PSI - Issue 59

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000

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Procedia Structural Integrity 59 (2024) 125–130

© 2024 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 DMDP 2023 Organizers © 2024 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 DMDP 2023 Organizers Abstract Transportation of gaseous hydrogen or a mixture of hydrogen with natural gas by the existing natural gas steel pipeline increases a failure risk due to hydrogen absorption and, consequently, hydrogen-induced degradation. Therefore, the study of the sensitivity of pipe steels to hydrogen embrittlement, and the assessment of crack growth resistance, in particular, fracture toughness, is an important issue for their fitness-for-service. In this work, the effect of hydrogen on the fracture toughness of a low-alloyed pipeline steel was investigated in the case of hydrogen pre-charging, and then fracture toughness tests were carried out in air at the different displacement rates. The fracture toughness of pipe steels was determined by the J -integral method due to their high plasticity. Single-edge notched beam specimens were subjected to three-point bending. J -integral parameter, J 0,2 index, corresponding to the J -integral value for a crack growth of 0.2 mm, was measured. Under the hydrogen pre-charging, the fracture toughness J 0,2 of the studied steel is decreased, especially under a slow displacement rate. The higher sensitivity of the J 0,2 index to hydrogen embrittlement of the steel compared to the parameter J 0 , indicating crack initiation was revealed. © 2024 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 DMDP 2023 Organizers VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Techniques for investigation of hydrogen influence on fracture toughness and embrittlement of pipeline steels Hryhoriy Nykyforchyn*, Oleksandr Tsyrulnyk, Oleh Venhryniuk, Olha Zvirko Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, 5, Naukova St., 79060 Lviv, Ukraine Abstract Transportation of gaseous hydrogen or a mixture of hydrogen with natural gas by the existing natural gas steel pipeline increases a failure risk due to hydrogen absorption and, consequently, hydrogen-induced degradation. Therefore, the study of the sensitivity of pipe steels to hydrogen embrittlement, and the assessment of crack growth resistance, in particular, fracture toughness, is an important issue for their fitness-for-service. In this work, the effect of hydrogen on the fracture toughness of a low-alloyed pipeline steel was investigated in the case of hydrogen pre-charging, and then fracture toughness tests were carried out in air at the different displacement rates. The fracture toughness of pipe steels was determined by the J -integral method due to their high plasticity. Single-edge notched beam specimens were subjected to three-point bending. J -integral parameter, J 0,2 index, corresponding to the J -integral value for a crack growth of 0.2 mm, was measured. Under the hydrogen pre-charging, the fracture toughness J 0,2 of the studied steel is decreased, especially under a slow displacement rate. The higher sensitivity of the J 0,2 index to hydrogen embrittlement of the steel compared to the parameter J 0 , indicating crack initiation was revealed. VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Techniques for investigation of hydrogen influence on fracture toughness and embrittlement of pipeline steels Hryhoriy Nykyforchyn*, Oleksandr Tsyrulnyk, Oleh Venhryniuk, Olha Zvirko Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, 5, Naukova St., 79060 Lviv, Ukraine

Keywords: pipe steel, fracture toughness, J -integral method, hydrogen embrittlement, slow displacement rate Keywords: pipe steel, fracture toughness, J -integral method, hydrogen embrittlement, slow displacement rate

* Corresponding author. Tel.: +380 322 294213; fax: +380 322 649427. E-mail address: hnykyforchyn@gmail.com * Corresponding author. Tel.: +380 322 294213; fax: +380 322 649427. E-mail address: hnykyforchyn@gmail.com

2452-3216 © 2024 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 DMDP 2023 Organizers 2452-3216 © 2024 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 DMDP 2023 Organizers

2452-3216 © 2024 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 DMDP 2023 Organizers 10.1016/j.prostr.2024.04.019