PSI - Issue 76

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ScienceDirect

Procedia Structural Integrity 76 (2026) 74–81

© 2025 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 scientific committee of the FDMD 2025 chairpersons Keywords: Wire + Arc Additive Manufacturing; surface waviness; fatigue; steel; Digital Image Correlation; infrared thermography Abstract Apart from producing new components, Wire + Arc Additive Manufacturing (WAAM) enables the remanufacturing of worn metallic parts, supporting a circular economy. However, the as-built surface often shows significant waviness resulting from the layered bead deposition, leading to stress concentrations and thus reduced fatigue life. Finishing operations are typically performed to mitigate those e ff ects, though omitting them could save processing time, energy consumption, and overall costs. This work investigates the fatigue performance of S355J2 steel components remanufactured by WAAM using EMK8 wire, retaining as-built surface waviness. A novel four-point bending specimen with a WAAM-filled groove was designed to replicate a surface repair. Two electric arc welding methods — conventional short-circuit and Cold Metal Transfer — were compared to assess the e ff ect of a di ff erent heat input. The former process resulted in higher heat input during material deposition. Compared to reference curves for S355J2 and bulk WAAMed EMK8 specimens, the fatigue strength of the remanufactured specimens was seen to be reduced. The as-built surface resulted in steeper slopes of the S-N curves compared to the polished reference materials. Crack initiation was determined by infrared thermography and was seen to occur between 6 and 50% of the total fatigue life, indicating that the majority of the total fatigue life consisted of crack propagation. The fatigue cracks were monitored by digital image correlation and were seen to propagate into the S355J2 substrate material, which can be considered as dominant for the crack growth rate. 5th International Symposium on Fatigue Design and Material Defects FDMD 2025 Fatigue performance of steel components remanufactured by wire + arc additive manufacturing with as-built surface waviness Robin Motte a, ∗ , Matthieu Vander Linden a , Kris Hectors a,b , Anil Sudhakar a ,WimDe Waele a,b a Soete Laboratory, Department of Electromechanical, Systems and Metal Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 46, BE-9052 Zwijnaarde, Belgium b FlandersMake @ UGent – Corelab MIRO, BE-9052 Zwijnaarde, Belgium

1. Introduction

Wire + Arc Additive Manufacturing (WAAM) is a type of additive manufacturing for metals that uses the com bination of an electric arc as heat input and wire as feedstock material (Knezovic´ and Topic´ (2019)). Apart from

∗ Corresponding author. E-mail address: robin.motte@ugent.be

2452-3216 © 2025 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 scientific committee of the FDMD 2025 chairpersons 10.1016/j.prostr.2025.12.289