Üstündağ, ÖmerÖmerÜstündağBakir, NasimNasimBakirGumenyuk, AndreyAndreyGumenyukRethmeier, MichaelMichaelRethmeier2023-07-102023-07-102022https://publica.fraunhofer.de/handle/publica/44533610.1016/j.procir.2022.08.0672-s2.0-85141896326The study deals with the influence of the heat input and the resulting cooling times on the microstructure and Charpy impact toughness of single-pass laser hybrid welded 20-mm thick high-strength steel S690QL. The main focus is on the change of the mechanical properties over the entire seam thickness. The cooling times were measured in-situ using a pyrometer and an optical fibre in three different depths of the seam where Charpy impact test specimens were also later taken. Thereby, three different heat inputs from 1.3 kJ/mm to 2 kJ/mm were investigated. Despite the observed decreased values of both t8/5-cooling time and the Charpy impact toughness in the root part of the seam, the required impact toughness of 38 J/cm2 could be reached in dependance on applied heat input, especially at the heat input of 1.6 kJ/mm.enAC magnet backingCharpy impact toughnesshigh-strength steellaser hybrid weldingS690QLjournal article