Analysis of cracking and leakage of reactor oil storage tank joint pipe in a 1 000kV ultra-high voltage substation
DANG Le1, DONG Junqian1, CUI Yaru1, ZHANG Wei1, HAO Jianguo2
1. Electric Power Research Institute of State Grid Inner Mongolia Eastern Electric Power Co., Ltd, Hohhot 010000; 2. Inner Mongolia Ultra High Voltage Branch of State Grid Inner Mongolia Eastern Electric Power Co., Ltd, Xilingol, Inner Mongolia 026000
Abstract:This paper analyzes the failure of a 1 000kV reactor joint pipe cracking in the eastern region of Inner Mongolia. For identifying the causes of the cracking of the joint pipe and understanding the health status of the pipe material, a comprehensive experimental analysis is conducted on the cracked joint pipe using methods such as appearance morphology analysis, fracture analysis, digital radiography (DR) fluoroscopy detection, chemical composition analysis, metallographic microstructure detection, mechanical property detection, and strength verification calculation. The results indicated that the cracking occurres at the weld toes on both sides of the branch pipe fillet weld connected to the high- pressure measuring device on the joint pipe. The thickness deviation of the pipe wall is significant, and there are welding defects such as slag inclusion, porosity and incomplete penetration in the branch pipe fillet weld to varying degrees. The fracture of the cracked branch pipe starts from the outer wall, and most of the area on the fracture surface is an extension zone. Macroscopically, beach shaped fatigue striations can be observed in the extension zone, while microscopically, obvious fatigue bands can be observed, indicating a typical fatigue fracture. There are obvious fully decarburized layer defects on both the inner and outer surfaces of the pipe, which reduces the fatigue strength of the pipes.
党乐, 董俊谦, 崔亚茹, 张威, 郝建国. 某1 000kV特高压站电抗器储油柜联管开裂原因分析[J]. 电气技术, 2023, 24(11): 48-53.
DANG Le, DONG Junqian, CUI Yaru, ZHANG Wei, HAO Jianguo. Analysis of cracking and leakage of reactor oil storage tank joint pipe in a 1 000kV ultra-high voltage substation. Electrical Engineering, 2023, 24(11): 48-53.