JPH08155649A - Electrode for large input heat submerged welding and power supply method - Google Patents

Abstract

PURPOSE: To obtain stable high speed welding capable of eliminating short circuit and wire clogging in a nozzle in large input heat submerged arc welding. CONSTITUTION: A power supply point 3 is arranged at 50-100mm above the tip end 2A of contact tip and is connected to a torch 5 through an insulating body 8. A cabtire cable 7 is connected to the power supply point 3 through a L shape insulating jig 4 and power is supplied while the upper part of insulating jig 4 is held through supporting part at the upper part of torch 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high heat input submerged arc welding electrode used for steel frames, bridges, steel plates for shipbuilding, etc., and a power feeding method.

[0002]

2. Description of the Related Art A conventional power supply method for submerged arc welding is 3 from the tip of a contact tip (hereinafter referred to as a tip).
It is connected to the cabtire cable and torch at the top of 00-600mm.

[0003]

In the case of large heat input welding such as box column corner joint welding, since a large current is used, the wire is fed at high speed, so that the welding wire short-circuits with the work piece and is temporarily fixed. I have something to do. In this case, since the conventional power feeding method is 300 mm above the tip, the welding wire 1 and the torch 5 are placed inside the torch 5 as shown in the sectional view of the torch in FIG.
However, there is a problem that a short circuit easily occurs and a seizure wire feeding failure easily occurs. In the figure, 2 is a contact chip, 3 is a feeding point,
7 is a cabtire cable.

An object of the present invention is to eliminate short circuit in the nozzle in large heat input submerged arc welding, eliminate wire clogging, and realize stable high-speed welding.

[0005]

DISCLOSURE OF THE INVENTION The present invention is to solve the above problems, and in the submerged arc welding electrode, the feeding point is 50 to 100 m from the tip of the contact tip.
m upper part, the power feeding point is connected to the torch through an insulator, the power feeding point is connected to an L-shaped power feeding insulating jig having a cabtire cable passage, and the upper portion of the insulating jig is It is an electrode for large heat input submerged arc welding, characterized in that it is held on the upper part of the torch via a support part. In addition, in the power feeding method for submerged arc welding, the power feeding point is 50 to 50
100 mm above, the feeding point is connected to the torch via an insulator, the cabtire cable is connected to the feeding point through an L-shaped feeding insulating jig, and the upper portion of the insulating jig is the upper portion of the torch. Is a power supply method for large heat input submerged arc welding, which is characterized in that power is supplied while being held via the support part. Here, the feeding point means a contact point between the torch and the cabtire cable.

[0006]

The present invention will be described below with reference to the drawings. FIG. 2 is a front view of the high heat input submerged arc welding electrode of the present invention, and FIG. 1 is a sectional view thereof. Connect the feeding point 3 connected to the lower end of the torch 5 through the insulator 8 from the tip 2A of the tip 2 to
The position is 0 to 100 mm above. As a result, even if the welding wire 1 fed at high speed is short-circuited with the object to be welded and temporarily fixed, the welding wire 1 and the torch 5 are insulated by the insulator 8 in the torch 5, so that Even if they come into contact with each other, short-circuiting does not occur, and good wire feeding can be obtained. If the distance L between the feeding point and the tip of the tip is less than 50 mm, the radiant heat during welding is significantly increased, which adversely affects the durability of the cabtire cable and the like. If it is larger than 100 mm, the same phenomenon as a short circuit between the welding wire and the torch, which is a problem of the conventional welding electrode, may occur.

The feeding point 3 is connected to an L-shaped feeding insulating jig 4, and the upper portion of the feeding insulating jig 4 is held on the upper portion of the torch 5 via a supporting portion 6, and By passing the cabtire cable 7 inside the tool 4, radiant heat from the plate is prevented, and by holding the cabtire cable 7 via the support portion 6, contact with the torch 5 is prevented.

