X80M直缝埋弧焊管管体缺陷验证及分析  

Verification and Analysis of Imperfects in Pipe Body of X80M SAWL Pipe

作　　者：何小东 杨耀彬 陈越峰 齐丽华 张洪杰 HE Xiaodong;YANG Yaobin;CHEN Yuefeng;QI Lihua;ZHANG Hongjie(CNPC Engineering Materials Research Institute Co.,Ltd.,State Key Laboratory of Oil and Gas Equipment,Xi′an 710077,China;International Welding Technology Center,Xi′an 710077,China)

机构地区：[1]中国石油集团工程材料研究院有限公司油气钻采输送装备全国重点实验室,西安710077 [2]国际焊接研究中心,西安710077

出　　处：《焊管》2025年第2期31-37,共7页Welded Pipe and Tube

基　　金：国家重点研发计划“大口径油气管道柔性焊接机器人关键技术与应用示范”(项目编号2023YFB4707200)。

摘　　要：在对某天然气管道工程用X80M直缝埋弧焊管环焊缝进行相控阵超声波检测时,发现环焊接头热影响区附近存在疑似管体分层缺陷,通过不同无损检测方法对缺陷进行检测分析,借助激光共聚焦显微镜、扫描电子显微镜等对管体缺陷的宏观和微观形貌进行观察,采用能谱仪、显微硬度仪分别测试了缺陷附近的化学成分,得出了X80M管体带状组织附近的显微硬度云图,最后对缺陷的产生原因进行了分析,并提出预防措施。结果表明,X80M直缝埋弧焊管存在的疑似管体分层缺陷是因母材中心偏析形成的带状组织条状、MnS夹杂物和硬度为450HV_(0.05)的NbC、TiC长条状或块状的析出物所致,且在条状MnS夹杂物两端有微裂纹存在。为了有效改善X80连铸坯的中心偏析,避免含条状夹杂物和长条或块状析出物的带状组织形成,建议进一步优化并严格控制连铸工艺。During the phased array ultrasonic testing of the girth weld of X80M longitudinal submerged arc welded pipe for a natural gas pipeline project,it was found that there was a suspected delamination defect near the heat affected zone of the girth weld.Different nondestructive testing methods were used to verify the defect indication,the macro and micro morphology of the defects were observed by optical microscope and scanning electron microscope,composition and hardness test result of specimen near the defects were measured by energy dispersive spectrum,spark discharge atomic emission spectrometer and microhardness tester.The causes of defects were analyzed and preventive measures were put forward.Results show that the suspected delamination defect of X80M SAWL pipe is caused by the banded structure formed by the central segregation of the base material,the accompanying strip MnS inclusions and the strip or block NbC,TiC precipitates with hardness up to 450HV_(0.05),and there are micro⁃cracks at both ends of the strip MnS inclusions.To effectively improve the central segregation of X80 continuous casting slab and avoid the formation of banded structure containing strip inclusions and strip or block precipitates,it is necessary to further optimize and strictly control the continuous casting process.

关 键 词：直缝埋弧焊管 X80M 无损检测 中心偏析 带状组织 夹杂物 析出物 

分 类 号：TG115[金属学及工艺—物理冶金]