Fraunhofer Institute for Production Systems and Design TechnologyCombination of two welding processes for thick plates: laser hybrid and narrow-gap submerged-arc welding
Laser Hybrid and Narrow Gap Submerged Arc Welding for Thick-walled Steel Structures
With this process variant, high sheet thicknesses can be welded with a lower number of layers and lower heat input.
How exactly does the combination of the two welding processes work?
A thick plate specimen is prepared for laser hybrid welding with an engineered zero gap.
Weld seam of the combined laser hybrid and submerged arc welding process of Fraunhofer IPK.
Schematic illustration of the welding layer sequence in the combination of laser hybrid and submerged arc welding.
Hybrid laser arc welding technology is increasingly proving to be an innovative alternative to other methods in welding manufacturing.
Researchers at Fraunhofer IPK are developing a new approach in which the efficient high-power laser hybrid process can be used in combination with narrow-gap submerged-arc welding to join thick-walled structures.
Combining the two welding processes will reduce manufacturing time and increase profitability while improving quality and competitiveness for many SMEs. It also significantly increases productivity in the manufacture of towers for wind turbines.
It has many economic advantages:
- Large penetration depth and a therefore resulting reduced number of welding layers.
- A low thermal load on the base material due to reduced heat input.
- By using electromagnetic weld pool support, thick-walled steel structures made of modern, high-strength and heat-sensitive steels can be welded efficiently.
- This eliminates the need for expensive reworking of the weld root.
- Better root quality also leads to increased fatigue strength of the welded structure.
With this process variant, high plate thicknesses can be welded with a lower number of layers and lower heat input. This also reduces the cost of finishing, e.g. for stress relief annealing due to higher thermal load of the workpieces to be welded and the resulting residual stresses in the component.
The one-sided accessibility ensures that expensive handling techniques are not required. In addition, thick-walled components can be conditionally turned, which is a significant advantage to welding in position/opposite position.
Result:
- Fault-free welding of longitudinal and circumferential welds, e.g. in the manufacture of towers for wind turbines.
- Consistent quality due to a high degree of automation.
- A reduced number of filler layers means less energy consumption and filler materials.
Thanks to the expansion of production technologies and the use of new construction materials, efficient manufacturing is now possible. this was not technically or economically feasible with previous conventional welding processes.
The solution is interesting for these industries:
- Offshore oil and gas industry
- Wind power industry
- Large-diameter pipe manufacturing