The material of the insulator 8 is phenol resin,
Insulating resins such as fluororesins and ceramics such as alumina, zirconia and silica can be used. The method of connecting the power feeding nozzle 5 and the power feeding point 3 via the insulator 8 is the method of using the insulator 8 of the same type as the torch shown in FIGS. 1 and 2, or the insulator on the thread surface shown in FIG. 9 and the like.

The material of the L-shaped power supply insulating jig 4 can be insulating resin such as phenol resin, fluorine resin, etc., and ceramics such as alumina, zirconia, silica, etc. The length in the direction is preferably 30 to 100 mm, and the length in the vertical direction is preferably 50 to 500 mm.

The material of the supporting portion 6 may be an insulating resin such as phenol resin or fluorine resin, or ceramics such as alumina, zirconia or silica. The shape is not particularly limited, but as shown in FIG. 5, for example. A two-divided semi-cylindrical jig in which both ends are bolted can be used.

[0011]

EXAMPLE A power feeding tip of the present invention was used as shown in FIGS. 1 and 2, the feeding point was at a distance of 50 mm from the tip of the tip, the insulating method was as shown in these figures, and the material was alumina. As a comparative example, the one shown in FIG. 3 was used, and the feeding point was 300 mm from the tip of the chip.

A base material 10 of SM490B steel having a groove shape shown in FIG. 6 (plate thickness: 60 mm, groove angle: 30 °, root face: 2 mm, length: 3000 mm) is applied to JIS Z.
Iron powder bond flux (particle size 12 × 100 mesh) corresponding to FS-BT1 specified in 3352 and JIS Z
Welding was performed in combination with a YS-S1 corresponding wire (wire diameter 6.4 mm) defined by 3351. The welding conditions are 2 electrodes, welding heat input is 519600 J / cm, L pole (leading electrode) 2100A 42V, T pole (trailing electrode) 1
The welding speed is 20 cm / min at 700 A and 50 V.
Table 1 shows the welding results.

[0013]

[Table 1]

In Table 1, the bead appearance ◯ means that the bead surface is smooth without any undercuts or slag inclusions on the bead surface, and x means that the bead surface is rough because all of the above welding defects occur on the bead surface. It is a thing. In the present invention, a weld metal having a good bead appearance with no wire clogging during high current welding and with little voltage fluctuation was obtained.

[0015]

As described above, according to the present invention, it is possible to prevent the wire from short-circuiting in the torch. Therefore, it is possible to obtain a weld metal having a good bead appearance without the wire clogging during high current welding.

[Brief description of drawings]

FIG. 1 is a sectional view of a welding electrode of the present invention.

FIG. 2 is a front view of the welding electrode of the present invention.

FIG. 3 is a sectional view of a conventional welding electrode.

FIG. 4 is a sectional view showing another example of an insulator according to the present invention.

FIG. 5 is a cross-sectional view of a supporting portion according to the present invention.

FIG. 6 is a cross-sectional view showing a groove shape of a test piece used in Examples.

[Explanation of symbols]

 1 Welding wire 2 Contact tip 2A Tip of contact tip 3 Feeding point 4 Insulation jig for feeding 5 Torch 6 Support 7 Cabtyre cable 8, 9 Insulator

Claims (2)

[Claims] 1. An electrode for submerged arc welding, comprising:
The power feeding point is located 50 to 100 mm above the tip of the contact tip, the power feeding point is connected to the torch via an insulator, and the power feeding point is connected to an L-shaped power insulating jig having a cabtire cable passage. An electrode for large heat input submerged arc welding, wherein an upper portion of the insulating jig is held on an upper portion of the torch via a supporting portion. 2. A power feeding method for submerged arc welding, wherein the power feeding point is 50 to 50 mm from the tip of the contact tip.
100 mm above, the feeding point is connected to the torch via an insulator, the cabtire cable is connected to the feeding point through an L-shaped feeding insulating jig, and the upper portion of the insulating jig is the upper portion of the torch. A power feeding method for large heat input submerged arc welding, which is characterized in that power is fed while being held via a support portion of the.