鎳基182銲材之電化學再活化性質

Electrochemical Reactivation Behaviors of Alloy 182 Welds

本研究主要利用單環動電位再活化技術（single loop electrochemical potentiokinetic reactivation, SL-EPR），針對經不同熱處理之鎳基182銲材，於添加不同濃度硫代乙醯胺（CH3CSNH2）之硫酸水溶液中的電化學再活化行為進行探討。實驗結果顯示，經單環動電位再活化試驗後之鎳基182銲接原材，於晶粒內部發生枝晶間腐蝕（interdendritic corrosion）；而經620℃/24h熱處理之試片，除上述腐蝕型態外，另可觀察到沿晶腐蝕（intergranular corrosion）的發生。而藉由對經620℃/24h熱處理之鎳基182銲材試片進行定電位測試的結果，可解析出上述兩種不同腐蝕型態所發生的電位範圍及其腐蝕程度，並可藉此瞭解鎳基182銲材於再活化過程中的可能反應。

The electrochemical behaviors of Alloy 182 welds with different thermal treatments in the sulfuric acid solutions with various concentrations thioacetamide (CH3CSNH2) were investigated conducted by single-loop electrochemical potentiokinetic reactivation (SL-EPR) technique. The experimental result shows that the interdendritic corrosion was revealed after SL-EPR test for the as weld specimen. However, for the specimen with thermal treatment at 620 ℃ for 24 h, an extra intergranular corrosion was observed after the EPR test. The reactions occurred in the reactivation process for the thermal treated Alloy 182 weld could be examined and distinguished conducted by electrochemical potentiostatic tests. Thus, the corrosion degree of each reaction and its potential range occurred in the reactivation were also explored.