Corrosion Behaviour of Alloy 800H in Low Density Superheated Steam

Abstract

The integrity of materials is of great concern in the construction of nuclear reactors. During the design of Gen IV supercritical water reactors, materials characterization under simulated conditions must be carried out to aid proper material selection. In this study, the long term corrosion resistance of Alloy 800H under low pressure superheated steam (SHS) at a temperature of 800°C and 0.1 MPa was tested for up to 3000 hours. The results showed that all six samples experienced weight gain in the first 2000 hours while both weight gain and weight loss were found after 3000 hours. Visual inspection and SEM surface analysis suggest the likelihood of oxide exfoliation at a later stage of the testing in SHS. Additionally, chromia formed on all samples after 1000, 2000 and 3000 hours as well as spinel and hematite.