某变电站GIS（气体绝缘开关设备）穿墙套筒发生腐蚀穿孔导致SF₆泄漏。通过腐蚀环境分析及腐蚀产物检测，结合腐蚀发生的部位、形态，对其失效原因进行了分析。结果表明：防火包渗出的浸蚀性阴离子是诱导筒体发生电化学腐蚀的主要原因，铝合金钝化膜遭到破坏后，酸性玻璃胶释放出的醋酸使GIS穿墙套筒在酸性环境中形成钝化-活性腐蚀电池，最终发展成为严重的孔蚀。结合以往事故经验，认为GIS穿墙套筒的施工工艺在一定条件下可能导致电化学腐蚀，并依此提出防范措施。

Corrosion perforation of a GIS (gas insulated switchgear) wall bushing in a substation resulted in SF₆ leakage. The failure reasons for the GIS wall bushing were investigated through corrosion environment analysis and corrosion product detection combined with the location and morphology of corrosion. The results that the corrosive anion exuded from fire-proof package was the main cause of inducing electrochemical corrosion of the wall bushing. After the passivation film of aluminum alloy was destroyed, a passive-active corrosive cell formed on the surface of GIS wall bushing because of acidic environment constructed by acetic acid which was released by acidic glass gel, and then the corrosive cell finally became a serious pitting. According to the experience of past accidents, it was concluded that the process of GIS wall bushing could cause electrochemical corrosion under certain conditions, and some preventive measures were proposed.