The correlation of microstructure evolution and hardening was studied in two kinds of A533B-1 steel with high and low levels of Cu irradiated in a range of dose from 0.32 to 9.9 × 1019 n cm-2 (E > 1 MeV) under a high flux of about 1.7 × 1013 n cm-2 s-1 using three-dimensional local electrode atom probe (3DAP), positron annihilation (PA) techniques, and Vickers microhardness. The early rapid hardening was found to be caused by mainly matrix defects such as mono-or di-vacancies (V1-V2) and/or dislocations indicated by the PA analysis. The 3DAP analysis showed that dense dispersion of dilute Cu rich clusters and lean distribution of Mn-Ni-Si rich clusters, which were identified to possess the same dislocation-pinning effect by applying a Russell and Brown model, were responsible for large and small hardening in high-and low-Cu steels irradiated above 0.59 × 1019 n cm2, respectively.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Materials Science(all)
- Nuclear Energy and Engineering