| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lap fillet arc welded joint of a thin steel sheet which can improve fatigue strength of a lap fillet arc welded joint without sacrificing welding time, and to provide a method for manufacturing the same. <P>SOLUTION: The lap fillet arc welded joint is characterized in that a melted and solidified structure different from a weld metal formed by lap fillet arc welding is adjacently present, wherein the maximum depth of the structure is 20 to 50% of the thickness of a lower sheet and the width of the structure in a direction of the weld bead width at the surface of the lower sheet is 30 to 70% of the thickness of the lower sheet. The method is characterized by comprising assuming a site, on the surface of a steel sheet as the lower sheet of the welded joint, where a toe of weld of lap fillet weld bead is formed, forming the melted and solidified structure at the site previously assumed by a high energy irradiation means selected from laser, plasma arc, and TIG arc, and then performing lap fillet arc welding. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
