| Effects of Nb contents and test temperature on the corrosion behavior of Zr-xNb (x = 0-0.6 wt.%) binary alloys were investigated. A corrosion test was performed at 300℃, 360℃, 400℃, 450℃ and 500℃. The best corrosion resistance was observed for Zr-0.lNb at 300℃, Zr-0.2Nb at 360℃ and 400℃ and Zr-0.3Nb at 450℃ and 500℃. Nb-containing precipitates were found in the alloys containing more than 0.4 wt.% Nb before the corrosion test. After corrosion test at 400℃ for 1000 hours, however, Nb-containing precipitates were found in the alloys containing more than 0.3 wt.% Nb suggesting that Nb solubility changed with the test temperature. The superior corrosion resistance was obtained when the Nb content decreased to equilibrium solubility due to the precipitation of the supersaturated Nb in α matrix. It can be concluded that the corrosion resistance of Zr-Nb binary alloys is considerably dependant on the Nb content in α matrix and the best corrosion resistance is achieved with the Nb content of equilibrium solubility. |
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