JPS5947629B2 - One side back wave submerged arc welding method of butt joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-sided butt welding method, particularly suitable for welding and assembling the bottom plate of a storage tank.

In the conventional method, as shown in FIG. 1, a dovetail groove is formed in a butt weld joint 2 of a plate-shaped base material 1, and after discontinuous plate welding 3 is performed at the bottom of the groove, the groove is However, in this case, the actual welding is performed with the joint section being discontinuous due to the tack welding within the groove, making it extremely difficult to set the welding conditions. However, there were problems with welding defects such as insufficient penetration, poor fusion, and burn-through.

In order to solve the above-mentioned problems in the conventional case, the present invention forms a sufficiently large root face in the butt joint of a V-shaped or U-shaped groove, and performs tack welding within the groove by gouging. Form a dent by discontinuously discontinuing the desired location.
After performing tack welding to fill only this dent, the tack welding is finished with a grinder or the like to the same shape as the grooves before and after it, and continuous welding is performed to fill the V-shaped or U-shaped groove. This is a one-sided submerged arc welding method for butt joints. An embodiment of the present invention will be described with reference to the drawings. In FIGS. 2 to 4, V of the plate-shaped base material 1 is
Root face 4 large enough for the welded joint part of the mold groove
Form it.

Normally, the root face is about 1 mwL, but in the case of the present invention, it is 3 to 4 m7! Must be L or higher. Next, the portions to be tack welded within the groove 2 of the butt weld joint are discontinuously removed by gouging to form recesses 3. After performing tack welding 5 to fill only this recess 3, finish the upper part of the tack bead with a grinder until it has the same shape as the other groove surface that has not been tack welded, and then finish the V-shaped groove 2. For the actual welding, full penetration continuous welding is performed. According to the present invention, since tack welding is performed using the recesses formed in the groove by gouging, the throat thickness of the tack bead is ensured sufficiently, and the necessary strength of the tack bead can be easily obtained. Cracking of the tack bead can be completely prevented, geometrical discontinuities due to tack in the groove can be eliminated, and welding defects at the joint will not occur. Since there is no need to make the area particularly large, the arc energy needed to secure the back wave is small, making it economical. This is also effective in keeping the amount of distortion to a small level and improving the quality of the entire product. improves.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view for explaining the conventional method, Figures 2 and 3 are
The figure is a longitudinal sectional view for explaining the present invention, and FIG. 4 is a plan view as well.
3...Concavity, 4...Root face,
5...Tack welding.

Claims (1)

[Claims] 1. Form a root face of sufficient size in the butt joint of a V-shaped or U-shaped groove, and use gouging to discontinuously gouge the parts of the groove that should be tack welded to form a recess. After performing tack welding to fill only this dent,
Finish the temporary attachment part to the same shape as the groove shape before and after it, and
A method for welding one side of a butt joint using an underwave submerged arc, which is characterized by continuous welding of a type or U-type groove.