| 摘要 |
PURPOSE:To prevent scattering of the plated layer to eliminate welding defects, by superposing and welding weld zone provided with space parts on welding faces in the laser welding method where one welding face, at least, consists of the coated layer of materials having a melting point lower than its base metal. CONSTITUTION:In laser welding for materials (for example, zinc plated steel plate) whose contact face of at least one of metal materials 1 and 2 to be welded is coated with materials 3a, 3b, 4a and 4b having a melting point lower than its base metal, concave part 6 of approximately 50mum depth which should become superposition space part 5 for welded materials 1 and 2 is formed on the junction face (in the plated layer 4a side) of welded material 2. Concave part 6 has a broder area than the area surrounding mutual fused parts of materials 1 and 2, and concave part 6 is irradiated with laser beam 7 and is welded. Low-melting point materials 3b and 4a (3a is scatterred to the external instantaneously) molten explosively escape into space part 5, thereby obtaining practical weld strength. |
