Laser-Assisted Flux-Cored Arc Welding Underwater

The underwater welding process using flux-cored electrodes presents a significant challenge in terms of reliable arc ignition and stability. Therefore, the aim of this study is to investigate an underwater welding process that combines laser radiation with an arc to improve seam quality by introducing additional energy into the process zone. To examine the arcs safe ignition and stability during welding, various process parameters are evaluated by analyzing the resulting arc current and voltage characteristics, as well as the spectral process emissions. S235JR (1.0038) steel samples with a thickness of 10 mm are welded in a bead-on-plate configuration using flux-cored wire. The laser radiation with a wavelength of 1030 nm and a power of up to 2000 W has a supporting effect, influences the arc positively in that it fluctuates less and ensures a more uniform weld. The laser-assisted flux-cored welding process resulted in an improved seam quality with reduced surface pores and increased weld penetration depth and width. The requiered laser power for arc stabilization was about 20-30 % of the total energy balance. The arc current and voltage characteristcs also showed a reduction of up to 70 % in fluctuation. Overall, this study demonstrates that the laser-assisted flux-cored welding process presents a promising approach to overcome the challenges of underwater welding.