| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent occurrence of blowhole and obtain good conditioned bead as to lap welding and lap fillet welding using laser and arc together even if there is no gap between galvanized steel sheets overlapped. SOLUTION: As to lap welding and lap fillet welding of the same galvanized steel sheets with a sheet thickness being between 0.2 mm and 6.0 mm and a galvanizing quantity being 10-120 g/m2 or those of galvanized steel sheet and other metal sheet with same sheet thickness and galvanizing quantity, there are such processes designed as laser emitting to the scheduled spot and gas metal arc welding after laser beam treatment. Thus, if the vicinity of fused and vaporized portions made by laser beam treatment is exposed to the arc, the arc discharge occurs constantly focusing at a spot exposed to laser beam and a high-speed welding becomes feasible. Because of this, in the case of lap fillet welding of galvanized steel sheets, the only edge part of top sheet can be welded without fusing a zinc-plated layer at a portion where the sheets are overlapped.</p> |
