Irradiation hardening in F82H irradiated at 573 K in the HFIR

Post-irradiation tensile tests were conducted on alloy F82H and variants of this steels irradiated at 573 K up to 19 dpa in the High Flux Isotope Reactor (HFIR) in Oak Ridge National Laboratory. Post-irradiation tensile and hardness tests revealed that the strength of F82H steeply increased below 5 dpa, and the total elongation decreased. The ductility of the variants, which showed more ductility in the unirradiated condition was the same as irradiated F82H, even though the magnitude of irradiation hardening is smaller than F82H. This suggests that the softened parts of the blanket, such as heat affected zones, could show more ductility loss at this temperature. The hardening behavior of F82H with 0.09% additional tantalum (mod3), which demonstrated microstructural stability under high temperature processing, was very similar to that of F82H. Therefore mod3 can be an attractive alternate structural material for a blanket when processed above 1373 K.