| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To form a weld part having delayed breakdown resistance in the lapped portion of steel plates without causing any conspicuous welding deformation in a structural member in the laser beam welding of the structural member with a plurality of steel plates lapped thereon. <P>SOLUTION: In the laser beam lap welding method of forming a weld part by irradiating the lapped portion of steel plates of a structural member with a plurality of curved steel plates lapped thereon with a laser beam, (i) a plurality of steel plates which are curved at a curvature to satisfy following expression (1), and (ii) the laser beam is moved in the curved direction and the lapped portion of the steel plates is irradiated with the laser beam to form the weld part having excellent delayed breakdown resistance. The expression (1) is 1.2×(1/Ri)≥1/Ro≥1.05×(1/Ri) (wherein 1/Ro is the curvature of the steel plate arranged on the outer side of the radial direction of the curvature; and 1/Ri is the curvature of the steel plate arranged on the inner side of the radial direction of the curvature). <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
