220 kV变电站铜铝过渡线夹腐蚀与断裂分析

Corrosion and Fracture Analysis on the Copper-aluminum Clamp in 220 kV Substation

根据220 kV南坪变电站220 kV引线夹断裂故障的调查研究,分析了铜铝过渡线夹腐蚀及开裂的原因,认为安装方式不合理是导致线夹底部焊缝发生缝隙腐蚀的主要原因;焊接质量差,在焊缝上部存在未熔合、夹渣等缺陷或施工工艺不当,导致焊缝开裂,开裂处积存电解液,铜、铝之间发生了电化学反应,使铝材逐步腐蚀缺失最终导致线夹断裂;针对铜铝过渡线夹腐蚀断裂的原因提出了整改建议及预防措施。

The reason of corrosion and crack in the copper-aluminum clamp is analyzed. The result shows that unreasonable installation is the main cause of crevice corrosion at the bottom of the weld in the clamp. Poorly welding quality, non-fusion and slag defects in the upper weld or improperly welding process are the causes of crack. Electrolyte accumulates at the part of crack and the electrochemical reacts between the copper and aluminum, which lead to the gradual corrosion of aluminum and fracture in the clamp. Finally preventive reform suggestions and measures are proposed .