New laser welding processes shall make the welding of thick metal sheets in shipbuilding more efficient and less expensive. (image: Meyer Werft/M. Wessels)
Partners of a joint research project in Germany are looking develop new diode laser beam sources with a maximum output power of up to 60kW in continuous-wave mode in order to establish fast, high-quality laser welding processes for steel sheet thicknesses of up to 30 millimetres in shipbuilding and other maritime applications.
The partners of the project will also be developing concepts for ensuring laser safety when using such high output powers.
The project ‘Thick Metal Sheet Welding by High-Power Diode Lasers for Maritime Applications’ (DIOMAR) is being carried out by diode laser manufacturer Laserline – which will be responsible for the development of the new high-power laser diode sources – research institute Laser Zentrum Hannover, shipbuilding firm Meyer Werft, and electronics manufacturer Held Systems. The project is funded by the German Federal Ministry for Economic Affairs and Energy.
According to the partners, the processes for joining maritime steel components have a great development potential in terms of production costs and productivity: the frequently used submerged arc welding is comparatively slow and involves significant workpiece distortion. Laser-arc hybrid welding, as an alternative process, requires labour-intensive edge preparation and is not very flexible.
The aim of the DIOMAR project is to establish new laser welding processes based on high-power lasers in the maritime sector. (Image: Meyer Werft/I. Fiebak)
While submerged arc welding does have its disadvantages, for large steel sheet thicknesses in the range of 12 millimetres to 30 millimetres, no method has been able to prevail against it, the partners say. They therefore intend to change this through the development of robust, pure laser welding processes, which by achieving high-quality joints with high welding speeds, will reduce the costs for edge preparation compared to existing joining methods.
The application-oriented development of the project is taking place in both a laser laboratory and in a shipyard-like test environment. This makes it possible to quickly test, evaluate and optimise the new processes, which, according to the partners, will complement or even replace the existing ones.
In developing safety concepts for the new high-power diode laser beam sources, the Laser Zentrum Hannover will be investigating ways to handle the expected large quantities of emitted hazardous substances from the laser processing zone.
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