某X52弯管泄漏失效分析  

Leakage Failure Analysis of X52 Bend Pipe

作　　者：胡志强 刘润杰 HU Zhiqiang;LIU Runjie(Pengzhou Gas Field(Marine)Development Project Department,Sinopec Southwest Oil and Gas Branch,Chengdu 610000,China;Oil and Gas Sales Centre,Sinopec Southwest Oil and Gas Branch,Deyang 618000,Sichuan,China)

机构地区：[1]中石化西南油气分公司彭州气田(海相)开发项目部,成都610000 [2]中石化西南油气分公司油气销售中心,四川德阳618000

出　　处：《焊管》2024年第6期54-61,共8页Welded Pipe and Tube

摘　　要：为了分析某X52钢级Φ325 mm×7 mm输气管道弯管段开裂泄漏原因,通过宏观观察、磁粉检测、理化性能检测、扫描电镜和能谱分析等对失效管段进行了取样分析。结果表明,该失效弯管的化学成分、拉伸性能、冲击韧性、硬度测试均不满足相关标准要求;失效弯管外弧侧裂纹源处发生氧腐蚀,在外弧侧形成点蚀坑,在材料本身的残余应力、张应力和管内内压的作用下起裂并发生扩展,当扩展到一定程度时剩余壁厚的强度无法承载导致裂纹快速扩展开裂,裂纹扩展呈脆性特征,属于应力腐蚀开裂。In order to analyze the cracking and leakage causes of X52Φ325 mm×7 mm pipeline bend pipe section,the failed pipe section is sampled by macroscopic observation,magnetic particle detection,physical and chemical properties detection,scanning electron microscopy and energy spectrum analysis.The results show that the chemical composition,tensile properties,impact toughness and hardness test of the failed pipe do not meet the requirements of relevant standards.Oxygen corrosion occurs at the crack source on the outer arc side of the failed bend pipe,forming pitting pits on the outer arc side,cracking occurs and expansion occurs under the action of the residual stress,tensile stress and internal pressure of the material itself.When the expansion reaches a certain extent,the strength of the remaining wall thickness cannot bear the load,resulting in rapid expansion cracking.The crack growth is brittle and belongs to stress corrosion cracking.

关 键 词：弯管 腐蚀 失效分析 应力腐蚀开裂 

分 类 号：TG115[金属学及工艺—物理冶金]