焊管2023，Vol.46Issue(12)：14-19,6.DOI:10.19291/j.cnki.1001-3938.2023.12.003
碳当量对油气输送管道环焊缝热影响区韧性的影响规律
Effect of Carbon Equivalent on Toughness of Girth Weld HAZ in Oil and Gas Transportation Pipelines
摘要
Abstract
In order to solve the problem of toughness fluctuations in the heat affected zone of high grade pipeline girth welded joints,the microstructure and mechanical properties of the experimental steel were tested using thermal simulation testing machines,metallographic microscopes,scanning electron microscopes,Vickers hardness testers,and Charpy impact testing machines.The changes in microstructure and low temperature toughness of high grade pipeline steel with different carbon equivalents after secondary thermal cycling at different peak temperatures were compared and analyzed.The results show that after secondary thermal cycling,embrittlement zone will appear in the heat affected zone of the girth welded joint,and even if the toughness of the base material is at a high level,its low temperature toughness may also decrease after multiple thermal cycles.By optimizing the design of metallurgical composition,the proportion of low toughness structures can be reduced,thereby improving the low temperature toughness of the weld heat affected zone.The differences in microstructure and morphology of different experimental steels at different temperatures indicate that the coarse granular bainite structure and many large particle M/A components are the fundamental reasons for the decrease in toughness.By studying the impression of microstructure and low temperature toughness of X80 grade pipeline steel under different heat effects,theoretical support is provided for the development and application of high toughness X80 pipeline steel suitable for fully automatic girth welding.关键词
环焊缝/热影响区/碳当量/低温韧性/M/A组元Key words
girth weld/heat affected zone/carbon equivalent/low temperature toughness/M/A component分类
金属材料引用本文复制引用
牛辉,张君,王磊,毕宗岳,崔绍华,韦奉,张鹤松,燕铸..碳当量对油气输送管道环焊缝热影响区韧性的影响规律[J].焊管,2023,46(12):14-19,6.基金项目
中国石油天然气集团有限公司"超临界二氧化碳长距离管道关键技术研究"(项目编号2021ZZ01-02) （项目编号2021ZZ01-02）
中国石油天然气集团有限公司前瞻性基础性及战略性技术攻关课题"中长距离管道纯氢/掺氢输送关键技术研究"(项目编号2021DJ(JT)). （项目编号2021DJ(JT）
