JPH04279289A - Butt welding method - Google Patents

Abstract

PURPOSE:To furnish a welding method where a weld zone is finished flatly and finely without burn through of the weld zone even when thin sheet base metals are abutted on each other and welded together. CONSTITUTION:This is the butt welding method where a butt part of the base metals 1 abutted on each other is irradiated with a welding beam 4 and the base metals are welded together. An irradiation angle theta1 of the welding beam 4 for the base metals 1 and an inclined angle thetaG of the base metals 1 are held in the specified ranges to perform welding.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt welding method for butt welding base materials together using a laser beam or an electron beam.

0002

[Prior Art] Conventionally, when butt welding base materials using a laser beam or an electron beam, for example, as shown in FIG.
And as shown in FIG. 6, the base materials 1 and 2 are butted against each other,
While moving at a constant speed in the horizontal direction indicated by the arrow,
A welding beam 4 such as a laser beam or an electron beam is applied along the abutting portion 3 of the base materials 1 and 2 by a force of gravity G that is approximately perpendicular to the direction of movement.
The base metals 1 and 2 were butt welded by irradiating the base metals 1 and 2 from a direction parallel to the .

In this way, by irradiating the welding beam from a direction substantially perpendicular to the direction of movement of the base metal, energy can be concentrated in a minute area of the weld zone, and deep penetration can be achieved with less beam power. This is because there are advantages such as

0004

[Problems to be Solved by the Invention] By the way, in this welding method, since the penetration in the molten part is deep as described above, as the thickness of the base metal becomes thinner, the molten part of the base material escapes to the back side, and the back side There were problems such as poor bead shape on the side, uneven thickness of the welded part along the welding direction, and slight unevenness on the back side of the welded part. Further, if this condition progresses further, the molten part of the base material melts down to the back side, causing problems such as holes being formed in the welded part.

The present invention has been made in view of the above points, and even when butt welding thin base metals, there is no burn-through of the molten part, and the welded part is flat and beautifully finished. The purpose is to provide a butt welding method.

[0006]

[Means and operations for solving the problems] In order to achieve the above object, the present invention provides butt welding in which a welding beam is irradiated along the abutting portion of base materials that are butted together to weld the base materials together. In the method, the welding is performed while maintaining the irradiation angle of the welding beam with respect to the base material and the inclination angle of the base material within predetermined ranges.

The present invention is characterized in that welding is performed while maintaining the irradiation angle of the welding beam and the inclination angle of the base material within predetermined ranges. According to the method of the present invention, the thickness of the base metal as seen from the welding beam becomes relatively thick, and the non-melted part supports the molten part of the base material melted by the irradiation of the welding beam, and the molten part of the base metal receives the molten part. The effect of gravity can be weakened, making it possible to perform butt welding without the molten part coming off on the back side.

Here, in this specification, the irradiation angle of the welding beam refers to the relative angle of the base material 1 as shown in FIG. 1, including when moving the base metal side and when moving the welding beam source. When the direction of movement is indicated by a two-dot chain line, base material 1
The angle θI formed by the welding beam 4 and the welding beam 4 at the irradiation point I is defined as the angle θI formed by the welding beam 4 at the irradiation point I, and the inclination angle of the base material 1 is defined as the angle θG formed between the direction of relative movement and the gravity G.

In the method of the present invention, as shown in FIG. 2, when the inclination angle θG of the base material is 0 to 45°, the irradiation angle θI is set to 45 to 70°. Preferably, the irradiation angle θI is 45 to 60°. On the other hand, as shown in FIG. 1, when the inclination angle θG of the base material is 45 to 135°, the irradiation angle θI is set to 20 to 70°. Preferably the irradiation angle θI is 30 to 60 degrees, more preferably 40 to 5
Set to 0°.

If the irradiation angle θI is larger than 70°, it is not preferable because the penetration in the fusion zone becomes deep as in the conventional method, and it becomes difficult to align the welding beam with the abutting section. Further, if the irradiation angle θI becomes small, the welding beam cannot be uniformly irradiated onto the butt portion of the base materials to be butt welded, resulting in a problem that the fused portion becomes non-uniform.

[0011] As the welding beam, an electron beam or a laser beam is used. Electron beams are preferable because they have a very deep penetration compared to the width of the weld, and unlike electron beams, laser beams can be used in the atmosphere, have very strong light focusing, and have high energy density. This is more preferable in this respect. Various laser beams can be used, such as a YAG laser and a carbon dioxide laser, but in the case of butt welding metal materials, a YAG laser is preferable because the shorter wavelength has a higher energy absorption rate. Furthermore, a pulsed light source is preferable as the laser light because it does not waste heat and does not cause the temperature of the base material to rise more than necessary.

