压气站X70钢管与A694F60材质阀门对接焊缝裂纹成因分析  

Analysis on the Cause of Crack in the Butt Girth Weld between X70 Steel Tube and A694F60 Material Valve in Compressor Station

作　　者：张冰 ZHANG Bing(Oilfield Management Department of No.1 Oil Production Plant,Daqing Oilfield Co.,Ltd.)

机构地区：[1]大庆油田有限责任公司采油一厂油田管理部,163001

出　　处：《油气田地面工程》2021年第9期77-85,共9页Oil-Gas Field Surface Engineering

摘　　要：针对某天然气压气站内阀门与袖管对接环焊缝多个裂纹的成因问题,采用宏观形貌、无损检验、化学成分分析、拉伸性能测试、夏比冲击性能测试、硬度测试、金相分析等方法,结合现场实际情况,对环焊缝及其裂纹进行了系统分析。分析结果表明:1^(#)、2^(#)、3^(#)、6^(#)裂纹均位于焊缝中心,裂纹中部和裂纹末端存在明显的疏松组织和颗粒状枝晶间断裂形貌,是典型的焊接热裂纹特征,为焊接过程中产生的焊接缺陷;4^(#)、5^(#)裂纹均位于阀门侧焊趾处,由外表面向焊缝内部扩展,裂纹附近存在马氏体等硬脆组织,在内压、焊接残余应力等载荷作用下开裂并扩展。Aiming at the causes of multiple cracks in girth weld between valve and liner in a natural gas compressor station,macro morphology,non-destructive testing,chemical composition analysis,tensile performance testing,Charpy impact performance testing,hardness testing,metallographic anal-ysis and other methods are adopted,combining with the actual situation on site,the girth weld and girth weld crack are systematically analyzed.The analysis results show that the 1^(#),2^(#),3^(#),6^(#)cracks are all located in the center of the weld,and there are obvious loose structures and granular interdendritic fracture morphologies in the middle and the end of the crack,which are typical characteristics of weld-ing hot cracks.It is a welding defect produced in the welding process.4^(#)and 5^(#)cracks are all located at the side welding toe of the valve,extending from the outer surface to the inside of the weld.There are hard and brittle structures such as martensite near the cracks,which crack and expand under loads such as internal pressure and welding residual stress.

关 键 词：压气站 环焊缝及裂纹 焊接热裂纹 残余应力 

分 类 号：TE974[石油与天然气工程—石油机械设备] TG441.7[金属学及工艺—焊接]