利用Abaqus有限元软件建立了氢在含不同奥氏体相体积分数(φγ)双相不锈钢中的二维扩散有限元模型,分析了φγ对氢在双相不锈钢中扩散分布的影响,计算了氢在含不同φγ的模型中的表观扩散系数(Dapp),建立了Dapp与φγ的关系式.结果表明:氢在双相不锈钢中的Dapp随着φγ的增加而降低,并且ln Dapp与φγ之间呈现出线性变化关系;将φγ=44.3%, 50.0%, 57.3% 的3种模型中的奥氏体相沿扩散深度方向延长,以分析氢沿着双相不锈钢横向和纵向组织中的扩散差异.结果表明,氢在纵向组织中的扩散速度更小,氢脆敏感性更弱.
Duplex stainless steels (DSS) are subjected to a deleterious effect known as hydrogen embrittlement. Due to the difference of the ratio of various alloying elements and the influence of processing technology, the volume fraction of austenite phase (φγ) will be changed. Hydrogen diffusion models with different φγ were established based on transient finite element mass diffusion in program—Abaqus. In addition, the discrepancies of hydrogen diffusion in both transverse and longitudinal microstructure were implemented. After the simulation analysis, the apparent diffusion coefficients (Dapp) of the models were calculated. The results show that Dapp decreased with the increase of φγ, and there is a linear relationship between ln Dapp and φγ; the values of hydrogen diffusion coefficient are greater when the elongated austenite is orientated parallel with the direction of hydrogen flux, i.e. the transverse samples are more susceptible to hydrogen embrittlement than longitudinal samples.
[1]VAOVP, SOJKA J. Hydrogen embrittlement of duplex steel tested using slow strain rate test[J]. Metalurgija, 2014, 53(2): 163-166.
[2]SRLVERSTEIN R, DAN E, GLAM B, et al. Influence of hydrogen on microstructure and dynamic strength of lean duplex stainless steel[J]. Journal of Materials Science, 2014, 49(11): 4025-4031.
[3]SILVA B R S D, SALVIO F, SANTOS D S D. Hydrogen induced stress cracking in UNS S32750 super duplex stainless steel tube weld joint[J]. International Journal of Hydrogen Energy, 2015, 40(47): 17091-17101.
[4]SILVERSTEIN R, ELIEZER D. Hydrogen trapping mechanism of different duplex stainless steels alloys[J]. Journal of Alloys and Compounds, 2015, 644: 280-286.
[5]褚武扬. 氢脆和应力腐蚀[M]. 北京: 科学出版社, 2013.
CHU Wuyang. Hydrogen embrittlement and stress corrosion cracking[M]. Beijing: Science Press, 2013.
[6]TURNBULL A, BEYLEGAARD E L, HUTCHINGS R B. Hydrogen transport in SAF 2205 and SAF 2507 duplex stainless steels[C]∥Hydrogen Transport and Cracking in Metals. London: Institute of Materials, 1995, 605: 268-279.
[7]OWCZAREK E, ZAKROCZYMSKI T. Hydrogen transport in a duplex stainless steel[J]. Acta Materialia, 2000, 48(12): 3059-3070.
[8]ZAKROCZYMSKI T, OWCZAREK E. Electrochemical investigation of hydrogen absorption in a duplex stainless steel[J]. Acta Materialia, 2002, 50(10): 2701-2713.
[9]MENTE T, BOELLINGHAUS T. Mesoscale modeling of hydrogen-assisted cracking in duplex stainless steels[J]. Welding in the World, 2014, 58(2): 205-216.
[10]OLDEN V, SAAI A, JOHNSEN R, et al. FE simulation of hydrogen diffusion in duplex stainless steel[J]. International Journal of Hydrogen Energy, 2014, 39(2): 1156-1163.
[11]WAGENBLAST H, WRIEDT H A. Dilation of alpha iron by dissolved hydrogen at 450℃ to 800℃[J]. Metallurgical and Materials Transactions B, 1971, 2(5): 1393-1397.
[12]MINE Y, NARAZAKI C, MURAKAMI K, et al. Hydrogen transport in solution-treated and pre-strained austenitic stainless steels and its role in hydrogen-enhanced fatigue crack growth[J]. International Journal of Hydrogen Energy, 2009, 34(2): 1097-1107.
[13]OLDEN V, THAULOW C, JOHNSEN R. Modelling of hydrogen diffusion and hydrogen induced cracking in supermartensitic and duplex stainless steels[J]. Materials & Design, 2008, 29(10): 1934-1948.
[14]CHOU S L, TSAI W T. Effect of grain size on the hydrogen-assisted cracking in duplex stainless steels[J]. Materials Science and Engineering A, 1999, 270(2): 219-224.
[15]何建宏, 唐祥云, 陈南平. 氢在(α+γ)双相不锈钢中的扩散[J]. 金属学报, 1989, 25(1): 37-41.
HE Jianhong, TANG Xiangyun, CHEN Nanping. Diffusion of hydrogen in (α+γ) duplex stainless steel[J]. Acta Metallurgica Sinica, 1989, 25(1): 37-41.
[16]GESNOUIN C, HAZARABEDIAN A, BRUZZONI P, et al. Effect of post-weld heat treatment on the microstructure and hydrogen permeation of 13CrNiMo steels[J]. Corrosion Science, 2004, 46(7): 1633-1647.
[17]SHARRFEDDIN A, MUSA S M, ELSHAWESH F M. Role of structural orientation on the susceptibility of 2205 duplex stainless steel to hydrogen embrittlement[C]∥International Congress on Advances in Applied Physics and Materials. New York, USA: Ame-rican Institute of Physics, 2012, 1476: 199-203.