Tensile testing of EP-823 and HT-9 after irradiation in STIP II

The predicted operating conditions for a lead-bismuth eutectic target to be used in an accelerator driven system for the Advanced Fuel Cycle Initiative spans a temperature range of 300-600 degrees C while being irradiated by a high energy (similar to 600 MeV) proton beam. Such spallation conditions lead to high displacement rates coupled with high accumulation rates of helium and hydrogen up to 150 appm/dpa. Two candidate ferritic/martensitic materials for these applications include HT-9 and EP-823. To investigate the effect of irradiation on these materials, the tensile properties were measured at 25, 250, and 400 degrees C after irradiation in the STIP II irradiation to doses up to 20 dpa at temperatures up to 350 degrees C. Losses in ductility concomitant with increases in yield stress are observed in both alloys although the embrittlement is more severe in the EP-823. This stronger embrittlement is attributed to the high silicon content in EP-823. Published by Elsevier B.V.