35kV套管线夹断裂原因分析

Analysis on Fracture Reason of 35kV Casing Pipe Wire Clamp

通过对某供电公司下属变电站主变35kV断裂套管线夹进行化学成分分析、金相检验、硬度检验、扫描电镜及能谱分析,结合该套管线夹断裂的位置和方式,综合分析了该线夹断裂的原因。结果表明:材料内部含有过多的增加虚拟锌含量的合金元素并且以大尺寸球形夹杂物的形式存在于基体中,部分以颗粒状及长条状分布于α相晶界,导致线夹脆性增加,力学性能降低,在线夹结构薄弱处发生了断裂。

The comprehensive analysis on fracture reason of 35 kV casing pipe wire clamp in a main transformer substation of a power supply company by means of chemical composition analysis, metallographic examination, hardness testing. SEM and energy spectrum analysis, combined with the fracture position and fracture mode of wire clamp. The results showed that too much alloy elements increased the virtual zinc content in the form of the largesize spherical inclusions distrihuted in the matrix, and the granular and elongated portion located in the α phase grain boundaries, leading to the increased brittleness and the decreased mechanical performance of wire clamp, at last the fracture occurred in the structure weaknesses of wire clamp.