Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel  

作　　者：Tao-long Xu Si-han Guo Gong-zhen He Hao-yu Han 

机构地区：[1]Petroleum Engineering School,Southwest Petroleum University,Chengdu,610500,Sichuan,China [2]Sichuan East Gas Transmission Sales Center of Sinopec Natural Gas Branch,Wuhan,430074,Hubei,China

出　　处：《Journal of Iron and Steel Research International》2024年第2期488-500,共13页

基　　金：Financial support from the Scientific and Technological Innovation Team for the Safety of Petroleum Tubular Goods at the Southwest Petroleum University(Grant No.2018CXTD01);“The Young Scholars”Development Fund of the Southwest Petroleum University of China is appreciated.

摘　　要：Hydrogen embrittlement of pipelines depends on the hydrogen-induced cracking behavior of the pipeline steel microstructure.Based on molecular dynamics analysis,the ferrite–cementite(α-Fe/Fe3C)lamellar atomic structure with the Bagaryatskii orientation relationship was established,and stepwise relaxation of the conjugate gradient energy minimization and constant-temperature and constant-pressure relaxation were performed under NPT(the isothermal–isobaric)conditions.The mechanical property curves of theα-Fe/Fe3C models were obtained under different cementite terminal plane structures,and the evolution of the atomic structure was analyzed in detail.In addition,the influence of different hydrogen concentrations,different temperatures,different strain rates,changes in voids,and different micro-degrees of freedom on the deformation and failure mechanism of the model was investigated,aiming to provide a reliable way to explore the micro-mechanism of macro-cracking behavior of pipeline steel.

关 键 词：Ferrite-cementite lamellar structure Pipeline steel Failure mechanism Crack propagation Molecular dynamics 

分 类 号：TG142[一般工业技术—材料科学与工程]