Solute interactions in pure vanadium and V-4Cr-4Ti alloy

Room temperature electrical resistivity and microhardness measurements were performed on cold-worked pure vanadium, solution annealed and cold-worked V-4Cr-4Ti alloy and fusion weld material over the isochronal annealing temperature range from 200 deg. C to 1200 deg. C. The results suggest that Ti solutes in the vanadium alloy interact with interstitial O, C and N elements at temperatures of 200 deg. C and higher. This interaction lowers the effective diffusivity of the interstitials in the alloys, which shifts the interaction of interstitials with dislocations to higher temperatures as compared to the cold-worked vanadium. Over temperature ranges associated with recovery and recrystallization, general trends showed that the hardness decreased and resistivity first decreased but then increased in each material. Microstructural changes caused by precipitation and by reduction in dislocation density during recrystallization may account for most of the differences observed in the measured properties of each material