集气管线带焊缝90°弯头的冲刷腐蚀  

Erosion Corrosion of 90° Elbow Containing Welds in Gas Gathering Pipelines

作　　者：冯思乔 FENG Siqiao(Daqing Oilfield Design Institute Co.,Ltd.,Daqing 163712,China)

机构地区：[1]大庆油田设计院有限公司,大庆163712

出　　处：《腐蚀与防护》2023年第11期72-77,共6页Corrosion & Protection

摘　　要：对国内某气田集气管线带有焊缝的失效弯头进行了分析,利用Fluent软件模拟了焊缝与90°弯头处流体流型流态,分析了集气管线在该处的冲刷腐蚀机理。结果表明:焊缝和弯头外弧侧内壁处具有较高的漩涡强度,使该处腐蚀产物从金属表面剥离;受近壁面较高湍流强度的流体影响,剥离的腐蚀产物快速向主流体运移,裸露的金属基体继续被腐蚀,最终使焊缝和弯头外弧侧内壁发生严重的冲刷腐蚀。两端具有焊缝的天然气集输管线弯头,在焊缝、外弧侧内壁的冲刷腐蚀速率较高,在无内防护的服役过程中易发生腐蚀穿孔。A failure elbow containing welds in a gas gathering pipeline was analyzed.The mechanism of erosion corrosion of gas gathering pipelines at 90° elbow and weld was analyzed through simulation of fluid flow patterns at these positions in pipeline by Fluent software.The results showed that the corrosion products were peeled off from the metal surface of the weld and the inner wall of outer arc side of the elbow because of higher vortex intensity.The stripped corrosion products quickly moved to main flow under the influence of fluid with high turbulence intensity near the wall.The exposed metal matrix continued to be corroded,and finally serious erosion corrosion occurred in the weld and the inner wall on the outer arc side of the elbow.The elbow with welds at both ends in natural gas gathering and transportation pipeline had a high erosion corrosion rate in the weld and the inner wall on outer arc side,and it was prone to corrosion perforation in the service process without internal protection.

关 键 词：集气管线 弯头 焊缝 冲刷腐蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]