输电线路金具抱箍断裂原因分析

Analysis on Fractured Holt Hoop Iron of Power Transmission Line

针对某35 kV输电线路运行中发生四线抱箍断裂现象,结合断裂前服役状况,对抱箍材料的化学成分、冲击韧性及抱箍端口显微组织进行了分析,确定造成抱箍断裂的原因为:材质冲击韧性储备不大、承受弯曲应力以及焊接存在缺陷。对此,建议严格按照线路安装设计要求选取抱箍,同时加强对抱箍肋板焊接质量的监督。

The chemical composition, impact toughness and the microstructure of the fractured bolt hoop iron were analyzed combining with its actual service condition in 35 kV transmission line. The results show that the failure of the bolt hoop iron is caused by LOP（lack of penetration） defect at the end of rib. In addition, the bolt hoop iron is not very well on the material toughness. Consequently, the hoop selection is suggested to strictly perform according to the design requirements. Simultaneously, welding quality supervision management should be strengthened on the hoop installation for transmission line.