| 摘要 |
PURPOSE:To prevent the cracking, embrittling, etc. that may be generated during the cooling process of weld zones and heat-affected zones by utilizing the ejection of a refrigerant in quickly cooling the heat after welding in the weld zones. CONSTITUTION:Base materials 8 are welded by a welding torch 1, whereby weld beads 9 are formed. In parallel with the progression of the torch 1, a refrigerant such as low temp. liquefied gas is ejected through a refrigerant ejection pipe 2 to the beads 9 or around the same to cool the beads 9, bonds and heat-affected zones quickly. A shielding plate 7 is provided between the torch 1 and the pipe 2 to prewvent or ease the influence of the ejection of the refrigerant upon a shielding gas for welding. It is possible to prevent the high temp. cracking, shrinkage cracking, etc. that may be produced during the cooling process of the weld zones effectively by this method. |
