Zircaloy-4 핵연료봉의 수소화합물 형성 및 파괴특성

다국어 초록 (Multilingual Abstract)

Hydride formation behavior and its effect on the mechanical properties of Zircaloy-4 nuclear cladding tube were studied. The hydride was formed by high temperature cathodic hydrogen charging method(HCM). TEM works revealed that the grain size of the commercial Zircaloy-4 cladding tubes was 2∼7㎛ in which Zr(Fe, Cr)_(2) was uniformly precipitated. δ(ZrH) spectra was mainly observed in the alloy after HCM, and, ZrH_(2) and ZrO0.35 phases were hardly observed by X-ray analysis. The hydride was found to significantly influence the mechanical properties such as ductility, ultimate tensile strength, yield strength, the crack initiation and propagation behavior. The strain rate sensitivity and the activation volume of the cladding tubes containing the hydrides were observed to be not much different from those without hydrides, suggesting the deformation mechanism before crack initiation is not greatly influenced by the presence of hydrides. The rate controlling mechanism of the deformation was well explained by the dislocation trough model in which the segregation of alloying elements on dislocation determines the activation length.

목차 (Table of Contents)

• 1. 서론
• 2. 실험방법
• 3. 결과 및 고찰
• 3-1. 수소화합물 형성 전 열처리에 따른 특성 변화
• 3-2. 수소화합물 형성 및 기계적 특성 변화
• 3-3. 파단면 관찰
• 3-4. 피복관의 변형기구
• 4. 결론
• 5. 참고문헌