Method and device for overlapping welding of two coated metal sheets with a beam of high energy density

摘要

The invention concerns a method for overlapping welding of two coated metal sheets (1, 2) with a beam of high energy density (11), characterized in that it consists in splitting the beam (11) into a first sub-beam (12) passing through both coated metal sheets (1, 2) and forming in said zone a first molten metal bath (18) and into a non-through second sub-beam (13) forming a second molten metal bath (19) whereof the depth is less than the thickness of the upper coated metal sheet (1) and overlapping at least part of the first molten metal bath (18) for promoting evacuation of vapour from the coating material and directing on the second molten metal bath (19) a neutral gas jet with high ejection speed to form at the surface of the second molten metal bath a sink (22).