Mechanical properties of small size specimens of F82H steel

Small specimen test technology (SSTT) has been developed to investigate mechanical properties of nuclear materials. SSTT has been driven by limited availability of effective irradiation volumes in test reactors and accelerator-based neutron and charged particle sources. In this study, new bend test machines have been developed to obtain fracture behaviors of F82H steel for very small bend specimens of pre-cracked t/2-1/3CVN (Charpy V-notch) with 20 mm length and deformation and fracture mini bend specimen (DFMB) with 9 mm length and disk compact tension of 0.18DCT (disk compact tension) type, and fracture behaviors were examined at 20 °C. The effect of specimen size on ductile–brittle transition temperature (DBTT) of F82H steel was examined by using 1/2t-CVN, 1/3CVN and t/2-1/3CVN, and it was revealed that DBTT of t/2-1/3CVN and 1/3CVN was lower than that of t/2-CVN. DBTT behaviors due to helium and displacement damage in F82H-std irradiated at about 120 °C by 50 or 100 MeV He ions to 0.03 dpa were also measured by small punch tests.