Analysis of fracture causes for SYG type copper-aluminum transition clamp
A copper-aluminum transition clamp on the C-phase circuit breaker side of the isolation switch in a 220 kV substation was found to be broken,and a comprehensive failure analysis was conducted on the fracture causes of copper-aluminum transition clamp by means of macroscopic morphology and metallographic observations,chemical composition analysis,and fracture analysis,etc.The results show that the cracked copper-aluminum transition clamp is connected by flash welding,and there is a significant loss of material on the aluminum side due to the low melting point of aluminum,resulting in a variable cross-section welding defect with high stress concentration formed at the weld seam during the process of welding.During operation,the copper-aluminum transition clamp can withstand the bending and tensile stresses caused by the gravity of the upward line,as well as fatigue loads caused by gentle wind vibration.Under the joint action of various stresses,cracks are formed at the variable cross-section welding defect of the weld seam and gradually expand under alternating loads,leading to fatigue fracture failure of copper-aluminum transition clamp.
NETL
NSTL
万方数据
