采用SEM和EDS对福建省某海岛上失效的35 kV钢芯铝绞线进行表面和断口的形貌观察和成分分析.结果表明,表面主要由铝,Al(OH)3和Al5(CO3)3(OH)13·xH2O等物相组成,组成的元素除了铝、氧外,还含有碳、硅、硫、氯、钠、镁、钙等.碳、硅等元素集中在表面以及距表面250~500 μm处.海洋大气、CO2和尘埃等腐蚀介质导致内层铝股线严重腐蚀,大量腐蚀产物粘附在基体上,表面上有以腐蚀区域为核心的发散裂纹.在腐蚀、振动和线张力的作用下,疲劳裂纹扩展带呈现半椭圆轮廓线,最终导致材料断裂.

The fracture surface of corroded inner Al layers of 35 KV aluminium cable steel reinforced (ACSR) conductors acrossing the 81# and 82# towers used on an island in Fujian Province was studied by SEM and EDS.The results indicated that the fatigue fracture surface was mainly composed of phases of Al,Al(OH)3 and Al5(CO3)3(OH)13·xH2O.In addition to the Al and O,C,Si,S,Cl,Na,Mg,Ca,etc existed in the surface.C,Si and other elements appeared primarily on the surface and areas about 250 μm to 500 μm away from the surface.The corrosive media such as marine atmosphere,CO2 and dust caused severe corrosion of the inner aluminum stranded wires.A large number of corrosion products adhered on the substrate and there were some divergent cracks centred on the corrosion areas.Under the effect of corrosion,aeolian vibration and line tension,corrosion areas were naturally turned into multiple corrosion fatigue sources and fatigue cracks propagated with half elliptical contour line,and eventually led the materials to fracture.