PSI - Issue 82

Goran Vukelić et al. / Procedia Structural Integrity 82 (2026) 3– 8 Vukelić et al./ Structural Integrity Procedia 00 (2026) 000–000

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4. Discussion and conclusion The trends observed in Fig. 2 demonstrate a gradual decrease in the mass of specimens exposed to the marine environment, indicating progressive material degradation over time. This mass loss is more pronounced in the AM and CM-AM welded specimens compared to the CM welded ones. A substantial reduction in mass is observed after three months of exposure, with the most significant losses recorded for the CM-AM specimens. The approximation equations presented in Fig. 2 provide a useful basis for predicting the time-dependent mass loss of AISI 316L stainless steel. As shown in Fig. 3, the apparent ultimate tensile strength of all specimen types decreased with prolonged exposure. The reduction was most pronounced for CM-AM specimens, indicating a greater susceptibility to environmental degradation at the welded interface. In contrast, AM specimens exhibited a relatively uniform decline in tensile strength, with only a slight reduction observed over time. The relationship between mechanical properties and exposure duration is illustrated by approximation curves fitted to the experimental data, effectively capturing the observed degradation trends. Future research should focus on a more detailed characterization of corrosion pit formation on the material surface, as such pits often act as crack initiation sites that can compromise structural integrity. To achieve a more comprehensive understanding of the long-term behaviour of AISI 316L stainless steel in marine conditions, the exposure duration should be extended to 12 or 24 months. It would also be valuable to compare the results obtained from natural seawater exposure with those from standardized accelerated corrosion tests conducted under controlled laboratory conditions. Further studies may additionally consider the influence of varying marine environments, including the effects of wave action, splash zones, and tidal fluctuations. A comparative analysis of surface degradation among the base metal, weld metal, and heat-affected zone (HAZ) would provide further insight into localized corrosion behaviour and mechanical degradation mechanisms. This represents the intended direction for future continuation of the present study. Acknowledgements Funded by the European Union – NextGenerationEU, under the University of Rijeka project PU-175, uniri-iz-25 111, "Assessment of 3D-Printed Material Corrosion Using Artificial Intelligence - 3D-Cortelligence". References Bogdanovic, M., Ivosevic, S., 2025. Offshore Wind Energy Potential: Assessing Capacity Factor and Electricity Generation in Montenegro. Pomorstvo 39, 150–166. https://doi.org/10.31217/p.39.1.12 Braun, M., Schubnell, J., Sarmast, A., Subramanian, H., Reissig, L., Altenhöner, F., Sheikhi, S., Renken, F., Ehlers, S., 2023. Mechanical behavior of additively and conventionally manufactured 316L stainless steel plates joined by gas metal arc welding. Journal of Materials Research and Technology 24, 1692–1705. https://doi.org/10.1016/j.jmrt.2023.03.080 Brdar, D., Lopac, N., Lesch, A., Jurdana, I., 2025. Design of a Conceptual Underwater Wireless Communication System Integrating Electromagnetic and Optical Technologies. Pomorstvo 39, 141–149. https://doi.org/10.31217/p.39.1.11 Dantas, A., Dantas, R., Cipriano, G.P., de Jesus, A., Lesiuk, G., Fonseca, C., Moreira, P., Correia, J.A.F.O., 2024. A methodology to evaluate seawater corrosion on quasi-static tensile properties of a structural steel. Engineering Failure Analysis 164, 108613. https://doi.org/10.1016/j.engfailanal.2024.108613 Ermakova, A., Mehmanparast, A., Ganguly, S., 2019. A review of present status and challenges of using additive manufacturing technology for offshore wind applications, in: Moreira, P., Tavares, P.J.S. (Eds.), 3RD INTERNATIONAL CONFERENCE ON STRUCTURAL INTEGRITY (ICSI 2019), Procedia Structural Integrity. Presented at the 3rd International Conference on Structural Integrity (ICSI), Elsevier Science Bv, Amsterdam, pp. 29–36. https://doi.org/10.1016/j.prostr.2019.08.005 Ettefagh, A.H., Guo, S., Raush, J., 2021. Corrosion performance of additively manufactured stainless steel parts: A review. Addit. Manuf. 37, 101689. https://doi.org/10.1016/j.addma.2020.101689 Hamada, A., Jaskari, M., Abd-Elaziem, W., Allam, T., Järvenpää, A., 2025. Comparative Study of Fatigue Behavior and Microstructural Evolution in As-Built and Heat-Treated Additively Manufactured 316L Stainless Steel. Procedia Structural Integrity, European Conference on Fracture 2024 68, 465–471. https://doi.org/10.1016/j.prostr.2025.06.083 Hoque, K.N., Presuel-Moreno, F., 2025. A Long-Term Experimental Study on Evaluating Corrosion Currents in Reinforced Concrete for Marine Structures. Scientific Journal of Maritime Research - Pomorstvo 39, 173–185.