Postirradiation notch ductility and fracture toughness behavior of AOD heat of alloy HT-9

Alloy HT-9 is being evaluated for potential application as a first wall material in magnetic fusion reactors. One objective of the current studies is the assessment of material notch ductility and fracture toughness in the pre- and postirradiation conditions. Charpy-V (C/sub v/) and fatigue precracked Charpy-V (PCC/sub v/) specimens of a 1.7 cm thick plate from the HT-9 reference melt (AOD process) were irradiated at 930 and at 2880C to approx. 8 x 1019 n/cm2, E > 0.1 MeV, in a water-cooled test reactor. The C/sub v/ transition temperature elevation produced by the 930C irradiation was more than three times that produced by the 2880C irradiation. The 930C irradiation data showed the alloy to be unacceptable for 930C service unless (only) elastic fracture resistance is acceptable. Good agreement was observed between C/sub v/ and PCC/sub v/ determinations of radiation-induced embrittlement