某环焊缝开裂事故原因分析  

Failure Analysis of Cracking on Girth Weld

作　　者：张良 杨锋平 白强 吴峰 徐鹏 刘秋林 ZHANG Liang;YANG Fengping;BAI Qiang;WU Feng;XU Peng;LIU Qiulin(CNPC Tubular Goods Research Institute,Xi'an,Shaanxi 710077,China;Shaanxi Yanchang Petroleum(Group)Co.Ltd.,Yanan,Shaanxi 716000,China)

机构地区：[1]中国石油集团石油管工程技术研究院,陕西西安710077 [2]陕西延长石油(集团)有限责任公司,陕西延安716000

出　　处：《石油管材与仪器》2021年第4期36-40,共5页Petroleum Tubular Goods & Instruments

摘　　要：某输气管线在运行过程中发生环焊缝燃爆事故,该环焊缝为变壁厚焊口,位于穿越谷沟底部。为了分析环焊缝失效原因,对该环焊缝进行了性能测试、断口分析和有限元分析,并利用失效评估图对环焊缝缺陷进行了计算。结果表明:环焊缝开裂为多源脆性开裂,在管道不均匀位移、斜坡推力等附加载荷作用下,裂纹于根部未熔合和气孔等原始缺欠区域内发生启裂直至扩展失效。建议重点对类似地形位置的环焊缝开展风险排查和附加载荷治理。An explosion accident occurred in the girth weld of a gas pipeline during operation.The girth weld is a weld with variable wall thickness and is located at the bottom of the crossing valley.In order to analyze the cause of the failure,the girth weld was subjected to performance testing,fracture analysis and FEA,and the defects of the girth weld were calculated using the FAD.The results show that the girth weld cracking is multi-source brittle cracking.Under the action of additional loads such as uneven displacement of the pipeline and slope thrust,the cracks initiate in the original defect areas such as root unfused and pores and propagate to fail.It is recommended to focus on risk investigation and additional load management for circumferential welds in similar terrain locations.

关 键 词：环焊缝 失效 附加载荷 有限元 失效评估图 

分 类 号：TG404[金属学及工艺—焊接]