氢环境下X52管线钢的抗氢性能  

Hydrogen Resistance of X52 Pipeline Steel Under Hydrogen Environment

作　　者：白光乾 王秋岩 邓海全 李冬林 李云[1] BAI Guangqian;WANG Qiuyan;DENG Haiquan;LI Donglin;LI Yun(School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Sinopec Petroleum Engineering Zhongyuan Corporation,Puyang 457001,China)

机构地区：[1]西安交通大学化学工程与技术学院,西安710049 [2]中石化中原石油工程设计有限公司,濮阳457001

出　　处：《材料导报》2020年第22期22130-22135,共6页Materials Reports

基　　金：浙江省重点研发计划(2020C01119)。

摘　　要：天然气混氢(HCNG)作为一种新型输氢技术,对于实现氢气的大规模管网运输具有重要意义。但氢的存在会导致管道力学性能劣化,对管网的安全使用产生威胁。本工作以X52管线钢为研究对象,通过动态充氢慢拉伸试验研究了充氢对X52管线钢拉伸性能的影响;通过疲劳裂纹扩展试验研究了电解氢环境对X52管线钢裂纹扩展速率的影响。此外,还借助SEM对拉伸和疲劳试样的断口形貌进行观察,进而分析材料氢脆断裂机理。结果表明:(1)电化学充氢会改变材料的力学性能,随着充氢电流密度增大,材料的强度略微提高,但塑性显著下降;(2)拉伸试样断面微观结构的变化表明随着充氢电流密度增大,材料的断裂模式由韧窝韧性断裂过渡到准解理脆性断裂;(3)电解氢环境会加快X52管线钢的裂纹扩展速率,微观断口表明氢脆机制主导了裂纹扩展过程。As a new technology for hydrogen transporting,hydrogen and compressed nature gas(HCNG)has significance on the realization of large-scale hydrogen transportationby pipeline network.However,the presence of hydrogen will lead to the mechanical properties degradation of pipeline metal,which seriously threatens the safe use of pipeline network.X52 pipeline steel was chosen as the research object.The influence of hydrogen charging current density on the tensile property of X52 was studied by simultaneous cathodic charging and slow straining rate test.The influence of electrolytic hydrogen environment on crack growth rate of X52 was studied through fatigue crack growth test.In addition,the fracture morphology of tensile and fatigue specimens was observed by means of SEM to analyze the mechanism of X52 hydrogen embrittlement fracture.Test results show that electrochemical hydrogen charging has effect on mechanical properties of X52.As charging current density elevates,the strength of materials enhances slightly but its plasticity decreases significantly.Changes in the microstructure of the tensile specimen section indicated that the fracture mode of material transforms from dimple ductile fracture to quasi-dissociative brittle fracture with elevated hydrogen charging current density.Electrolytic hydrogen environment will accelerate the crack growth rate of X52.Micro fractures indicate that hydrogen embrittlement mechanism dominates the crack propagation process.

关 键 词：管线钢 电化学充氢 慢应变速率拉伸 疲劳裂纹扩展 氢脆 

分 类 号：TG172[金属学及工艺—金属表面处理]