Tensile and impact properties of vanadium-base alloys irradiated at

Abstract

Tensile and impact properties were investigated at <430°C on V–Cr–Ti, V–Ti–Si, and V–Ti alloys after irradiation to ≈2–46 dpa at 205–430°C in lithium or helium in the fast flux test facility (FFTF), high flux isotope reactor (HFIR), experimental breeder reactor II (EBR-II), and advanced test reactor (ATR). A 500-kg heat of V–4Cr–4Ti exhibited high ductile–brittle transition temperature and minimal uniform elongation as a result of irradiation-induced loss of work-hardening capability. Work-hardening capabilities of 30- and 100-kg heats of V–4Cr–4Ti varied significantly with irradiation conditions, although the 30-kg heat exhibited excellent impact properties after irradiation at ≈390–430°C. The origin of the significant variations in the work-hardening capability of V–4Cr–4Ti is not understood, although fabrication variables, annealing history, and contamination from the irradiation environment are believed to play important roles. A 15-kg heat of V–3Ti–1Si exhibited good work-hardening capability and excellent impact properties after irradiation at ≈390–430°C. Helium atoms, either charged dynamically or produced via transmutation of boron in the alloys, promote work-hardening capability in V–4Cr–4Ti and V–3Ti–1Si.