| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a welding method in which arc stability is excellent even in the first layer (i.e., the bottom of a groove) of a multilayer welding and a stable weld penetration is obtained when performing a narrow groove butt welding of a thick steel sheet by a gas shielded arc welding method. <P>SOLUTION: The thick steel sheet having a thickness of ≥12 mm is used, and a narrow groove is made to be a root gap of ≤2 mm and a groove angle of ≤30°. The gas shielded arc welding of the first layer at the bottom of the narrow groove is performed under such conditions that: a welding speed is made to be 15-25 mm/sec; a QL value calculated by the formula, QL=I×E/[S×(G+5×tan θ)]/60 satisfies the range of 1.5-10.0; and a QH value calculated by the formula, QH=[G×S×60×(G+tan θ)/(I×E)]+tan θ satisfies the range of 1.0 or more. <P>COPYRIGHT: (C)2012,JPO&INPIT |
