| 摘要 |
PURPOSE:To obtain a welded joint having the large difference in thickness of the welding quality to resist continuous strip passing. CONSTITUTION:At the time of joining a thin metallic steel strip 1 to a thick metallic steel strip 7, a laser beam welding torch and a MIG welding torch are arranged in the front and in the rear, respectively and a laser beam irradiates so as to pass through a cross section of thin steel strip thickness. A corner part of the thick metallic steel strip 7 is aimed at to perform MIG welding by a MIG welding wire. Since laser beam weld metal 9 is formed for the thickness of the thin metallic steel strip 1 and then, the corner part of the thick metallic steel strip 7 is aimed at to perform MIG welding by the MIG welding wire, the shape shown by a steel strip shape estimated line 8 before welding becomes smooth and MIG weld metal 10 is formed on the laser beam weld metal 9. |
