Recovery and recrystallization behavior of vanadium at various controlled nitrogen and oxygen levels

The effects of nitrogen and oxygen on recovery and recrystallization of vanadium were investigated using high-purity metal vanadium singly doped with nitrogen or oxygen. Nitrogen and oxygen contents ranged from 10 to 500 weight ppm (wppm) and 50 to 1000 wppm, respectively. The hardening coefficient, (ΔH/ΔC), for nitrogen is estimated to be almost twice that of oxygen. Additional hardening due to annealing at 200–400°C after rolling was observed. The anneal hardening was significantly decreased by restricting nitrogen contents below 100 wppm. On the other hand, oxygen up to 1000 wppm did not strongly affect the anneal hardening.