| 摘要 |
PURPOSE:To facilitate an assembling work while preventing the generation of cold crack and decreasing weld deformation in the stage of tack-welding base materials of high tension steel by utilizing a TIG arc as a concentrating heat source for preheating or post heating the base materials. CONSTITUTION:A TIG arc is used as a heat source for preheating or post heating of base materials and the preheating or post heating is performed with a weld heat input regulated at about >=280kJ/100mm. in the stage of tack-welding high tension steel having about >=50kg/mm.<2> tensile strength by using a coated arc welding rod. Said value is controlled by the total time for the preheating and post heating. The quantity of heat input in the preheating or post heating is regulated at about >=70kJ/100mm. when the tack-welding is to be performed by TIG welding. The generation of the cold crack in the high tension steel is thus prevented; moreover, the assembling time in welding is reduced, and the deformation by welding is decreased. |
