View article

Irradiated 304 stainless steel (SS) components were harvested by the Electric Power Research Institute, US Nuclear Regulatory Commission, and members of the José Cabrera Nuclear Power Station (Zorita) in Spain. These materials are some of the most representatively aged, high-fluence SS components to date. In this study, bi-crystalline micro-tensile specimens, atom probe tomography (APT) tips, and transmission electron microscopy (TEM) lamellae were fabricated from 3 mm disks harvested from Zorita baffle plate materials irradiated to 0.05, 15 and 50 dpa to comprehensively elucidate microstructural, microchemical, and local mechanical properties changes of the material as a function of dose. TEM and APT data reveal radiation induced Ni, Cr, and Si rich precipitates in the 15 dpa sample that become smaller and partially redissolve into the matrix of the 50 dpa sample (decreasing size and number density). Dislocation loop and helium cavity number density and size were quantified as a function of dose as well as percent swelling. GB Ni and Si enrichment and Cr depletion first begins in the 15 dpa sample becoming more severe in the 50 dpa sample. Micro-tensile testing performed in the scanning electron microscope at room temperature and 300 C shows that the material’s local yield strength and ultimate tensile strength decreases with increased dose and test temperatures providing further quantitative localized strain mapping. The hardening data from the experiments in the irradiated SS were compared with the calculated values using the dispersive barrier hardening model with inputs of dislocation loops and precipitates from …