphology and the chemistry for both the specimens were analyzed by backscattered electron and EPMA mapping. The nanoceria coated 9Cr–1Mo ferritic steel showed better oxidation resistance than uncoated steel under similar conditions. The thickness of the oxide scales formed on the coated samples was significantly reduced as compared to the uncoated substrates. The effectiveness of such a thin and simple nanocoating to improve the oxidation resistance of 9Cr–1Mo ferritic steel compared to the pristine is attributed to the change in the migration of cations from outward to inward diffusion of oxygen as the major mechanism.