METHOD FOR WELDING FLAT PLATE MADE OF ULTRA-HEAVY STEEL PLATE

摘要

PROBLEM TO BE SOLVED: To facilitate groove alignment, not to be required other than local heating and to unnecessitate tack welding by executing arc welding while preheating the vicinities on both sides of the weld zone between flat plates consisting of steel plate having specified thickness, width and length together with the end parts on the opposite side of the weld zone to a specific temperature. ;SOLUTION: By butt-welding half bottom plates (flat plates) 11, 12 whose thickness T is ≥100 mm, width is ≥20 times the thickness T and length is ≥1.5 times the width, a bottom plate 13 is made. The arc welding is executed while preheating the vicinities on both sides of the weld zone (weld line) 22 of the half bottom plates (flat plates) 11, 12 and the nd parts on the opposite side of the weld zone to 100-150°C with the heaters (heating means) 23-26 for preheating. It is preferable to take the preheating width as 1-3 times the thickness T. As the arc welding, submerged arc welding, MIG welding or TIG welding is used. By heating the vicinal parts on both sides of the weld zone between the flat plate and the end parts on the opposite side of the weld zone of the flat plate to a specific temperature, the thermal stress by which the camber on the plane on the verge of generating is cancelled.;COPYRIGHT: (C)2000,JPO