| 摘要 |
A laser lap welding method, for a galvanized steel sheet, includes preparing two steel sheets in lap configuration, at least one of which is the galvanized steel sheet, so that a galvanized layer thereof is located at an interface of the steel sheets; and irradiating a surface of any one of the two steel sheets in an overlapped region with a laser to perform lap welding. The welding is performed by applying the laser to travel at a predetermined power density and at a predetermined traveling velocity so as to partially and temporarily form an elongated hole in a molten pool extending backward from a laser irradiation spot at least in the steel sheet on the surface side, whereby metal vapor produced by laser irradiation is vented through the elongated hole backward in a laser traveling direction and in a laser irradiation source side. |
