PURPOSE: To efficiently manufacture while keeping a box type structural material having a diaphragm inside of four side panels thereof at a high quality.
CONSTITUTION: Two webs 1A with welding grooves, two flanges 1B without grooves and a diaphragm 3 with columnar spaces for welding on four sides are temporarily welded to give a box type structural material an assembled state. At first, the welding grooves at four corners are corner-welded, then the flanges 1B are pierced to provided conducting holes leading to columnar spaces along the interior of the webs 1A to perform a CES-welding, and then the webs 1A are pierced to provide continuity holes conducting to the columnar spaces along the interior of the flanges 1B to perform an electroslag-welding.
TSUKAMOTO KATSUO
YAMASHITA TATSUO
| JPS61180679A | 1986-08-13 | |||
| JPH01224168A | 1989-09-07 |