西南石油大学学报(自然科学版) ›› 2009, Vol. 31 ›› Issue (5): 171-174.DOI: 10.3863/j.issn.1674-5086.2009.05.038

• 石油机械工程及其它 • 上一篇    下一篇

X70管线钢焊接接头组织及其海水腐蚀规律

范舟1a 刘建仪1b 李士伦1b 张天江2   

  1. 1.西南石油大学:a.材料科学与工程学院,b.“油气藏地质及开发工程”国家重点实验室,四川成都610500;2.中国海油海洋石油工程股份有限公司,天津塘沽300452
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2009-10-20 发布日期:2009-10-20

MICROSTRUCTURE AND SEAWATER CORROSION TO WELDING JOINT OF X70 PIPELINE STEEL

FAN Zhou1a LIU Jian-yi1b LI Shi-lun1b ZHANG Tian-jiang2   

  1. 1.Southwest Petroleum University:a.School of Materials Science and Engineering,b.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu Sichuan 610500,China;2.Offshore Oil Engineering Company Ltd.,CNOOC,Tanggu Tianjin 300452,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2009-10-20 Published:2009-10-20

摘要: 对X70管线钢现场实际焊接工艺下的焊接接头,采用显微镜、电化学方法及失重法等方法和手段对母材、焊缝、热影响区进行了显微组织分析和在海水中的极化曲线、腐蚀速率的测试,研究焊接接头在模拟海水环境中的腐蚀性能。研究表明,X70管线钢焊接接头各区域组织不均匀,实验室模拟海水环境下的电化学行为、腐蚀速率存在明显差异;在海水腐蚀过程中腐蚀电位和腐蚀速率会发生变化,热影响区(HAZ)与母材及焊缝形成电偶腐蚀,接头腐蚀以点蚀为主。

关键词: X70管线钢, 焊接接头, 显微组织, 海水腐蚀, 电偶腐蚀

Abstract: The welding joint of X70 pipeline steel under certain practical welding process is studied.The microstructure of welding base metal,welding seam and HAZ of X70 pipeline steel are analyzed with microscope and elec-chemistry,the polarization curves and corrosion rate of different welding joint zones are tested in order to study the corrosion resistance property.The results show that the microstructure of different zones of welding joint is uneven,and there are obvious difference in corrosion rate and electrochemical behavior,corrosion potential and rate of different zones of welding joint change during the process of corrosion,and couple corrosion is formed between HAZ and welding base metal,at the same time,welding joint mainly exists spot corrosion.

Key words: X70 pipeline steel, welding joint, microstructure, seawater corrosion, spot corrosion

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