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Vol.40, No.12, 1298 ~ 1303, 2002
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| Title |
| Environment : Effects of Hydride Precipitation and Integrity of Oxide Layer on Accelerated Oxidation of Zircaloy-4 |
| 김용수 Yong Soo Kim , 김동주 Dong Joo Kim , 김선기 Sun Ki Kim , 조일제 Il Je Cho , 이영우 Young Woo Lee |
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| Abstract |
| The roles of the hydride precipitation and integrity of the oxide layer in the accelerated corrosion of Zircaloy-4 are investigated by determining the critical ratio of P_H2/P_H20 using TGA(Thermo-Gravimetric Apparatus) and studying the effect of hydride precipitation on the oxidation kinetics. Under hydrogen-water mixture environment hydriding reaction takes place much faster than the oxidation reaction at early stage and soon later growing oxide begins to retard the hydriding reaction and completely prevent from the hydriding in the second stage. It turns out that even in this stage the oxidation rate is enhanced with increasing P_H2/P_H20 ratio. In the final stage, the oxide breakdown occurs, thus, massive hydriding takes place again. Intermittent weight gain measurements using autoclaves also confirm these results. |
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| Key Words |
| Nuclear fuel clad materials, Zircaloy-4, Accelerated oxidation, Hydride precipitates, Hydrogen pick-up, Massive hydriding |
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