材料期刊网

通过对输电线路压接金具错位型缺陷引发的失效案例进行调研，发现因耐张线夹铝管尾部与钢锚未压合致铝管内钢芯锈蚀引发的事故很多。针对两起线夹失效案例，结合宏观、脱锌与腐蚀坑检查等试验分析，和基于试验结果的仿真分析，研究了错位型缺陷及其引发的腐蚀对钢芯应力恶化、断裂的影响。结果表明，铝管尾部与钢锚未压合，钢管口钢芯应力为正常时的3．1倍，不足以使钢芯断裂。密封不良引发钢管口钢芯缝隙内腐蚀，产生蚀坑和裂纹，当蚀坑深度达到0．5 mm 时，蚀坑内最大应力为正常时的8．3倍，达到钢芯的抗拉极限。蚀坑的出现与扩展使得管口钢芯应力状态迅速恶化至断裂。研究结果对防范和诊断类似事故有着重要价值。

Through the investigation on failure cases caused by malposition defects of transmission line compression fittings,it was found that large quantity of cases were caused by the defect that the tail of aluminum pipe wasn′t pressed against the steel anchor,which led to corrosion of steel cores in the aluminum pipe.The effects of malposition defects and related corrosion on stress worsening and core fracture were studied in dealing with two clamp failure cases,combined with experimental analyses and simulation analysis.The experimental analyses mentioned above included visual inspection and the check of dezincification and corrosion pits.The analyses indicated that when the tail of aluminum pipe was not forced against the steel anchor,the stress in steel cores on steel pipe orifice was 3.1 times as high as normal,and did not reach the breaking strength.However,bad seal resulted in the crevice corrosion of steel cores,leading to appearance of pits and cracks.When the depth of corrosion pits reached 0.5 mm,the maximum stress in the pits was 8.3 times as high as normal,reaching the tensile strength of steel cores.The appearance and expansion of pits worsened the stress state of steel cores till the cores broke.The research has great value in the precaution and diagnosis of similar failures.