PSI - Issue 77

ScienceDirect Structural Integrity Procedia 00 (2026) 000–000 Structural Integrity Procedia 00 (2026) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 77 (2026) 41–48

© 2026 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 ICSI organizers Abstract The aim of this study was to develop a methodology to investigate hydrogen effects on crack growth resistance in low alloy ferritic steels using cathodic hydrogen precharging with the focus on stable crack growth in pressure vessel steel grade P355NH. Inert gas fusion measurements (IGF) were performed to determine hydrogen uptake and estimate diffusion behavior. Numerical calculations allowed a first prediction of the concentration profile in compact tension specimens. To assess the influence of internal hydrogen on crack growth resistance, fatigue precracking was performed and J - ∆ a -curves were measured. Accelerated fatigue crack growth was observed for high stress intensities and low frequencies. In the J - ∆ a -analysis, the crack growth resistance in hydrogen charged material was reduced in contrast to uncharged specimens. However, no unstable crack growth was perceivable. In conclusion, the steel remains predominately ductile with the applied charging conditions. The findings from fracture mechanical investigation were further confirmed using optical and scanning electron microscopy. © 2026 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 ICSI organizers Keywords: Hydrogen embrittlement; fracture mechanics; crack growth resistance 1. Introduction Hydrogen technologies exhibit a great potential for the decarbonization of transport and industry as well as the generation and storage of renewable electrical energy, but are still facing some economic and technical challenges (Yue et. al. (2021), Rosen et al. (2016)). A potential hazard from an engineering point of view is material degradation International Conference on Structural Integrity Influence of hydrogen on crack growth resistance of steels for energy infrastructure applications A. Hell a, *, A. Molz a , T. Werning a , K. Schisler a , H.-G. Herrmann a,b a Chair for Lightweight Systems, Dept. of Materials Science and Engineering, Saarland University, Campus E3.1, 66123 Saarbrücken, Germany b Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3.1, 66123 Saarbrücken, Germany Abstract The aim of this study was to develop a methodology to investigate hydrogen effects on crack growth resistance in low alloy ferritic steels using cathodic hydrogen precharging with the focus on stable crack growth in pressure vessel steel grade P355NH. Inert gas fusion measurements (IGF) were performed to determine hydrogen uptake and estimate diffusion behavior. Numerical calculations allowed a first prediction of the concentration profile in compact tension specimens. To assess the influence of internal hydrogen on crack growth resistance, fatigue precracking was performed and J - ∆ a -curves were measured. Accelerated fatigue crack growth was observed for high stress intensities and low frequencies. In the J - ∆ a -analysis, the crack growth resistance in hydrogen charged material was reduced in contrast to uncharged specimens. However, no unstable crack growth was perceivable. In conclusion, the steel remains predominately ductile with the applied charging conditions. The findings from fracture mechanical investigation were further confirmed using optical and scanning electron microscopy. © 2026 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 ICSI organizers Keywords: Hydrogen embrittlement; fracture mechanics; crack growth resistance 1. Introduction Hydrogen technologies exhibit a great potential for the decarbonization of transport and industry as well as the generation and storage of renewable electrical energy, but are still facing some economic and technical challenges (Yue et. al. (2021), Rosen et al. (2016)). A potential hazard from an engineering point of view is material degradation International Conference on Structural Integrity Influence of hydrogen on crack growth resistance of steels for energy infrastructure applications A. Hell a, *, A. Molz a , T. Werning a , K. Schisler a , H.-G. Herrmann a,b a Chair for Lightweight Systems, Dept. of Materials Science and Engineering, Saarland University, Campus E3.1, 66123 Saarbrücken, Germany b Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3.1, 66123 Saarbrücken, Germany

* Corresponding author. Tel.: +49-681-302-3928; fax: +49-681-9302-5901. E-mail address: alexander.hell@uni-saarland.de * Corresponding author. Tel.: +49-681-302-3928; fax: +49-681-9302-5901. E-mail address: alexander.hell@uni-saarland.de

2452-3216 © 2026 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 ICSI organizers 2452-3216 © 2026 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 ICSI organizers

2452-3216 © 2026 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 ICSI organizers 10.1016/j.prostr.2026.01.007