| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a welding method which can improve energy efficiency while suppressing welding defects in manufacturing a fuel tank for an automobile from a hexa-valent chromium free plated steel sheet. <P>SOLUTION: The hexa-valent chromium free plated steel sheet, such as an Sn-Zn plated steel sheet, is processed by drawing. A pair of half-bodies having a flange portion formed along the outer periphery of the recessed portion caused by the drawing are formed. A pair of the half-bodies are arranged such that the respective recessed portions face to each other on the inner surface side, and the respective flange portions are opposed to each other. The welding is carried out by moving a laser beam along the flange portion opposed to each other. The welding beam is moved so as to trace triangles 11, 12, 13 in welding, and saw tooth shape welded portions P are formed on the flange portion. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
