| 摘要 |
PROBLEM TO BE SOLVED: To provide an electro gas arc-welding method and an electro gas arc-welding apparatus which enable the efficient discharge of slag.SOLUTION: A flux-cored wire which keeps a steel shell filled with flux, contains a specific amount of C, Si, Mn, Mo, Ti and SiO, restricts Al, S, P, TiOand AlOto a specific amount or less, has the remainder consisting of Fe and inevitable impurities, and has a composition which satisfies the following numerical expression (A) is used for a welding wire 5. A material which has a groove with a curvature in a surface in contact with beveling with a groove width W of (1.1×a) - (2.5×a)mm, a groove depth D of 0.5 - 5.5 mm, and a ratio (W/D) of the groove width W to the groove depth D of 5.0 - 80.0 where the beveling width is a is used for a slidable copper backing 2 to control a rise speed of a welding torch 4 on the basis of welding current so that the projection length of the welding wire 5 may be constant with the constant feed speed of the welding wire 5.SELECTED DRAWING: Figure 1 |
