Improvement in steel utilisation and manufacturing by recent break-through in high-power fibre laser welding (Fiblas)

The aim of the Fiblas project was to conduct innovative research to generate knowledge and technology to increase industrial efficiency in major load-bearing welded steel structures, exploiting the specific advantages of high-power fibre laser welding. Different material grades for the use of pipe and shipbuilding applications were joined with fibre laser-based autogenous and hybrid welding processes. Process parameters for welding with high-power fibre lasers were established and welding equipment was developed for different welding tasks. An extensive assessment of samples welded with different processes from ship steel and pipe steel was carried out. The capability of the fibre laser-based welding processes for different applications was demonstrated. This includes T-joint welding for shipbuilding applications, longitudinal welding for pipe making, and girth welding for onshore and offshore pipe laying. Economic benefits for the industrial users arise, for example, from the saving of filler wire, increased welding speed and avoiding SAW processes, all of which contribute to increased productivity. On the technical side, the heat input of the laser-based processes is reduced compared with SAW processes. Therefore, the mechanical properties of the HAZ can be improved and distortion can be reduced. Exploitation has included the transfer of Fiblas results into full-scale industrial applications for welding in shipyards. Thus, the project can be seen as very successful.