Issue 78

A. Sancak et alii, Fracture and Structural Integrity, 78 (2026) 186-206; DOI: 10.3221/IGF-ESIS.78.11

Effects of seawater corrosion, notch timing, and test temperature on the impact toughness of AISI 1008 marine chain steel

Abdülmelik Sancak, Adem Canda ş , Serpil Kurt, C. Erdem İ mrak Faculty of Mechanical Engineering, İ stanbul Technical University, Türkiye

sancak17@itu.edu.tr, http://orcid.org/0000-0003-4004-5468 candas@itu.edu.tr, http://orcid.org/0000-0002-9951-9122 kurtserp@itu.edu.tr, http://orcid.org/0000-0003-0946-8745 imrak@itu.edu.tr, http://orcid.org/0000-0003-4428-0158

Citation: Sancak, A., Canda ş , A., Kurt, S., İ mrak, C.E., Effects of Seawater Corrosion, Notch Timing, and Test Temperature on the Impact Toughness of AISI 1008 Marine Chain Steel, Fracture and Structural Integrity, 78 (2026) 186-206.

A BSTRACT . Marine chains operate under corrosive and impact-prone conditions, yet the combined influence of seawater exposure, notch condition and test temperature on their impact toughness remains insufficiently clarified. This study addresses this gap by examining the Charpy V-notch impact response of AISI 1008 steel extracted from galvanized marine chain links after exposure to seawater and substitute seawater. Rather than treating corrosion damage only as mass loss, the study focuses on how corrosion history, notch timing and local material variability jointly affect absorbed impact energy. The results showed a pronounced temperature sensitivity in the uncorroded condition, with absorbed energy decreasing sharply from room temperature to sub-zero temperatures. After 30 days of immersion, both seawater and substitute seawater reduced the average impact energy at 0 °C, while seawater produced higher mass loss. However, the absorbed energy did not scale directly with corrosion loss. Considerable scatter was observed even under nominally identical conditions. Near-fracture cross-sectional SEM highlighted local ferrite–pearlite heterogeneity and discontinuity-like features in selected regions. The findings demonstrate that the impact resistance of the investigated marine chain steel cannot be assessed solely from average corrosion loss or hardness values, and highlight the need to consider notch condition, temperature and microstructural variability in structural integrity evaluations. K EYWORDS . AISI 1008 steel, Marine chains, Seawater corrosion, Charpy V notch impact test, Impact toughness, Structural integrity.

Received: 29.06.2026 Accepted: 17.08.2026 Published: 18.08.2026 Issue: 10.2026

Copyright: © 2026 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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