Corrosion Behavior of Austenitic ODS Steel in Supercritical Water

Corrosion behaviors of austenitic ODS steel （316-ODS） exposed to 600 ℃/25 MPa supercritical water (SCW) were investigated. The oxidation kinetics, oxide morphology, element distribution and structure of oxide scale were characterized by weight gain measurement, SEM, EDS and XRD. The results show that 316-ODS steel exposed to SCW exhibits nodular corrosion, sensitization and exponential kinetics in weight gain. The oxide scale shows duplex structure. The inner oxide layer is Cr-riched and Fe-depleted, which mainly consists of FeCr₂O₄, while the outer oxide layer is Fe-riched and Cr-depleted, which mainly consists of Fe₃O₄.