ZIRCONIUM ALLOY COMPOSITION FOR NUCLEAR FUEL CLADDING TUBE

PROBLEM TO BE SOLVED: To improve the corrosion resistance and strength of a tube and to make the tube usable for a member in an atomic furnace core by allowing it to have a compsn. contg. Nb, Sn, one among Mo, Cu and Mn, and O and the balance Zr. SOLUTION: The alloy compsn. is composed of, by weight, 0.3 to 0.6% Nb, 0.7 to 1.0% Sn, one element selected from the group consisting of Mo, Cu and Mn by 0.05 to 0.4%, 600 to 1,400 ppm O, and the balance Zr. Nb is a β phase stabilizing element Zr and is furthermore excellent in hydrogen absorptivity and the improvement of strength. Sn works as an α phase stabilizing element for a Zr alloy to improve its strength. Mo improves its strength and creep characteristics. Cu and Mn improve its corrosion resistance. O improves its mechanical strength by solid solution strengthening. Moreover, by adding 0.2 to 0.5% Fe and 0.05 to 0.25% Cr thereto, its corrosion resistance can furthermore be improved.