| Improved Zr alloys for nuclear fuel cladding were designed by changing of the chemical compositions of Zircaloy-4. Both Sn and oxygen contents were varied from 0wt.% to 1wt.% and 0.1wt.% to 0.8wt.%, repectively, in order to find the optimum oxygen content to compensate the loss of strength when the Sn content reduced for improving corrosion property. As oxygen content increased from 0.1wt.% to 0.2wt.%, 0.5wt.%, 0.8wt.%, the Ultimate Tensile Strength(UTS) of specimens containing 0wt.% Sn increased by 31%, 98%, 116%. These increases appeared to be due to the effect of solid solution strengthening of oxygen. Specimens containing 0.5wt.% Sn and 1wt.% Sn showed the similar results. When Sn content decreased from 1wt.% to 0wt.%, UTS decreased by 17%. Therefore, it was concluded that the addition of 0.2wt.% oxygen could adequately make up the decrease in UTS when Sn content decreased from 1wt.% to 0wt.%. |
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