Fabrication of high-purity V-4Cr-4Ti low activation alloy products

High-purity V-4Cr-4Ti low activation alloy products, such as plates and wir es, were fabricated from the NIFS-HEAT-1 ingot with improvements of the con ventional manufacturing processes. During fabrication, significant and smal l increase in hydrogen and oxygen level were observed, respectively. Howeve r, these contaminants were released by a heat treatment at 673 K or higher in a vacuum. For the purpose of obtaining an appropriate thermomechanical t reatment condition, recrystallization behavior of plate products, which wer e 6.6, 4.0, 1.9 mm thick, was investigated after cold rolling. It was revea led that annealing at 1273 K for one to two hours provides recrystallized g rains of 20-30 mum. Only in the case of 1.9 mm-thick plates which experienc ed large degree of cross rolling, a layer of finer grain was observed in th e vicinity of the surface. The NIFS-HEAT-1 products are going through Round -robin tests by Japanese universities.