α-Fe和γ-Fe中氢扩散行为的第一性原理计算  

First-principles calculations on the diffusion behaviors of hydrogen atom inα-Fe andγ-Fe

作　　者：张凤春 张小山[1] 李春福 文平[2] 罗强[3] ZHANG Feng-Chun;ZHANG Xiao-Shan;LI Chun-Fu;WEN Ping;LUO Qiang(School of Materials Engineering, Chengdu Technological University, Chengdu 611730, China;School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China;School of Science, Southwest Petroleum University, Chengdu 610500, China)

机构地区：[1]成都工业学院材料工程学院,成都611730 [2]西南石油大学材料科学与工程学院,成都610500 [3]西南石油大学理学院,成都610500

出　　处：《原子与分子物理学报》2020年第3期397-402,共6页Journal of Atomic and Molecular Physics

基　　金：四川省教育厅项目(17ZB0034)。

摘　　要：采用基于密度泛函理论的第一性原理方法,研究了α-Fe和γ-Fe中氢扩散行为,建立了两相的H原子扩散系数与温度的关系式,对比了H原子在两相中扩散的难易程度,并结合2205双相不锈钢的氢致开裂试验对计算结果进行了实验验证.研究结果表明:H原子在α-Fe中所需扩散激活能较γ-Fe低,其容易在α-Fe的缺陷处聚集,并最终造成氢致开裂等严重后果;而2205双相不锈钢的HIC实验表明,裂纹在铁素体相中表现为穿晶型开裂,并且在传播过程中由于受到奥氏体相的阻碍,裂纹沿两相界面发展,表现出混合型开裂方式;综上所述,铁素体相更容易产生氢致裂纹,这进一步证实了本文计算结果的可靠性.The diffusion behaviors of hydrogen atom inα-Fe andγ-Fe are studied by means of first principles method based on the density functional theory(DFT);The relationships between the diffusion coefficient of hydrogen atom and temperature inα-Fe andγ-Fe are established;The difficulties of hydrogen atom diffusing inα-Fe andγ-Fe are compared;And the theoretical calculations are verified by combining with the hydrogen induced cracking test of 2205 duplex stainless steel.The results show that the diffusion activation energy of hydrogen atom inα-Fe is lower than that inγ-Fe,indicating that the hydrogen atom is easily gathered in the defects ofα-Fe,and eventually results in the hydrogen induced cracking and other serious consequences.And the hydrogen induced cracking experimental results of 2205 duplex stainless steel prove that the crack in ferrite phase shows transgranular cracking,and in the process of transmission,hampered by austenite phase,then develop along the two phase interface,indicates mixed cracking way;As summarized in the review,the ferrite phase is more easily to generate hydrogen induced cracks,further confirms the reliability of the calculation results in this paper.

关 键 词：氢扩散 扩散激活能 第一性原理 氢致开裂 

分 类 号：O469[理学—凝聚态物理]