[0012] As the material for the base material, metal, especially aluminum with excellent thermal conductivity, is preferable, but it can also be used for high-temperature superconductors, and when the welding beam is a laser beam, non-metallic materials, For example, it can also be used for ceramics.

[0013]

Embodiment An embodiment of the present invention will be described in detail below with reference to FIGS. 3 and 4. FIG. 3 is a schematic configuration diagram of a laser welder that implements the method of the present invention. At the same time, the base materials 1 and 2 are butt-welded to each other and moved in the direction of the arrow in the figure, while shielding the molten part by ejecting shielding gas (inert gas) from the gas nozzle 12.

In this embodiment, base materials 1 and 2 to be welded
As shown in Fig. 4, aluminum plates with a thickness of 0.3 mm are butted together in a horizontal state (the inclination angle θG of base materials 1 and 2 is
= 90°), and butt welding was performed by irradiating pulsed light from a YAG laser onto the butt portion 3 such that the irradiation angle θI of the laser beam 11 was 45°. The welding conditions in this laser welder were as follows.

Focal length of condenser lens 10
120mm (irradiation at focal position) Laser beam 1
1 diameter 30mm
Peak power of laser beam 11
2kW (average power 150W) Laser beam 11
Pulse width: 5msec
frequency
15Hz (number of pulses per second) Diameter D of gas nozzle 12 (see Figure 3)
6mm shield gas
Argon gas shielding gas flow rate 30
l/min Distance L from the tip of nozzle 12 to abutment 3 (see Figure 3)
5mm Welding length of butt part 3
As a result of butt welding the base metals 1 and 2 under welding conditions where the moving speed of the base metals 1 and 2 was 130 mm/min or more, no burn-through of the molten portion of the base metals 1 and 2 occurred.

For comparison with the above example, the thickness was 0.3 m.
m aluminum plates are butted horizontally, and the irradiation angle θ is
When I was set to 90° and welding was performed for 30 cm along the abutting portion 3, dropouts occurred at three fused portions, and the thickness of the welded portion along the welding direction was non-uniform. In the above example, butt welding was performed by fixing the welding beam side and moving the base material along the welding direction of the butt portion. However, on the contrary, it goes without saying that welding may be performed by moving the welding beam side along the welding direction of the butt portion.

[0017]

As is clear from the above explanation, according to the present invention, butt welding is performed while maintaining the irradiation angle of the welding beam to the base metal and the inclination angle of the base metal within a predetermined range, so that thin-walled base metals can be welded. Even when butt welding materials, it is possible to obtain a uniform welded part with little burn-through, and it is possible to obtain a welded part with a good finish.

[Brief explanation of the drawing]

FIG. 1 is a side view illustrating the method of the present invention and showing the relationship with the irradiation angle of a welding beam when the inclination angle of the base material is 45 to 135 degrees.

FIG. 2 is a side view showing the relationship with the irradiation angle of the welding beam when the inclination angle of the base material is 0 to 45 degrees.

FIG. 3 is a schematic configuration diagram of a laser welder for butt welding base materials.

FIG. 4 is a side view showing the relationship between the inclination angle of the base material and the irradiation angle of the welding beam in FIG. 3;

FIG. 5 is a plan view showing a conventional butt welding method.

FIG. 6 is a side view of FIG. 5;

[Explanation of symbols]

1, 2 Base material 3 Butt part 4 Welding beam θI Irradiation angle of welding beam θG　　　　　　　　　Inclination angle of base material

Claims (7)

[Claims] 1. A butt welding method in which a welding beam is irradiated along the abutting portion of base metals that are butted together to weld the base metals, wherein the irradiation angle of the welding beam with respect to the base metal and the inclination of the base metal are A butt welding method characterized by welding while maintaining the angle within a predetermined range. 2. When the inclination angle is 0 to 45 degrees,
The butt welding method according to claim 1, wherein the irradiation angle is 45 to 70 degrees. 3. The butt welding method according to claim 1, wherein when the inclination angle is 45 to 135 degrees, the irradiation angle is 20 to 70 degrees. 4. The welding beam is an electron beam.
The butt welding method according to claim 1. 5. The butt welding method according to claim 1, wherein the welding beam is a laser beam. 6. Claim 1, wherein the base material is a metal material.
Butt welding method as described. 7. The metal material is aluminum.
The butt welding method according to claim 6.