JPH10216972A - Composite welding method of laser and consumable electrode arc - Google Patents

Abstract

(57) [Problem] To provide a composite welding method of laser and arc capable of high-speed welding of a thick plate. SOLUTION: On a welding route 6 of plate materials 1 and 2 to be welded,
The laser processing nozzle 3, the plasma torch 4, and the assist gas injection nozzle 5 are arranged. The leading part is a laser and the trailing part is an arc, the distance between the laser irradiation position a and the target position b of the welding wire of the arc is set to an appropriate value, and the gap between the welding routes of the plate materials 1 and 2 is set to 10% of the plate thickness. As described above, welding is performed with the laser beam diameter set to be equal to or smaller than the laser beam diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of welding by combining an arc heat source and a laser, and more particularly to a method of performing butt welding of a thick plate.

[0002]

2. Description of the Related Art A laser beam can be freely converged by an optical device and has a high energy density. Therefore, it is considered to be one of the excellent thermal processing means. Output lasers are still large and expensive. In contrast, arc welding is inexpensive and relatively easy to handle, but is inferior to lasers in deep penetration and high speed welding performance.

[0003] In recent years, a method combining arc welding and laser welding has been attempted.
No. 484. This method is intended to stabilize the arc by plasma generated at the time of laser welding and to obtain a good weld.

[0004]

However, according to the method described in the above publication, butt welding of a thin plate having a sheet pressure of up to several mm can be performed, but butt welding of a thick plate cannot be performed. As described above, conventionally, a welding method for combining an arc heat source and a laser has been proposed, but a high-speed welding method for a thick plate, which is practically required, has not yet been elucidated and proposed. .

An object of the present invention is to solve the above-mentioned problems and to provide a method for performing butt welding of a thick plate having a thickness of 10 mm or more at a high speed.

[0006]

SUMMARY OF THE INVENTION The present inventors have concluded that a welding method for combining arc welding and laser welding has not yet been sufficiently elucidated on its effective method and high-speed welding performance of a medium-thick plate. As a result of intensive research, laser and arc welding can be superimposed, resulting in deep penetration of the laser and the deposited metal of the arc, enabling efficient welding and increasing the root gap If you can deeply penetrate the root of the groove,
It has been found that high-speed welding of thick plates is possible even with a relatively low-power laser. By setting an appropriate route gap and selecting the distance between the laser irradiation position and the target position of the welding wire of the arc, it has been found that high-speed welding of thick plates can be effectively performed by effectively combining arc welding and laser welding. And formed the present invention.

That is, a welding method according to claim 1 is a butt welding method using a combination of a laser 3 and a consumable electrode arc 4, wherein the leading and succeeding electrodes are the laser 3 and the consumable electrode arc 4, respectively. 2 is characterized in that the root gap along the welding line 6 is set in a range of 10% or more of the plate thickness of the workpieces 1 and 2 and the diameter of the laser beam or less.

According to a second aspect of the present invention, in the method of the first aspect, the distance L between the laser irradiation position a and the target position b of the consumable electrode type arc welding wire is set in a range of 1 mm to 7 mm. It is characterized by the following.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of a welding apparatus for carrying out the method of the present invention. Reference numerals 1 and 2 denote plate materials to be welded, each of which is set horizontally on a welding jig (not shown) so that the corresponding end faces are close to each other. A laser processing nozzle 3, a welding torch 4, and an assist gas (for example, helium) injection nozzle 5 are arranged on a welding line 6 of the plate material to be welded.

The laser processing nozzle 3 is supported upright on the welding line 6. The welding torch 4 is supported in a tilted posture after being raised by about 60 ° from the plane of the plate materials 1 and 2 on the welding line 6, and the arc of the welding torch 4 with respect to the laser beam irradiation position a. The target position “b” of the welding wire is arranged rearward in the welding direction. Then, the injection nozzle 5 of the assist gas that is injected toward the irradiation position a of the laser beam is inclined forward by about 45 ° from the plane of the plate materials 1 and 2 on the welding route 6 ahead of the laser processing nozzle 3. It is arranged in a posture.

