Study of optimum composition of extra high purity Ni-Cr-W-Si alloy for advanced reprocessing plant

Ioka, Ikuo  ; Suzuki, Jun; Kiuchi, Kiyoshi; Nakayama, Jumpei*

Optimization of composition for high Cr-W-Si Ni base alloy has been studied to apply to a nitric acid with high oxidation-reduction potential of advanced reprocessing plants. The corrosion resistance of the Ni base alloy is superior to that of conventional stainless steels. In addition, The Ni base alloy has an excellent resistance of weld crack and ability of plastic deformation caused by extra high purity (EHP) refining technology. However, the Ni base alloy has a technical limitation in hot working and welding for practical use. Several Ni base EHP alloys with different content of Si and W were manufactured to choose an optimum composition range without losing corrosion resistance. High strain rate tensile tests at high temperature, corrosion tests and weldability tests were carried out to examine the optimum composition range of Ni base EHP alloy.