| Abstract |
| To investigate the microstructural change with aging treatment and the effect of microstructure on the oxidation characteristics of Zr-xNb alloys, the TEM study. the oxidation test, and oxide characterization were performed, The specimens having different Nb content in the range from 0.1 to 2 wt.％were heat-treated at 570℃ from 0 to 1000 hours to observe the process of phase transformation after β-quenching. The oxidation test was performed in water at 360℃ and the oxide characteristics of the oxidized specimens were investigated by using low-angle XRD. The oxidation behavior of Zr-xNb alloys was affected hy the soluble Nb and the second phases in the matrix. The oxidation rate was lower when the Nb content was in the equilibrium soluble state in matrix when the β_(Nb) phase was formed by aging treatment. From the oxide analysis, the soluble Nb and the β_(Nb) phase appeared to stabilize the tetra-ZrO_(2) while the supersaturated Nb in the matrix may accelerate the transformation of oxide crystal structure from the tetra-ZrO_2) to mono-ZrO_(2). |
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| Key Words |
| Zr, Zr-Nb, Aging, Microstructure, βNb phase, Corrosion, Oxide, Tetra-ZrO2, Mono-ZrO2 |
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