PSI - Issue 68

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect

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ScienceDirect

Procedia Structural Integrity 68 (2025) 1237–1244

European Conference on Fracture 2024 Fracture behavior of simulated heat affected zones in S690QL high strength steel D. Tomerlin a *, D. Kozak a , T. Vuherer b , N. Enzinger c , M. C. Poletti c , N. Gubeljak b a University of Slavonski Brod, Mechanical Engineering Faculty in Slavonski Brod, Trg I. B. Mažuranić 2, 35000 Slavonski Brod, Croatia b University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor, Slovenia c Graz University of Technology, Institute of Materials Science, Joining and Forming, Kopernikusgasse 24/I, 8010 Graz, Austria Abstract The fracture mechanics characterisation of different locations in the heat-affected zone (HAZ) is not possible due to steep gradients and large variability. The Gleeble thermo-mechanical simulations, can reproduce the characteristic HAZ microstructures, in a volume convenient for testing. In this study, the GMAW welding thermal cycles are simulated on High Strength Steel (HSS) S690QL specimens. To reproduce two-pass welding HAZ microstructures, two consecutive thermal cycles are physically simulated. Testing of tensile properties, ASTM E1820 fracture toughness and ASTM E647 fatigue crack growth is done. Tensile tests show that the increase of reheat temperatures in 2 nd cycle leads to strength decrease. The J IC fracture toughness and Stress intensity factor (SIF) K JIC values are highest for CGHAZ region, being reheated to 1250 °C in 2 nd welding cycle. Fatigue crack growth rate tests were performed for each characteristic HAZ microstructure. The CGHAZ zone has the lowest resistance to fatigue crack growth. © 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 ECF24 organizers European Conference on Fracture 2024 Fracture behavior of simulated heat affected zones in S690QL high strength steel D. Tomerlin a *, D. Kozak a , T. Vuherer b , N. Enzinger c , M. C. Poletti c , N. Gubeljak b a University of Slavonski Brod, Mechanical Engineering Faculty in Slavonski Brod, Trg I. B. Mažuranić 2, 35000 Slavonski Brod, Croatia b University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor, Slovenia c Graz University of Technology, Institute of Materials Science, Joining and Forming, Kopernikusgasse 24/I, 8010 Graz, Austria Abstract The fracture mechanics characterisation of different locations in the heat-affected zone (HAZ) is not possible due to steep gradients and large variability. The Gleeble thermo-mechanical simulations, can reproduce the characteristic HAZ microstructures, in a volume convenient for testing. In this study, the GMAW welding thermal cycles are simulated on High Strength Steel (HSS) S690QL specimens. To reproduce two-pass welding HAZ microstructures, two consecutive thermal cycles are physically simulated. Testing of tensile properties, ASTM E1820 fracture toughness and ASTM E647 fatigue crack growth is done. Tensile tests show that the increase of reheat temperatures in 2 nd cycle leads to strength decrease. The J IC fracture toughness and Stress intensity factor (SIF) K JIC values are highest for CGHAZ region, being reheated to 1250 °C in 2 nd welding cycle. Fatigue crack growth rate tests were performed for each characteristic HAZ microstructure. The CGHAZ zone has the lowest resistance to fatigue crack growth. © 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 ECF24 organizers © 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 ECF24 organizers Keywords: Welded joint heterogeneity; Thermo-mechanical simulations; High strength steel; Fracture; Fatigue crack growth Keywords: Welded joint heterogeneity; Thermo-mechanical simulations; High strength steel; Fracture; Fatigue crack growth

* Corresponding author. Tel.: +385-98-176-7122. E-mail address: dtomerlin@unisb.hr * Corresponding author. Tel.: +385-98-176-7122. E-mail address: dtomerlin@unisb.hr

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 ECF24 organizers 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 ECF24 organizers

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 ECF24 organizers 10.1016/j.prostr.2025.06.193