在過去數十年，隨著沸水式反應器（Boiling Water Reactor, BWR）運轉時間的增長，壓力邊界組件遭受沿晶應力腐蝕龜裂(Intergranular Stress Corrosion Cracking, IGSCC)的案例更是逐年增加。欲改善應力腐蝕龜裂的現象，最直接的方法便是透過前處理，降低材料敏感性、消除材料內部的殘留應力；除此之外加氫水化學(Hydrogen Water Chemistry , HWC)，使水質呈還原性環境，降低組件材料的電化學腐蝕電位，也可更效防治IGSCC的發生。 該實驗主要針對316L不鏽鋼和52鎳基合金，進行異材銲接，評估銲道、熱影響區及接合面等區域之應力腐蝕現象。除此之外也評估銲件經固溶退火、敏化熱處理以及珠擊處理，對應力腐蝕龜裂防治的效益。試驗方式採用圓棒拉伸試樣，在模擬沸水式反應器之高溫純水中，進行慢應變速率拉伸(Slow Strain Rate Testing , SSRT)，以評估材料之機械性質；試樣拉伸後，使用掃描式電子顯微鏡，觀察材料之斷裂面形態。透過上述種種分析，研究材料之高溫抗腐蝕性質。 結果顯示，銲件經固溶退火後，敏化程度明顯降低，斷裂面完全沒更IGSCC的現象，使得延展性大幅提升。敏化熱處理後，材料的延性、強度同時下降，且隨著敏化時間增長，材料的敏化程度隨之上升，而機械性質隨之下降，即使作了加氫水化學後，也無法完全避免IGSCC。珠擊後之銲件，使材料強度以及延展性同時上升，且更效降低IGSCC的發生。 關鍵字：輕水式反應器、異材金屬焊件、應力腐蝕龜裂、殘留應力、珠擊處理、敏化處理、加氫水化學、慢應變速率拉伸。

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