Laser beam submerged arc hybrid welding: A novel hybrid welding process

The currently predominant joining process for constructional steel in the sheet thickness range of 40 mm, as is customary in pipeline and bridge construction, is submerged arc welding. Due to the large number of welding layers required, a high quantity of energy, expensive welding filler material, and also distortion are introduced into the component. The laser beam submerged arc hybrid welding combines the conventional submerged arc welding process with a high-energy laser beam welding process to form a hybrid process. With this process, sheets with a thickness of up to 40 mm can be joined in butt joints in just two welding layers. In this paper, the hybrid character of this method is emphasized. First, the geometric shape of the melt pool in the cross section is discussed and later the mixing of both melt pools is verified by energy-dispersive x-ray spectroscopy analyses. In addition, results when joining gaps are present are demonstrated and discussed.