PSI - Issue 13

Zahreddine Hafsi et al. / Procedia Structural Integrity 13 (2018) 210–217 Hafsi et al. / Structural Integrity Procedia 00 (2018) 000–000

217

8

have its proper diffusion coefficient prior to permeate into the lattice structure of steel. However, one needs to deeply analyze hydrogen diffusion through coated steel materials to judge about the efficiency of coating layer in facing hydrogen embrittlement phenomenon. 4. Conclusion Diffusion of hydrogen gas through steel lattice structure has been investigated in the outlet of a relatively long gas pipeline. The mass transfer phenomenon limited in the study to diffusion with constant diffusion coefficient is enhanced by transient pressure evolution of the gas flow. Thus, both models of gas flow in a pipeline and non steady diffusion of hydrogen in steel has been coupled to follow up the permeation depth of hydrogen trough the pipe wall and hence to prevent gas leakage. The steel grade materials API X52 and API X80 has been chosen as case studies as they are commonly used for natural gas pipeline and the overall aim of this study is to discuss the approach of using existing gas networks to transport hydrogen even pure or as a mixture with natural gas. The presented study demonstrated that this replacement of the transported gas has to be preceded by feasibility studies taking in account both aspect of fatigue of material and pipeline failure due to overpressure and also due to hydrogen embrittlement. Besides, through the presented work, it was proven that opting for nitrided steel or using higher grade steel pipes improves safe working conditions. One needs to go further by studying coating effect on hydrogen embrittlement and also the effect of a non-constant diffusion coefficient may be investigated. References Barrera, O., Tarleton, E., Tang, H.W., Cocks, A.C.F., 2016. Modelling the coupling between hydrogen diffusion and the mechanical behaviour of metals. Computational Materials Science 122:219–228. Bhadeshiaa, H.K., 2016. Prevention of Hydrogen Embrittlement in Steels, ISIJ International 56:24-36. Brass, A.M., Chene, J.,2008. Influence of hydrogen transport and trapping in ferritic steels with electrochemical permeation technic. Env. Induced Crac. of Mat. 215-225. Cendales, E.D., Orjuela, F.A., Chamarrav, O., 2016. Computational modeling of the mechanism of hydrogen embrittlement (HE) and stress corrosion cracking (SCC) in metals. Journal of Physics: Conference Series 687 (2016) 012067 doi:10.1088/1742-6596/687/1/012067. Chatzidouros, E.V., Traidia, A., Devarapalli, R.S., Pantelis, D.I., Steriotis, T.A., Jouiad, M., 2018. Effect of hydrogen on fracture toughness properties of a pipeline steel under simulated sour service conditions. International Journal of Hydrogen Energy. DOI:10.1016/j.ijhydene.2018.01.186 Cisneros, M.M., Lopez, H.F., Salas, N., Valdés, J.V., Cisneros, M.A., Figueroa, U., 2003. Hydrogen Permeability in a Plasma Nitrided API X52 Steel. Materials Science Forum 442:85-90. Dayal, R.K., Parvathavarthini,N., 2003. Hydrogen embrittlement in power plant steels. Sadhana 28:431-451. Elaoud, S., Hadj Taieb, E., 2011. Analysis of resonance phenomenon of hydrogen-natural gas mixtures flows in pipelines. Structural integrity and life 11(2):75-81. Frederiksen, J.M, Mejlbro, J., Nilsson, L.O., 2008. Fick's 2 nd law - Complete solutions for chloride ingress into concrete. Report TVBM-3146, Lund institute of technology, division of building materials, 2008 Grabke, H.J., Riecke, E., 2000. Absorption and Diffusion of Hydrogen in Steels. Materiali In Tehnologije 34(6):331-342. Norazlina, S., Norsarahaida, A., 2015. Analysis of Water Hammer with Different Closing Valve Laws on Transient Flow of Hydrogen-Natural Gas Mixture. Abstract and Applied Analysis. http://dx.doi.org/10.1155/2015/510675 Peng, X. Y., Cheng Y. F., 2014. A comparison of hydrogen permeation and the resulting corrosion enhancement of X65 and X80 pipeline steels. Canadian Metallurgical Quarterly 53(1):107-111. Steward, S.A., 1983. Review of Hydrogen Isotope Permeability Through Materials. United States: N. p., 1983. Web. doi:10.2172/5277693. Tabkhi, F., Azzaro, P.C., Pibouleau, L., Domenech, S.A., 2008. Mathematical framework for modelling and evaluating natural gas pipeline networks under hydrogen injection. International Journal of Hydrogen Energy 33:6222–6231.