L245管线钢环焊缝不同应力集中系数缺口氢脆敏感性实验  

Experiment on hydrogen embrittlement sensitivity of L245 pipeline steel girth weld with different stress concentration factors

作　　者：宋卫臣[1] 胡松岩 程光旭[2] 汪兵[3] 胡海军[2] 涂圣文 SONG Weichen;HU Songyan;CHENG Guangxu;WANG Bing;HU Haijun;TU Shengwen(Sinopec Petroleum Engineering Corporation,Dongying 257000,China;School of Chemical Engineering and Technology,Xi′an Jiaotong University,Xi′an 710049,China;Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]中石化石油工程设计有限公司,山东东营257000 [2]西安交通大学化学工程与技术学院,陕西西安710049 [3]钢铁研究总院有限公司,北京100081

出　　处：《冶金分析》2024年第9期91-98,共8页Metallurgical Analysis

摘　　要：管道环焊缝的焊接会产生显微组织和机械性能的变化,往往不可避免地产生焊接缺欠。氢原子在焊接缺欠形成的应力集中区域聚集,会增加材料氢脆的敏感性。本文选用L245输氢管线钢,将环焊缝金属缺口拉伸试样,分别在6.3 MPa氢气和氮气环境下开展慢应变速率拉伸试验,研究不同应力集中系数的焊缝金属氢脆敏感性变化规律,并采用扫描电子显微镜(SEM)对断口进行微观表征分析。研究表明,焊缝金属的氢脆敏感性随着应力集中系数的增大并非单调增大,在应力集中系数大到某个值时,氢脆敏感性反而下降,从而提出基于本试验的转折应力集中系数Ktt的概念。定义了基于本试验的临界应力集中系数Kct,对于输氢管道铺设施工中建立焊接缺欠的工程研判标准有重要作用。The welding of pipe girth weld will cause the change of microstructure and mechanical property,and it usually inevitably leads to welding imperfection.Hydrogen atoms can be aggregated in the region of stress concentration formed by welding imperfection,which will enhance the hydrogen embrittlement sensitivity of material.In this study,L245 hydrogen transport pipeline steel was selected.The girth weld notch tension samples were tested at slow strain rate under 6.3 MPa hydrogen and nitrogen environments.The hydrogen embrittlement sensitivity change law of weld metal with different stress concentration factors was investigated.Moreover,the microstructure of fracture was characterized and analyzed by scanning electron microscope(SEM).The results showed that the hydrogen embrittlement sensitivity of weld metal did not monotonically increase with the increase of stress concentration factor.When the stress concentration factor increased to a certain value,the hydrogen embrittlement sensitivity decreased instead.The concept of transition stress concentration factor(Ktt)based on the tests was proposed.The critical stress concentration factor(Kct)was defined,which was important for the establishment of engineering judgment standard of welding imperfection in the laying construction of hydrogen transport pipes.

关 键 词：L245管线钢 输氢管道 环焊缝 应力集中 氢脆敏感性 解理断裂 

分 类 号：TE832[石油与天然气工程—油气储运工程] TF76[冶金工程—钢铁冶金]