In the present invention, it is important to provide a root gap in the welding line 6 without bringing the end faces of the plates 1 and 2 into close contact with each other.
It is preferable to set the thickness between 10% and less than the laser beam diameter of the plate thickness of No. 2. Then, the preceding is a laser and the following is a consumable electrode type arc, and the welding proceeds. Further, it is necessary to set the distance L between the laser beam irradiation position a and the target position b of the arc welding wire within a range of 1 mm to 7 mm. Further, the plates 1 and 2 to be welded are provided with a groove having a groove cross section of not more than a wire melting volume per unit welding line obtained by consumable electrode type arc welding.

In the conventional welding method with a root gap of 0 mm, in order to form deep penetration of laser,
Since a large amount of heat is required, the use of a very expensive high power laser exceeding 20 kW was indispensable. In contrast,
Under the above welding conditions of the present invention, by setting the root gap to an appropriate value, a beam hole is already formed, a deep penetration can be ensured with a low-power laser, and the deposited metal from the consumable electrode type arc can be secured. Accordingly, the root gap and the groove can be filled with the weld metal, and the welding speed of the thick plate can be increased.

[0013]

EXAMPLES The welding method of the present invention was tested as follows.

(Experimental conditions) Plate material to be welded, thickness: 16 mmt, groove, depth: 6 mm,
Angle 30 ° Root gallop 0 to 0.6mm Laser output 7kw Welding speed 3m / min Assist gas flow rate 20l / min (He) Arc heat input condition 250Ax30v Welding wire 1.2mmΦ (YGW12) Laser beam irradiation position and welding wire target position Distance from 1mm to 7mm

(Experimental Results) FIG. 2 shows the relationship between the root gap of the groove and the penetration depth obtained in the above experiment. According to this figure, it is recognized that the penetration depth is greatly increased by setting an appropriate root gap. This is because when the root gap is 0 mm, the amount of heat input per unit welding line for forming the laser beam beam hole deeply is insufficient, and the penetration depth becomes shallow, whereas by taking the root gap, The beam hole is already formed and can be melted to the deep part, and if the root gap is too large compared to the laser beam diameter, the laser will not be able to melt the groove root part It is shown that.

FIG. 3 shows a cross section of a typical laser arc weld obtained from the above results. This figure shows a welding speed of 2 m / min, a laser output of 7 kw, and an assist gas flow rate of 30 liter / min.
(He), the welding was performed under the conditions of arc welding conditions of 450 Ax30 V (wire diameter 1.6 mmΦ). In this case,
It was able to penetrate to a depth of 15.5 mm.

[0017]

As described above, according to the present invention,
By setting the root gap between the sheets to be welded from 10% or less of the sheet thickness to the laser beam diameter or less, the beam hole is already formed, and it is possible to secure deep penetration even with a low-power laser and to consume. The root gap portion and the groove portion can be filled with the weld metal by the weld metal from the electrode-type arc, and the welding speed of the thick plate butt can be increased.

Further, by setting the laser irradiation position and the target position of the arc welding wire to appropriate values, an arc stabilizing action of plasma generated at the time of laser welding works even at the time of high-speed welding, so that a good welded portion can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an arrangement of a welding apparatus for carrying out the method of the present invention.

FIG. 2 is a graph showing a relationship between a root gap and a penetration depth.

FIG. 3 is a sectional view showing a state of a butt weld.

[Explanation of symbols]

 Reference numerals 1, 2 Welded plate material 3 Laser processing nozzle 4 Plasma torch 5 Assist gas injection nozzle 6 Welding route a Laser beam irradiation position b Target position of welding wire

Claims (2)

[Claims] In a butt welding method using a combination of a laser and a consumable electrode arc, a laser is used as a leading part and a consumable electrode type as a following part, and a root gap along a welding line of the plate to be welded is set to a plate of the plate to be welded. A composite welding method of a laser and a consumable electrode arc, characterized in that the thickness is set within a range of not less than 10% of the thickness and not more than the diameter of the laser beam. 2. The combined laser and consumable electrode arc according to claim 1, wherein the distance between the laser irradiation position and the target position of the consumable electrode type arc welding wire is set in a range of 1 mm to 7 mm. Welding method.