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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ScienceDirect

Procedia Structural Integrity 59 (2024) 190–197

© 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 The paper analyses hydrogen diffusion taking into account the stress field for a steel pipe with a crack on the inner surface under internal pressure. On the inner surface of the pipe, the hydrogen concentration, calculated using the volatility of hydrogen molecules, was used as a boundary condition for the hydrogen diffusion equation. The finite element method was used for both hydrogen diffusion and stress analysis. We obtained the hydrogen concentration around the crack tip by varying the magnitude of the internal pressure and the shape of the crack, and investigated the relationship between the maximum hydrogen concentration and the internal hydrogen pressure. A satisfactory correlation between the maximum hydrogen concentration and the pressure was found. © 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 Hydrogen diffusion in metals is determined not only by the hydrogen concentration gradient, but also by the hydrogen flow, which is determined by the hydrostatic stress gradient. Such hydrogen diffusion is a multifactorial problem involving hydrogen diffusion and the stress field. The paper analyses hydrogen diffusion taking into account the stress field for a steel pipe with a crack on the inner surface under internal pressure. On the inner surface of the pipe, the hydrogen concentration, calculated using the volatility of hydrogen molecules, was used as a boundary condition for the hydrogen diffusion equation. The finite element method was used for both hydrogen diffusion and stress analysis. We obtained the hydrogen concentration around the crack tip by varying the magnitude of the internal pressure and the shape of the crack, and investigated the relationship between the maximum hydrogen concentration and the internal hydrogen pressure. A satisfactory correlation between the maximum hydrogen concentration and the pressure was found. Hydrogen diffusion in metals is determined not only by the hydrogen concentration gradient, but also by the hydrogen flow, which is determined by the hydrostatic stress gradient. Such hydrogen diffusion is a multifactorial problem involving hydrogen diffusion and the stress field. Keywords: crack-like defects; fatigue crack growth rate; stress intensity factor; hydrogen concentration; residual durability. Keywords: crack-like defects; fatigue crack growth rate; stress intensity factor; hydrogen concentration; residual durability. VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Evaluation of Increased Local Hydrogen Concentration in the Vicinity of Various Types of Defects in Low-Alloyed Steels Oksana Hembara a,b , Andriy Syrotyuk a, *, Olha Chepil a,b,с , Yaroslav Sapuzhak a , Nazar Hembara a VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Evaluation of Increased Local Hydrogen Concentration in the Vicinity of Various Types of Defects in Low-Alloyed Steels Oksana Hembara a,b , Andriy Syrotyuk a, *, Olha Chepil a,b,с , Yaroslav Sapuzhak a , Nazar Hembara a a Karpenko Physico-Mechanical Institute, National Academy of Sciences of Ukraine, 79601 Lviv, Ukraine b Institute of Civil Engineering and Building Systems, Lviv Polytechnic National University, 79000 Lviv, Ukraine c Bydgoszcz University of Science and Technology, 85-796 Bydgoszcz, Poland a Karpenko Physico-Mechanical Institute, National Academy of Sciences of Ukraine, 79601 Lviv, Ukraine b Institute of Civil Engineering and Building Systems, Lviv Polytechnic National University, 79000 Lviv, Ukraine c Bydgoszcz University of Science and Technology, 85-796 Bydgoszcz, Poland Abstract Abstract

* Corresponding author. Tel.: +38-032-263-1400; fax: +38-032-264-9427. E-mail address: asyrotyuk@gmail.com * Corresponding author. Tel.: +38-032-263-1400; fax: +38-032-264-9427. E-mail address: asyrotyuk@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.2024.04.028