石油化工油气管道焊接接头断裂韧性评定  

Fracture toughness evaluation of welded joints of petrochemical oil and gas pipeline

作　　者：李磊 LI Lei(CPEC Project Management Company Tianjin Design Institute,Tianjin 300457,China)

机构地区：[1]中国石油北京项目管理公司天津设计院,天津300457

出　　处：《焊接技术》2023年第6期103-107,I0006,共6页Welding Technology

摘　　要：评定了石油化工油气管道焊接接头断裂韧性,为今后石油化工油气管道质量提升、改进提供全新的研究思路。选取壁厚15,20,25 mm的石油化工油气管道常用X80等径管材,使用熔化极气体保护焊与双面多丝埋弧焊相结合的焊接方式,分别制备AJ-1,AJ-2,AJ-3 3种焊接接头试验试件。使用CTOD断裂韧性分别测定3个试件焊缝中心、熔合线、热影响区的裂纹顶端张开位移,并使用扫描电子显微镜观察各试件断裂微观形貌,分析各试件断裂韧性受裂纹扩展量影响情况。试验结果显示:裂纹扩展量会导致焊接接头裂纹顶端张开位移增大,影响焊接接头的韧性。3种焊接接头试件的不同区域裂纹顶端张开位移均>0.15 mm,断裂韧性较高;微观形貌结果显示,壁厚为15 mm的试件AJ-1热影响区韧窝较小,且出现较大解理面,脆性与韧性断裂特征都较为明显,该试件在焊缝中心与熔合线的韧窝较小,断裂韧性较低;壁厚为20 mm的试件AJ-2在热影响区存在准解理形貌,断裂韧性降低。在焊缝中心区的韧窝斜拉区断裂韧性升高,在熔合线出现较多剪切唇,断裂韧性并不理想;壁厚为25 mm的试件AJ-3在焊接接头各个区域均出现较多大韧窝,尤其焊缝中心的韧窝中出现第二相粒子,证明试件AJ-3的断裂韧性最高。To evaluate the fracture toughness of welded joints of petrochemical oil and gas pipelines,and to provide a new research direction for improving the quality of petrochemical oil and gas pipelines in the future.X80 isodiameter pipes commonly used in petrochemical oil and gas pipelines of 15,20,25 mm were selected,and AJ-1,AJ-2 and AJ-3 welded joints test specimens were prepared by the welding method combining consumption electrode gas protection welding and double-sided multi-wire submerged arc welding.CTOD fracture toughness was used to measure the crack tip opening displacement values in the weld center area,the fusion line area and the heat affected zone of the three specimens,and scanning electron microscopy was used to observe the fracture microstructure of each specimen,and analyze the influence of crack expansion amount on the fracture toughness of each specimen.The test results showed that crack expansion would lead to the increase of crack tip opening displacement of welded joints and affect the toughness of welded joints.The crack tip opening displacement in different areas of the three welded joints was higher than 0.15 mm,indicating high fracture toughness.The microstructure results showed that the specimen AJ-1 with a wall thickness of 15 mm had a smaller dimple in the heat-affected zone and a larger cleavage plane,and the britle and ductile fracture characteristics were more obvious.The specimen had a smaller dimple in the weld center area and the thermal fusion line area,and the fracture toughness was low.The specimen AJ-2 with a wall thickness of 20 mm had a quasi-cleavage morphology in the heat affected zone,which reduced the fracture toughness.In the center of the weld,the dimple cable tension appeared,and the fracture toughness increaseed,and more shear lips appeared in the fusion line area,which was not ideal.The AJ-3 specimen with a wall thickness of 25 mm had many large dimples in each area of the welded joint,and the second phase particles appeared in the dimples in the center area of the we

关 键 词：石油化工 油气管道 焊接接头 断裂韧性 CTOD 双面多丝埋弧焊 

分 类 号：TE832[石油与天然气工程—油气储运工程]