PSI - Issue 47

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 47 (2023) 190–194

27th International Conference on Fracture and Structural Integrity (IGF27) In-service degradation of rolled carbon steels: the role of damaging Hryhoriy Nykyforchyn a *, Olha Zvirko a , Oleksandr Oliynyk b , Oleh Venhryniuk a , Oleksandr Nesterov b , Oleksandr Tsyrulnyk a a Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine,

5, Naukova St., 79060 Lviv, Ukraine b Odessa National Maritime University, 34, Mechnikova St., 65029 Odesa, Ukraine

© 2023 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 the IGF27 chairpersons Abstract Nowadays, degradation of long-term operated structural steels is one of the main issues facing engineering. The problem is especially important at assessing the current state of structures made of the rolled steels and operated under the combined action of mechanical loading and corrosive environments, since hydrogen charging of steels under operation due to corrosion plays an important role in their degradation. The paper systematizes the signs of operational degradation of rolled carbon steels, as well as the main stages of degradation: deformation aging and development of dissipated damages in a metal bulk at nano- and micro scale. Operational degradation of steels implies changes in the microstructure, nano- and micro-mechanism of fracture and deterioration of their mechanical properties. The features of operational degradation of rolled carbon steels, namely the development of damages and delaminations between fibres along the rolling direction, are analysed. An influence of the operational degradation on anisotropy of the resistance to brittle fracture (impact toughness) of steels is considered. © 2023 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 the IGF27 chairpersons Keywords: rolled steel; mechanical properties; long-term operation; anisotropy; hydrogen embrittlement; dissipated microdamaging

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

2452-3216 © 2023 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 the IGF27 chairpersons

2452-3216 © 2023 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 the IGF27 chairpersons 10.1016/j.prostr.2023.07.011