Swelling Dependence of Neutron-Irradiated Vanadium Alloys on Temperature, Neutron Fluence, and Thermomechanical Treatment

Swelling of vanadium alloys was determined after irradiation at 420 and 600°C to neutron fluences ranging from 0.3 × 10²⁷ neutrons/m² (17 dpa) to 1.9 × 10²⁷ neutrons/m² (114 dpa). Binary and ternary vanadium alloys with Cr, Ti, Mo, W, Ni, Fe, Zr, and Si additions were irradiated in either the fully annealed, partially annealed, or 10% cold-worked condition. Upon irradiation at 600°C, the swelling of vanadium to which Cr had been added was greatly exacerbated, whereas the swelling of vanadium to which Ti, Mo, W, and Ni (3–20%) had been added was not significantly affected. The swelling of V-Cr alloys upon irradiation at 600°C was substantially reduced (<0.1%/dpa) by the addition of Ti (1–15%). Upon irradiation at 420°C the swelling of the vanadium alloys was <0.2%/dpa. Partial annealing or 10% cold-working had an insignificant effect on swelling of the alloys.