Thesis supervisor: Marcell Gyula Gáspár
Location of studies (in Hungarian): Institute of Material Science and Technology Abbreviation of location of studies: ATI
Description of the research topic:
Nowadays, with growing concern over environmental issues and carbon emissions due to the large consumption of fossil fuel, hydrogen is being foreseen as an alternative clean energy source for various applications ranging from power plants to automotive applications. There were several grades of pipeline already available on the market for natural gas pipeline transport, but transporting pressurised hydrogen is difficult due to hydrogen atom diffusion into the lattice of pipeline steel. So, the hydrogen transport compatibility of the material is very important, and nowadays, industries and research organizations are working on the development of the best suitable materials for hydrogen transport. So, in order to assess the technical feasibility of the transport of hydrogen through a pipeline, it is necessary to study the effect of welding on the joint properties in terms of hydrogen susceptibility. Certain microstructural changes may cause hydrogen-induced cracking in the joints. The heat affected zone is the major concern since the higher peak temperature during the welding affects the microstructure and results in the grain growth. The other factors include the weld defects, joint strength, residual stress, hardness behaviour, etc. Also, during the fast cooling, microstructural transformation to martensite and bainite affects the toughness and finally leads to hydrogen embrittlement. With regard to welding processes, plasma arc welding and GTA welding process will come to the fore, and the application of these processes should be analysed.
The research should focus on:
• The development and application trends of pipeline steels and their suitability for welding should be analysed;
• Optical and electron microscopic techniques should be used to investigate the non-equilibrium changes of pipeline steels due to various welding thermal cycles with industrial realities;
• The temperature field formed during welding and the consequent metallurgical changes must be examined by finite element modelling (FEM), the most favourable weld structure must be determined on the basis of the obtained results;
• The critical HAZ subzones of the welded joint must be reproduced by Gleeble 3500 physical simulator; and the microstructure and properties should be analyzed to understand the hydrogen embrittlement;
• The relationship between the base material, HAZ and weld microstructure and mechanical properties should be investigated considering autogenous welds and also the application of filler metals;
• The possibilities of repair welding should be investigated under hydrogen atmosphere.
Research conditions: the equipment for welding (Plasma arc welding, Gas tungsten arc welding), physical simulator (Gleeble 3500) and the materials investigations (MTS electro-hydraulic universal material tester, hardness testers, instrumented impact tester, microscopes), residual stress (XRD) etc.
Industrial background: the Institute of Materials Science and Technology provide a wide cooperation network in the industrial area (e.g., MOL Group, FGSZ ZRt.).
Part-time education abroad: the actuality and importance of the research work offer the possibility of part time research abroad (University of Oulu, Finland; Slovak University of Technology in Bratislava, Slovakia; Silesian University of Technology, Poland).
Additional expectations:
• Language: an adequate knowledge of the English language is essential for the study of the literature
• Preliminary studies:
good or excellent grade in the engineering field (MSc),
professional knowledge in the field of welding, material science and material technologies,
experience in the use of (CAD, CAM, FEM) software is advantageous.
Recommended literature to the research work:
• Gáspár Marcell, Sisodia Raghawendra. Physical simulation based HAZ characterization of different pipeline steel grades, In: Manabu, Tanaka (ed.) Proceedings of the IIW2022 - International Conference on Welding and Joining : Innovative Welding and Joining Technologies to achieve Carbon Neutrality and promote Sustainable Development, Tokió, Japán : Japan Institute of Welding (2022) 594 p. pp. 264-267., 4 p.
• Gáspár Marcell. Effect of Welding Heat Input on Simulated HAZ Areas in S960QL High Strength Steel, METALS 9:11 Paper: 1226 (2019) https://doi.org/10.3390/met9111226
• Junghoon Lee, Myeonghyun Kim, Yeongdo Park, Cheolho Park, Cheolhee Kim, Namhyun Kang. Hydrogen-Induced Cracking of Laser Beam and Gas Metal Arc Welds on API X65 Steel. Korean Journal of Metals and Materials 2019; 57(8): 491-498. http://dx.doi.org/10.3365/KJMM.2019.57.8.491
• Bhadeshia HKDH. Lower bainite transformation and the significance of carbide precipitation. Acta Metall 1980; 28:1103e14. https://doi.org/10.1016/0001-6160(80)90093-0
• Bhadeshia HKDH, Edmonds DV. Mechanism of bainite formation in steels. Acta Metall 1980; 28:1265e73. https://doi.org/10.1016/0001-6160(80)90082-6
• Hirth JP. Effects of hydrogen on the properties of iron and steel. Metall Trans A 1980;11:861e90. https://doi.org/10.1007/BF02654700
• Hardie D, Charles EA, Lopez AH. Hydrogen embrittlement of high strength pipeline steels. Corros Sci 2006;48:4378e85. https://doi.org/10.1016/j.corsci.2006.02.011.
• Drexler ES, Slifka AJ, Amaro RL, Sowards JW, Connolly MJ, Martin ML, Lauria DS. Fatigue Testing of Pipeline Welds and Heat-Affected Zones in Pressurized Hydrogen Gas 2019; J Res Natl Inst Stan 124:124008. https://doi.org/10.6028/jres.124.008
• Joseph A. Ronevich, Eun Ju Song, Brian P. Somerday, Christopher W. San Marchi, Hydrogen-assisted fracture resistance of pipeline welds in gaseous hydrogen, International Journal of Hydrogen Energy, Volume 46, Issue 10, 2021, Pages 7601-7614, https://doi.org/10.1016/j.ijhydene.2020.11.239
• Yinghao Sun, Y. Frank Cheng. Hydrogen permeation and distribution at a high-strength X80 steel weld under stressing conditions and the implication on pipeline failure, International Journal of Hydrogen Energy, Volume 46, Issue 44, 2021, Pages 23100-23112, https://doi.org/10.1016/j.ijhydene.2021.04.115
• Anette Brocks Hagen Antonio Alvaro. Hydrogen Influence on Mechanical Properties in Pipeline Steel.2020 Materials Integrity and Welding, SINTEF Industry
Number of students who can be accepted: 1
Deadline for application: 2023-06-30
2024. IV. 17. ODT ülés Az ODT következő ülésére 2024. június 14-én, pénteken 10.00 órakor kerül sor a Semmelweis Egyetem Szenátusi termében (Bp. Üllői út 26. I. emelet).
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