本研究主要目的為檢視316L不銹鋼與82合金所構成的異材銲接組件應用於核能電廠沸水式反應器(Boiling Water Reactor, BWR)環境中的應力腐蝕特性。試驗方法為於模擬BWR主冷卻水迴路之水化學環境中進行慢應變速率拉伸 (Slow Strain Rate Tensile, SSRT) 試驗，檢測試樣的拉伸應力應變曲線以及是否產生應力腐蝕龜裂(Stress Corrosion Cracking, SCC)，據此探討316L異材銲接試樣於BWR環境中的機械性質與SCC行為。除此之外，對其他試樣進行不同溫度的熱處理與珠擊加工並進行SSRT拉伸試驗，將結果與未經前處理的316L異材銲接試樣比對，檢測各前處理對試樣造成的影響。

試驗結果顯示，316L異材銲接試樣於BWR環境下能維持一定水準的機械性質，且不易產生IGSCC。650 ℃熱處理可使延性稍微提升，且未產生明顯的IGSCC。珠擊處理則因加工過度使強度上升，在邊緣處可發現部份IGSCC。固溶退火處理的試樣，不易產生IGSCC且延展性大幅提升，並可改善銲接熱影響區的殘留應力與元素分佈不均問題。

The primary objective of this study is to investigate the stress corrosion characteristics of dissimilar metal welds (DMWs) comprising Type 316L stainless steel as the base metal and Alloy 82 as the weld metal in simulated boiling water reactor (BWR) environments. Slow strain rate tensile (SSRT) tests were conducted to explore the mechanical properties and stress corrosion cracking (SCC) behavior of the DMWs. Some DMW samples were pretreated by shot peening and thermal treatments at different temperatures prior to the SSRT tests, and the influences of these pretreatments on the samples were examined.

Test results showed that the mechanical property of the DMW sample did not exhibit any significant difference from that of a pure 316L stainless steel sample in the same environment. Furthermore, transgranular SCC was found on the fractured surface of the sample, but no intergranular SCC (IGSCC) was observed. A post-weld heat treatment at 650 oC slightly improved the ductility of the treated DMW sample during the SSRT test. A shot peening treatment aversely led to a more serious SCC on the treated sample with distinct traces of IGSCC. A pretreatment of solution annealing resulted in a much better performance as expected for the treated sample in terms of ductility and immunity to IGSCC, since the treatment helped relieved the residual stresses and led to a more even distribution of the alloying elements in the regions adjacent to the weld.

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