Analysis on Fracture Reason of 35 kV Casing Pipe Wire Clamp

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 large-size spherical inclusions distributed 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.