| 摘要 |
PURPOSE:To join plural metal sheets, and to securely block that a stress concentration occurs at a peripheral part where the stretch-flanging of a metal sheet is formed. CONSTITUTION:A combined blank member 10 is constituted by performing a butt welding of a front pillar part 12 and a center pillar part 14, etc., on a side sill part 16. Softened parts 34, 36 and 38 are provided through a softening treatment by annealing with the radiation of a laser beam near the peripheral parts 28, 30 and 32, etc., of the metal sheet, including the welded edge part 22 of the front pillar part 12 and the welded edge parts 24 and 26 of the center pillar part 14. |
