Study on corrosion behavior of a nano carbide advanced radiation resistant austenitic stainless steels (NC-ARES)

Abstract

New type of austenitic stainless steels (SS) named ARES alloys were recently developed to achieve better corrosion and irradiation resistance, with high chromium content and high density of dislocation as well as nano-sized precipitates in the matrix. In this study, two different corrosion environments were used to evaluate the corrosion behavior of the alloy, one is the 400ºC steam exposure for 2775 h to simulate the primary system of pressurized water reactors (PWRs) and the other is a steam oxidation test at 650ºC and up to 1000 h to simulate high temperature steam environment. In addition, several commercial alloys, such as austenitic SSs and nickel-base alloy, were included in the corresponding tests to compare the results with ARES alloys. After exposure to such environments, double layer oxide structure was formed, and oxide spallation or intergranular crack were not found for ARES alloys. Furthermore, sensitization resistance of ARES alloys was evaluated by DL-EPR test after long-term exposure to susceptible temperatures. DL-EPR test results showed high resistance to sensitization for ARES alloys. Overall, ARES alloys exhibited an excellent corrosion property in various environments tested in this study.