500 kV输电线路耐张线夹钢锚断裂分析

Analysis of Steel Anchor Fracture of Tension Strain Clamp on 500 kV Transmission Line

采用宏观检查、化学成分分析、力学性能测试、显微组织观察等方法分析了某500 kV线路耐张线夹钢锚断裂的原因。结果表明,钢锚断裂的原因主要是压接工艺控制不当,在第一模部位产生了应力集中;钢锚压接后加工硬化效应明显,相较压接前钢锚硬度提高了72%,达到了210HB,室温冲击韧性降低了58%,为31 J,致使钢锚抵御冲击载荷能力降低,最终在应力集中部位断裂。

The reasons for the steel anchor fracture of tension strain clamp on 500 kV transmission line were analyzed by using macro-morphology inspection,chemical composition analysis,mechanical properties test and microstructure observation.The results show that an improper cramping can result in stress concentrated in the first mold position.The steel anchor presents an obvious work hardening effect after cramping,with hardness increased by 72%to 210 HB.And its impact toughness at room temperature is reduced by 58%to 31 J.Consequently,the ability of steel anchor to resist fracture due to impact load is reduced,leading to the final failure in the stress concentration area.