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Abstract. Vanadium alloys are promising candidate low activation materials
for structural components of fusion reactors. Establishment of industrial
infrastructure is, however, remaining to be a critical issue because of lack
of other large scale commercial applications. In the present study,
technologies for large scale manufacturing of high purity V-4Cr-4Ti alloy
were developed by improving the present commercial production processes of
vanadium metal, and optimizing alloying, plating, sheeting and wiring
techniques. Efforts were focused on reducing carbon, nitrogen and oxygen
impurities, which are known to deteriorate workability, weldability and
radiation resistance of vanadium alloys. Especially, improvements were made
in atmospheric control during calcination, aluminothermic reduction, vacuum
arc remelting, and hot forging and rolling. A medium size (30kg) high purity
V-4Cr-4Ti ingot was produced and designated as NIFS-HEAT-1. The specimens
produced out of the ingot are being submitted to Round-robin tests by
Japanese universities. Two larger ingots of 166kg in total weight were
produced recently (NIFS-HEAT-2(A) and (B)). By these efforts, technology for
fabricating large V-4Cr-4Ti alloy products with
< 100ppm C,
100ppm N and
100 200ppm O was demonstrated.
IAEA 2001
