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| 中文摘要： | |
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本研究目的在探討還原環境對於玻璃陶瓷接合劑和金屬連接板接合件的潛變性質與破壞模式之影響，所使用的玻璃陶瓷為核能研究所開發一款代號為 GC-9 的材質，金屬連接板則是使用代號為 Crofer 22 H 的商用肥粒鐵系不銹鋼。在 800 °C 的 H 2 -7 vol% H 2 O 還原環境下，對於接合件施予剪力及張力固定負載來進行潛變實驗，同時評估還原環境時效處理對接合件潛變性質的影響，並比較在還原環境與氧化環境下潛變性質的差異。 結果顯示，接合件試片於 800 °C H 2 -7 vol% H 2 O 氣氛下的剪力與張力潛變壽命會隨著負載減少而增加。剪力試片具 1000 小時壽命的潛變強度約為剪力接合件強度的 18%，而張力試片具 1000 小時壽命的潛變強度則約為張力接合件強度的 0.67%。兩個可能影響接合件抗潛變性質的原因為：(1) 潛變實驗過程中的即時熱處理，增加 GC-9 玻璃陶瓷基材中的結晶量，並提升接合件的抗潛變能力；(2) 隨著潛變時間增加，還原環境中的水會降低 GC-9玻璃陶瓷基材中非結晶相的黏滯性，軟化接合件的結構。因此剪力與張力接合件試片的破裂位置，隨著潛變時間的增加，由破裂於 GC-9 玻璃陶瓷基材中，轉變為 GC-9 與氧化鉻(Cr 2 O 3 )的介面，最後變回破裂於 GC-9 中。 經 1000 小時還原環境時效處理後，剪力試片具 1000 小時壽命的潛變強度約為未經時效處理剪力接合件強度的 32%，而張力試片具 1000 小時壽命的潛變強度則約為未經時效處理張力接合件強度的38%。經時效處理後，接合件的抗潛變能力降低的主要原因為，在 GC-9 玻璃陶瓷基材中的玻璃相與結晶相之間形成微孔洞所導致。對於未時效處理之剪力與張力試片，在還原環境下接合件的抗潛變能力，明顯低於氧化環境下接合件的抗潛變能力，主要原因為還原環境中的水氣降低接合件的結構強度所致。
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| Abstract： | |
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The objective of this study is to investigate the effect of reducing environment on the creep properties of a joint between a glass-ceramic sealant and an interconnect steel with no and 1000-h thermal aging in a reducing environment (H 2 -7 vol% H 2 O). The joint between glass-ceramic and metallic interconnect is subjected to an applied tensile or shear constant load in reducing environment at 800 °C during the creep test. The materials used are a GC-9 glass-ceramic sealant developed at the Institute of Nuclear Energy Research (INER) and a commercial Crofer 22 H ferritic stainless steel. Comparison of the creep properties in oxidizing and reducing environments is also made for the non-aged joint. The creep rupture time of Crofer 22 H/GC-9/Crofer 22 H joint is increased with a decrease in the applied constant shear and tensile loading at 800 °C regardless of thermal aging condition. The shear and tensile creep strength of non-aged joint at 1000 h in the given reducing atmosphere is about 18% and 0.67% of the average shear and tensile joint strength, respectively. For both non-aged tensile and shear specimens with a short creep rupture time less than 10 h, fracture mainly occurs within the GC-9 glass-ceramic. For a creep rupture time of 10-100 h, fracture site changes to the interface between the Cr 2 O 3 layer and the GC-9 glass-ceramic. For a creep rupture time over 100 h, the GC-9 glass-ceramic layer is the major fracture site, again. After 1000-h thermal aging in the given reducing environment, the shear and tensile creep strength at 1000 h in H 2 -7 vol% H 2 O of the aged joint is about 32% and 38%, respectively, of that without a thermal aging. Degradation of creep strength in the joint after a thermal aging is probably due to formation of micro-voids between crystalline and glassy phases during the cooling process. The creep resistance of the non-aged joint is significantly degraded when the testing environment is changed from oxidizing environment to reducing environment. As water in the given humidified hydrogen might relax joint structure, the creep resistance of joint in reducing environment becomes weaker than that in air regardless of loading mode.
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