220 kV GIS终端环氧套管开裂原因分析  

Cause analysis of Cracking of Epoxy Casing in 220 kV GIS Terminal

作　　者：张杰 周宇通 罗宏建 赵洲峰 沈利 王磊 孙庆峰 刘学广 ZHANG Jie;ZHOU Yutong;LUO Hongjian;ZHAO Zhoufeng;SHEN Li;WANG Lei;SUN Qingfeng;LIU Xueguang(Electric Power Research Institute of State Grid Zhejiang Electric Power Company,Hangzhou 310014,China;Zhejiang Zheneng Electric Power Co.,Ltd.,Hangzhou 31007,China;State Grid Ningbo Electric Power Supply Company,Zhejiang Ningbo 324000,China)

机构地区：[1]国网浙江省电力公司电力科学研究院,杭州310014 [2]浙江浙能电力股份有限公司,杭州310007 [3]国网浙江省电力有限公司宁波供电公司,浙江宁波324000

出　　处：《高压电器》2021年第6期240-245,共6页High Voltage Apparatus

基　　金：国家电网公司科技项目(输变电设备金属材料选用、制造及安装工艺要求及设备部件检测方法研究)。

摘　　要：为分析某220 kV变电工程户外GIS终端环氧套管开裂原因,首先对失效样品和完好样品进行了宏观检查、渗透检测,确定了裂纹的形态及分布,然后采用力学性能试验、膨胀系数测定、红外光谱FTIR检测、SEM、EDS等确定了材料的抗拉强度、膨胀系数、成分、微观颗粒度等。研究表明,套管开裂均起源于嵌件螺母孔边缘,环氧树脂制造过程中产生固化收缩应力,在温差作用下由于环氧树脂与嵌件螺母膨胀系数差异导致在螺母嵌件与环氧树脂的拐角处叠加产生的附加应力,以上二者是导致套管开裂的主要原因;另外,环氧树脂中存在的微观组织颗粒大小不均匀也是导致裂纹的可能原因。结论,可通过改善固化工艺减小收缩应力、改进环氧树脂配方提高组织性能、嵌件采用圆滑过渡面减小应力等措施防止套管开裂。In order to analyze the reasons for the cracking of B-phase epoxy sleeve in outdoor GIS terminal of a 220 kV substation project,the failure samples and intact samples were examined by macroscopical inspection and penetration detection,and the shape and distribution of the cracks were determined.Then the tensile properties of the materials were determined by mechanical properties,expansion coefficient determination,FTIR detection,SEM,EDS and so on.Strength,coefficient of expansion,composition,micro-particle size,etc.The results show that the cracking of the casing originates from the edge of the nut hole of the insert.The curing shrinkage stress occurs in the manufacturing process of epoxy resin.Under the action of temperature difference,the additional stress caused by the superposition of the corner between the nut insert and the epoxy resin is caused by the difference of the expansion coefficient between the epoxy resin and the insert nut.The above two factors lead to the cracking of the casing.Major countries:In addition,the uneven size of micro-structure particles in epoxy resin is also a possible cause of cracking.Conclusion:The cracking of casing can be prevented by improving curing process,reducing shrinkage stress,improving epoxy resin formulation,improving structure and properties,and adopting smooth transition surface to reduce stress.

关 键 词：GIS终端 环氧树脂 开裂 膨胀系数 应力集中 组织不均匀 

分 类 号：TM216.5[一般工业技术—材料科学与工程]