JPS5928436B2 - Electron beam welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam welding method in which filler wire is supplied into a groove gap.

Electron beam welding has a high energy density, so deep penetration can be achieved, and there is no need to prepare a groove, so even thick plates can be welded by I-groove pass welding, making it an extremely efficient welding method. Furthermore, when the groove gap width is close to omWL, a filler wire for filling the groove is not required, which saves resources.

However, if you have a long groove, the gap width should be set to 0mm.
It is difficult to maintain the connection, and it is necessary to establish a construction method on the premise that such a gap will occur. The defects that occur when the above-mentioned groove gap occurs are board-like defects due to insufficient molten steel, and to prevent this, it is necessary to replenish the insufficient molten steel by adding filler wire. As described above, it is essential to supply filler wire when carrying out large-scale thick-walled structures using electron beam welding, and there is a need to establish a method for supplying it. However, there are almost no examples of welding in the horizontal or text position, or in the case of thick plate welding even in the downward position. The reason for this is that when the bead is placed horizontally or in the text orientation, molten steel drips from the bead surface, making it impossible to evenly supply the filler wire to the entire area in the thickness direction, and the relative relationship between the wire and the electron beam. This is because the positional relationship is severely restricted and the allowable range is extremely narrow. For practical use of electron beam welding, it is desired to improve the above points and establish a stable method for supplying filler wire. Next, to explain the above points with drawings, the points 1a and l
In figure b, when there is a groove gap 1 between the materials to be welded 11 and 12, the beam diameter of the electron beam 2 is small, so the weld line 3
A sufficient bead width is ensured by swinging the beam in the direction 8 orthogonal to the welding line, but in this way the beam irradiation area becomes short in the welding line direction and long in the orthogonal direction,
In this case, if the beam is deflected in the direction of the weld line due to mechanical fluctuations or residual magnetism, for example, the 2a and 2b
As shown in the figure, when the distance 5 between the filler wire 4 and the beam 2 is long, the beam does not hit the wire and the wire is not melted, while when it is short, the material to be welded 11
The beam hits the wire on the surface of , 12, and dripping occurs in horizontal and text orientations. The permissible range of variation in the distance between the wire and the beam is about ±O, 5 wLm, which is an extremely severe value in actual welding work. Note that 6 is the welding direction and T is the molten steel. The reason why such a tight tolerance is required is that the irradiation range of the beam in the direction of the weld line is narrow, and although increasing the beam diameter increases this range, the energy density decreases and the required It is difficult to adopt this method because penetration cannot be achieved and normal welding cannot be performed. In view of the current situation, the present invention aims to change the amplitude in the welding line direction from 0.2 to the diameter of the Wyra wire while swinging the electron beam both in the direction of the welding line and in the direction perpendicular to the welding line.
It is an object of the present invention to provide an electron beam welding method that eliminates the drawbacks of the prior art by performing welding while maintaining 2.5 times.

Next, embodiments of this invention will be explained with reference to the drawings.
In FIG. 3a, welding is performed while the electron beam 2 is oscillated by a deflection coil 10 in both the welding line direction 9 and the direction perpendicular to the welding line 8, and the shape of the oscillation in both directions is shown in FIG. 3b. Oval Aa with a long axis in the direction perpendicular to the welding line direction 9 shown, Oval Abl with a long axis in the welding line direction 9 Regular circle B1 Rectangle Cal with a long side in the welding line direction 9 It may be either a rectangle Cbl or a square D with long sides in the orthogonal direction, thereby widening the permissible range of the relative position of the filler wire 4 and the electron beam 2, and the permissible variation range of the distance between them, for example. When the beam vibration length in the welding line direction is 1.5 m1L, it can be extended to ±1.5 m1, making it possible to stably supply filler wire.

The reason for this is that the irradiation range of the beam in the direction of the welding line has increased, making it possible to sufficiently melt the wire even if the distance between the filler wire and the beam becomes longer, and conversely, even if the distance between the filler wire and the beam becomes shorter, the beam irradiation This is because the lower perforation is large enough to absorb the wire, preventing molten steel from dripping from the bead surface. Note that the swing width in the direction perpendicular to the weld line is determined by the conditions for sufficiently melting the groove gap, and there is an upper limit to the swing width in the weld line direction in horizontal and downward positions. If the drilled hole becomes too large, the retention of molten steel becomes unstable and welding defects occur.
This upper limit is 2.5 times the wire diameter (maximum 4.5 mm), and if the beam is swung in the direction of the welding line in a horizontal position beyond the upper limit, molten steel will clearly drip from the bead surface. At the same time, in order to obtain the beam oscillation effect in the weld line direction, there is a lower limit and a vibration amplitude of at least 02 times the wire diameter is required. Next, to describe an example of the method related to this development, if a groove gap of 2.0 mm is provided on a steel plate with a thickness of 100 mm and the electron beam is first swung only in the direction perpendicular to the welding line, the surface bead will be A large defect occurred due to the unmelted filler wire in the middle, and a large defect also occurred at the back bead because no back wave was formed due to the unmelted wire. When welding was performed by shaking the beads to give them the oscillating shapes of both elliptical shapes Aa and Ab shown in FIG. 3b, both the front and back beads exhibited a stable shape in appearance.

[Brief explanation of the drawing]

Figures 1a and 1b are explanatory front and plan views showing the conventional electron beam welding method, Figures 2a and 2b are side sectional explanatory views showing welding situations of backward welding and forward welding, respectively, and Figure 3a is FIG. 3B is a perspective view for explaining the method according to the embodiment of the present invention, and FIG. 3B is a plane trajectory diagram showing an example of the swinging shape of the electron beam. 1... Groove gap, 2... Electron beam,
3... Welding wire, 4... Filler wire,
5... Filler wire, distance between electron beams, 6.
...Welding direction, 7... Molten steel, 8...
...Welding line orthogonal direction, 9...Welding line direction, 10
... Deflection coil, 11, 12 ... Material to be welded.

Claims (1)

[Claims] 1 While swinging the electron beam in both the same direction and perpendicular direction to the welding line, the amplitude in the welding line direction is maintained at 0.2 to 2.5 times the diameter of the filler wire to be added (maximum 4.5 mm). An electron beam welding method characterized by: