PSI - Issue 59

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 59 (2024) 112–119

© 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 The total length of main gas pipelines of Ukraine, which have been in operation for more than 40 years, is 29,000 km, that is, 76% of their total length. Long-term operation leads to gradual degradation of the steel structure. This leads to changes in the initial mechanical properties of pipeline steels, which determine the durability of the material as a structural element. The estimation of the material degradation and changes in the mechanical properties of steels of long-term operated gas pipelines was carried out using the σ YS /σ UTS parameter. It was established that the change in plasticity characteristics and σ YS /σ UTS parameter is not a real reserve of plasticity of the studied pipe steels. This is grounded by the influence of hydrogen absorbed by the metal of the pipeline, which penetrates from the transported hydrogen-containing environment during long-term operation. The influence of hydrogen volume concentration C H on the strength of low- alloyed 17H1S and 10H2BТ steels was evaluated. The obtained results were compared with the hydrogen critical concentration cr H C in the metal of X52 and X70 pipe steels. A conclusion about the hydrogen influence on the durability and risk of failure of main pipe elements was made. The zones of damaging factors action in the case of main gas pipelines accident, which are the basis for calculation of the ecological consequences of accidents, have been determined. © 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) Impact of Long-Term Operation on Reliability and Durability of Natural Gas Pipeline: Potential Environmental Consequences of Accidents Roman Hrabovskyy a, *, Yevstakhiy Кryzhanivsky y a , Oleh Tuts a , Oleh Mandruk a , Volodymyr Tyrlych a , Volodymyr Artym a , Yaroslav Sapuzhak b a Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine, 76019, Ivano-Frankivsk, Ukraine b Karpenko Physico-Mechanical Institute, National Academy of Sciences of Ukraine, 79601, Lviv, Ukraine

* Corresponding author. Tel.: +38-034-272-7182; fax: +38-034-272-7182. E-mail address: hrabovskyy.r@gmail.com (Roman Hrabovskyy)

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.2024.04.017