MICROSTRUCTURAL EVOLUTION UNDER DUAL-ION IRRADIATION AND IN-REACTOR CREEP OF TYPE-316 STAINLESS-STEEL WELDED-JOINTS

Electron beam (EB) welding was applied to 316SS and the titanium modif ied 316SS (JPCA). For the prospective improvement of swelling in welde d joints, modified TIG or EB welding procedures utilizing titanium or nickel foil insertion were employed. For the case of EB welding of 15 mm thickness I-butt joint, the higher weld heat input showed better sw elling resistance in the joints. The in-reactor creep results suggest that irradiation creep in welded joints may not be a big concern, as f ar as swelling resistance is maintained. So, Ni addition, stress relie f treatment and high heat input for EB welding with optimization of we lding condition are recommended for suppressing irradiation creep and swelling.