乡村大气环境中室外端子箱内铜导线腐蚀失效分析

Corrosion Failure Analysis of Copper Wires in Terminal Boxes in a Rural Atmospheric Environment

利用扫描电子显微镜、X射线衍射仪、X射线光电子能谱仪和离子分析,研究了乡村大气环境中变电站端子箱中铜导线腐蚀失效的原因。结果表明,导线外号码筒溶解出的Cl-加速了铜导线的腐蚀,是导致铜导线腐蚀失效的重要原因。环境中高的空气湿度是导致铜导线腐蚀的另一个关键因素。建议更换已失效铜导线,采用不溶出有害性离子材质的号码筒,并严格控制端子箱内湿度。

Sulfates and chlorides are known as common corrosion products of Cu and its alloys in rural and marine atmospheric environments,respectively.However,a large amount of Cu7Cl4(OH)10•H2O was detected in the corrosion products of Cu wires in terminal boxes in a rural atmospheric environment in Hunan province.In this paper,the corrosion failure of Cu wires in terminal boxes in the rural atmospheric environment was analyzed by means of scanning electron microscope(SEM),X-ray diffraction spectra(XRD)and X-ray photoelectron spectrometer(XPS)as well as dissolution and analysis of relevant ions.The results show that the corrosion process of the copper wire in terminal boxes is accelerated by the chlorine ion deriving from the number tubes outside the Cu wires,which is the key cause of the failure.The high relative humidity(RH)in the terminal boxes is another key-factor to accelerate the corrosion of the Cu wire.In conclusion,the present chloride-ion containing number tubes in the substation terminal boxes are suggested to be replaced as soon as possible by chloride ion-free tubes,and the relative humidity(RH)should be strictly controlled.