Fatigue Fracture of Aluminum Wires in High-Voltage Electrical Cables in Alaska

Several wires in aluminum conductor cables fractured within 5–8 years of, service Alaskan tundra. The were comprised of 19-wire strands; the alloy 6201-T81. Visual and metallographic examinations cold-upset pressure weld joints established that fractures caused by fatigue loading attributable to wind/thermal factors at joints. grain flow was transverse wire axis, rendering notches sensitive loading. An additional contributory factor intergranular corrosion, which assisted crack initiation/propagation. failure attributed departure quality from requirements ASTM B 398 399, specify “no shall be made during final drawing or finished wire” should not closer than 15 m (50 ft). failed cable did meet either criterion. It recommended replacement inspected for strict compliance requirements.