PSI - Issue 68

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 68 (2025) 1105–1114

European Conference on Fracture 2024 The Effect of Hydrogen Gas on Tensile and Fatigue Properties of High Strength Carbon Steels Eduard Navalles 1,3* , Nuria Fuertes 1 , Esa Virolainen 2 , Caroline Klar Jaans 2 , Pia Åkerfeldt 3 , Marta-Lena Antti 3 , Birhan Sefer 1 1 Swerim AB, Box 7047, 164 07 Kista, Sweden 2 SSAB Europe 3 Luleå University of Technology, Department of Engineering and Mathematics, Division of Materials Science 97187 Luleå, Sweden Abstract This study investigates the impact of hydrogen gas on the tensile and low cycle fatigue (LCF) properties of two high strength steels by means of the hollow specimen method. The steels studied have ultimate tensile strengths in the range of 530 to 650 MPa, and ferritic-pearlitic and bainitic microstructures, respectively. The behaviour of these steels was evaluated in a pressurized environment containing either inert gas (Ar) or hydrogen (H 2 ) at room temperature and a pressure of 200 bar. The findings of this work indicate that hydrogen has a detrimental effect on the ductility and reduction in area, while the other tensile properties remain unaffected for both steels. Hydrogen uptake due to the interaction between H 2 and steel during mechanical testing was measured. The fractographic analysis revealed presence of brittle fracture and embrittlement despite that the tensile properties of the steels were not affected. In contrast, the fatigue life of both steels was severely affected by H 2 compared to Ar environment when tested at high strain amplitudes. The fractographic inspection of the LCF tested specimens indicated differences in crack propagation behaviour between Ar and H 2 environment. Specimens tested in H 2 indicated faster crack growth and widely spread striations. Finally, this work concludes that the bainitic steel exhibits slightly better mechanical performance than the ferritic-pearlitic steel in pressurized hydrogen gas for the respective testing conditions. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers European Conference on Fracture 2024 The Effect of Hydrogen Gas on Tensile and Fatigue Properties of High Strength Carbon Steels Eduard Navalles 1,3* , Nuria Fuertes 1 , Esa Virolainen 2 , Caroline Klar Jaans 2 , Pia Åkerfeldt 3 , Marta-Lena Antti 3 , Birhan Sefer 1 1 Swerim AB, Box 7047, 164 07 Kista, Sweden 2 SSAB Europe 3 Luleå University of Technology, Department of Engineering and Mathematics, Division of Materials Science 97187 Luleå, Sweden Abstract This study investigates the impact of hydrogen gas on the tensile and low cycle fatigue (LCF) properties of two high strength steels by means of the hollow specimen method. The steels studied have ultimate tensile strengths in the range of 530 to 650 MPa, and ferritic-pearlitic and bainitic microstructures, respectively. The behaviour of these steels was evaluated in a pressurized environment containing either inert gas (Ar) or hydrogen (H 2 ) at room temperature and a pressure of 200 bar. The findings of this work indicate that hydrogen has a detrimental effect on the ductility and reduction in area, while the other tensile properties remain unaffected for both steels. Hydrogen uptake due to the interaction between H 2 and steel during mechanical testing was measured. The fractographic analysis revealed presence of brittle fracture and embrittlement despite that the tensile properties of the steels were not affected. In contrast, the fatigue life of both steels was severely affected by H 2 compared to Ar environment when tested at high strain amplitudes. The fractographic inspection of the LCF tested specimens indicated differences in crack propagation behaviour between Ar and H 2 environment. Specimens tested in H 2 indicated faster crack growth and widely spread striations. Finally, this work concludes that the bainitic steel exhibits slightly better mechanical performance than the ferritic-pearlitic steel in pressurized hydrogen gas for the respective testing conditions. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers Keywords : Hydrogen embrittlement, Hydrogen gas, Pressure vessels, Carbon steels, Hollow specimen, LCF, SSRT, TMDS, Fractography. Keywords : Hydrogen embrittlement, Hydrogen gas, Pressure vessels, Carbon steels, Hollow specimen, LCF, SSRT, TMDS, Fractography.

* Corresponding author. Tel.: +46 (0)76 133 15 08. E-mail address: eduard.navalles@swerim.se * Corresponding author. Tel.: +46 (0)76 133 15 08. E-mail address: eduard.navalles@swerim.se

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers 10.1016/j.prostr.2025.06.176 2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers 2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers