Study on Corrosion Resistance of ODS-FeCrAl Tube for ATF

Abstract

Oxide dispersion strengthened (ODS) FeCrAl alloy is one of the candidate materials for Accident Tolerant Fuel (ATF) cladding tubedue to its excellent mechanical strength, creep resistance and radiation-swelling resistance at elevated temperatures. The corrosion behaviors of ODS-FeCrAl tube with 9.5 mm outside diameter and 0.3 mm wall thickness in static water at 360 ℃ and18.6 MPa for 100 days, in flowing aqueous solution containing 1200 ppm B and 2.2 ppm Li at 360℃ and 18.6 MPa for 100 days and in steam at 1200℃ and 0.1 MPa for 8 hours, were studied herein. The morphology, composition and element distribution of oxide film were analyzed by SEM, XPS and XRD respectively. The corrosion products are mainly Fe3O4, due to the low oxygen content in both aqueous environments at 360℃. And the weight gain is 0.036 mg/cm2 and 0.36 mg/cm2, which corresponding oxide film thickness is 0.072% and 0.72% of that of tube wall respectively. In the steam at 1200℃, owing to high temperature and sufficient oxygen content, α-Al2O3 oxide film with a mean thickness of 2.34 μm is dominant on the surface, delaying further the oxidation of the matrix.No observable cracks and voids are identified on the surface and the cross section of oxide filmsin all corrosive environments.In comparison with Zr-4 reference cladding, ODS-FeCrAl tube exhibits an outstanding high temperature oxidation and corrosion resistance.