JPS58103983A - Welding method by high energy density - Google Patents

Abstract

PURPOSE:To permit welding with high energy density without using any special restraining jigs or the like by forming preliminary weld beads having a tack welding effect by beam welding over the entire weld line prior to regular welding then performing regular welding. CONSTITUTION:Materials 1 to be welded are butted of grooves 2, and after the suitable places on the weld line are tack-welded in a simple way by TIG welding or the like, preliminary weld beads 3 having the depth at which the beads are not cracked by the thermal stress of regular welding 4 are welded by beam welding over the entire line prior to the regular welding. Such beads 3 as waste beads are welded and are remelted thoroughly by the regular welding 4, whereby the welding with high energy beam density is made possible easily without using any robust restraining jigs, etc. and without the possibility of the cracking in the tack welded parts in the stage of welding.

Description

[Detailed description of the invention] In welding using high energy density beams such as electron beams and laser beams, the beam diameter is small, so it is said that it is better to have the groove gap as small as possible, and Approximately -0.5 ml or less is required. Therefore, in order to prevent the groove from increasing during welding due to welding deformation, the groove is generally restrained using a jig during welding, or tack welding is performed using, for example, TIG welding. There are many. But in the latter case.

Although the former method eliminates the need for a restraining jig, there is a drawback that during deep penetration main welding, the tack joint may crack due to thermal stress, the groove gap may widen, and welding may be interrupted. .

In view of the above, in order to eliminate the drawbacks of conventional tack welding, the present invention aims to provide a beam welding method that does not have to worry about breaking the tack part during welding and interrupting welding. q before welding one.

We propose a high energy density welding method characterized by welding the preliminary weld bead by beam welding, which has a tack welding effect, as a sacrificial bead.

An embodiment of the method of the present invention will be described with reference to the drawings.

In FIG. 1, when a material to be welded 1 is brought together with two grooves, first, appropriate locations on the welding line are briefly welded by TIO welding or the like (not shown). If deep penetration main welding 4 is directly performed in this tack welded portion, it is sufficient that cracking occurs due to welding thermal stress.

Next, prior to the main welding 4, a preliminary welding bead 3 having a depth of 0.05 cm that will not break due to the thermal stress of the main welding 4 is welded all the way by beam welding. The conditions are chosen such that this preliminary weld bead 3 is completely remelted by the main welding 4 and no preliminary weld bead 3 remains after welding.

When the plate thickness is thick, as shown in Figure 2.

The pre-welding bead 3', 3 can be carried out repeatedly. In other words, if the welding heat input of the preliminary weld bead 3', which has the necessary penetration depth to avoid cracking due to the thermal stress of the main weld 4, is large and excessive thermal stress still occurs, this preliminary weld bead 3' A preliminary weld bead 3 is applied by regarding this as the main weld 4 shown in FIG.

Thus, in the method of the present invention, since the preliminary welding is gauze welding, the plate attachment effect is very large compared to the tack welding at the time of groove alignment. A penetration depth of 5 mm or less is sufficient. For this preliminary welding, the tack welding at the time of groove alignment is very simple, so it is not necessary to use a sturdy restraint jig etc. to perform welding without worrying about opening the groove gap during welding. Can be implemented.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams of two embodiments of the method of the invention. 1: Material to be welded, 2: Groove, 3.3': Preliminary weld bead,
4: Main welding.

Claims (1)

[Claims] A high energy density welding method characterized by welding a preliminary weld bead by beam welding, which has a tack welding effect, as a waste bead prior to main welding.