Performance Evaluation of the Corrosion Performance of Several ODS Steels Exposed to Supercritical Water

Abstract

Oxide-dispersion strengthened (ODS) steels are being considered as candidate alloys for use as primary fuel cladding material in the CANDU-SCWR. ODS steels show improved creep and radiation resistance, which make them promising candidates for the in-core applications in SCWRs. ODS alloys of austenitic stainless steels are also believed to have superior creep properties over their non-ODS counterpart materials. The supercritical water test loop at the University of New Brunswick has been used to test several ODS steels under supercritical water conditions (500^oC, 25 MPa, deaerated). The steels that were prepared by ODS processing at the Beijing University of Science and Technology were two 14% Cr steels with different minor alloying elements, one 18% Cr steel, and one 304 commercial austenitic stainless steel. The base steels were atomized, mechanically alloyed with 0.35% Y₂O₃ and consolidated, to provide for oxide dispersion strengthening. The results of the loop exposure on these ODS steels are compared to those from previous experiments, where steels were of similar composition but not ODS processed.