20号钢环焊缝中夹杂物对氢扩散行为影响  

Effects of inclusions in steel 20 girth weld on hydrogen diffusion behaviors

作　　者：李玉星[1,2] 宁元星 刘翠伟 王财林[1,2] 张慧敏 LI Yuxing;NING Yuanxing;LIU Cuiwei;WANG Cailin;ZHANG Huimin(College of Pipeline and Civil Engineering in China University of Petroleum(East China),Qingdao 266580,China;Shandong Key Laboratory of Oil-Gas Storage and Transportation Safety,Qingdao 266580,China;PetroChina Coalbed Methane Company Limited Shanxi Branch,Taiyuan 030000,China)

机构地区：[1]中国石油大学(华东)储运与建筑工程学院,山东青岛266580 [2]山东省油气储运安全重点实验室,山东青岛266580 [3]中石油煤层气有限责任公司山西分公司,山西太原030000

出　　处：《中国石油大学学报（自然科学版）》2024年第5期160-167,共8页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家重点研发计划(2021YFB4001601)。

摘　　要：氢气大规模输送是实现中国“双碳”战略目标的重要环节,但将氢气掺入现有天然气管网可能引发管道氢脆,焊缝处存在严重的应力集中,更易导致氢富集进而可能导致管道失效。采用ABAQUS软件建立含夹杂的20号钢环焊缝二维模型,利用热力耦合方法分析焊接温度场及残余应力场;在考虑接头组织不均匀性和焊缝处存在残余应力的基础上进行氢扩散仿真模拟,分析夹杂分布、取向和形状对焊缝中氢扩散特性的影响规律。结果表明:当夹杂平行于氢扩散方向时,夹杂边界周围应力集中的区域易产生氢偏聚;填充层中夹杂-焊缝金属界面局部氢浓度最高,约为根焊层的2.45倍;当夹杂垂直于氢扩散方向时,残余压应力不利于堆叠夹杂的氢捕获;与平行于氢扩散方向夹杂相比,填充层夹杂内最高氢浓度降幅达到了48%;当填充层存在球状夹杂时,氢并没有在夹杂-焊缝金属界面聚集,而是扩散到了接头附近的母材区域,增大了管材失效风险。Large-scale transportation of hydrogen is an essential component to achieve the strategic goal of carbon peak and carbon neutrality.However,blending hydrogen into the present natural gas pipeline network may cause hydrogen embrittlement of pipelines.Serious stress concentration at the weld joint may happen,which is prone to hydrogen enrichment and subsequent potential pipe failure.The two-dimensional model of steel 20 girth weld with inclusions was built by using the software of ABAQUS.The thermal-mechanical coupling method was used to analyze the welding temperature and residual stress fields.Subsequently,hydrogen diffusion simulations were conducted considering the microstructure heterogeneity of the welded joint and the presence of residual stresses at the weld seam,and the effect of the inclusion s distribution,orientation and0x0E䥺Symbol`@@0x0F shape on the hydrogen diffusion behavior in the weld seam was analyzed.The results show that,when the inclusions are parallel to the hydrogen diffusion orientation,the region of stress concentration around the inclusion s boundary is prone to hydrogen partial gathering.The maximum local hydrogen concentration at the inclusions-weld interface in the filler layer is about 2.45 times that of the root weld layer.When the inclusions are perpendicular to the hydrogen diffusion direction,the residual compressive stress is not favorable for hydrogen trapping in the stacked inclusions.The maximum hydrogen concentration in the filled layer was reduced by almost 48%compared to the inclusions parallel to the hydrogen diffusion direction.In addition,when spherical inclusions exist in the filler layer,there is no hydrogen enrichment at the inclusions-weld interface,and hydrogen diffuses into the pipeline steel area near the joint,increasing the risk of pipe failure.

关 键 词：夹杂物 环焊缝 残余应力 氢扩散 氢富集 

分 类 号：TE88[石油与天然气工程—油气储运工程]