Electrochemical Evaluation of Radiation-Induced Segregation in Austenitic Stainless Steels with Oversize Solute Addition

Effect of different levels of oversize element, cerium, on radiation-induced segregation (RIS) in type 316 stainless steel was investigated. The effect of prior cold-work on RIS was also investigated. Samples with 0.00, 0.01, and 0.04 wt.% cerium were irradiated to 0.70 dpa using 4.8 MeV protons at 300 °C. Characterization of proton-irradiated specimens was carried out using electrochemical potentiokinetic reactivation (EPR) test followed by atomic force microscopic examination. The specimen with prior cold-work (without cerium addition) showed the lowest EPR values indicating the lowest chromium depletion in this material. The specimen with 0.04 wt.% cerium showed the lower EPR value as compared to the specimen with 0.01 wt.% Ce. The irradiated specimen with prior cold-work showed linear features after the EPR tests and such features were attributed to decoration of dislocations, generated due to prior cold-work, by point defects produced during irradiation. The resistance to RIS offered by cold-work (linear features) has been more effective as compared to that by the addition of oversize solute addition.