Laserstrahl-MSG-Hybridschweißen von Feinkornbaustählen für den Einsatz im Stahlbau

Laser-GMA hybrid welding of high-strength fine-grained steels using in steel construction.

For industrial manufacturing of ships, pipelines or cranes, thick plates made of high-strength fine-grained steels are used, which are characterized by advantages with respect to weldability and mechanical properties. Steel structures made of thick plates are conventionally joined using multi-layer arc welding procedures, but this causes long production times and requires a high consumption of filler material. A potential alternative is laser-GMA hybrid welding technology, which combines the best advantages of laser beam welding with those of conventional gas metal arc welding. In the context of these investigations, the laser-GMA hybrid welding with an integrated inductive preheating process, and a laser-GMA hybrid welding process with a trailing GMA-welding process were developed for welding high-strength fine-grained steels with the grades of S690QL (t = 15 mm and t = 20 mm), L485MB (t = 23 mm) and L450MB (t = 30 mm). The results show that it is able to generate high quality welding seams by using a single-layer laser-GMA hybrid welding process. Furthermore, the robustness of the laser-GMA hybrid welding process for bridging gap widths as well as vertical edge offsets could be demonstrated.