JPS59232690A - Welding method - Google Patents

Abstract

PURPOSE:To perform welding with high quality without reinforcement of weld and lack of penetration in the stage of welding circular shaped members such as pipes by welding simultaneously the joint part of both members with a heat source of high energy density such as laser from the outside circumferential side of said part and with an arc heat source from the inside circumferential side. CONSTITUTION:A high energy density beam such as a laser beam or electron beam is irradiated via a beam bender 4 and a condenser lens 5 to the butt joint part of pipes 1a, 1b from the outside circumferential side of said part to form a weld zone 7 except about 2mm. unwelded part on the inside circumferential side in the stage of butting and welding the pipes at the end faces. A weld zone 8 is formed at the same time with a TIG welding torch 6 from the inside circumferential side of the joint part so as to overlap on the unwelded part and about 1mm. welded part 7. Welding is performed in this case by rotating the pipes 1a, 1b around the central axis while holding the laser and the torch 6 immobile. The weld zone which is free from reinforcement of weld and lack of penetration on the inside circumferential side and does not require finish working is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a welding method, and particularly to a bath welding method for welding cylindrical members such as pipes, tanks, and flanges.

[Technical background of the invention and its problems]

Conventionally, when welding pipes, tanks, flanges, etc., as shown in FIG.

A groove is provided on the outer circumferential side of the joint portion 1b, and this groove portion is welded using an arc heat source such as TIG or plasma. As another method, as shown in FIG. 2, there is a method in which grooves are provided on the outer and circumferential sides of the joining portion of the flange 2 and the pipe 1, respectively, and arc M welding is performed.

In the above-described welding method, weld metal often protrudes as excess on the outer and inner circumferential sides of each welded portion 3°3. When a normal pipe or the like is used, there is a problem in that the flow of the fluid is disturbed by the excess portion of the extra layer on the inner circumferential surface of the bamboo due to the flow of fluid inside. Therefore, it has the disadvantage that the excess fi'lS on the inner circumferential surface must be smoothed by machining after welding. As shown in Figure 41, it is extremely difficult in terms of welding technology to weld the first layer to create extra buildup all around the inner circumferential surface.
Since the welding layer is formed over many layers, the amount of molten metal increases, and defects such as 7-tanisaka cracks are likely to occur, making it difficult to process after welding. It also has

In addition, in recent years, arc (instead of contact, laser and
11. Means for welding using a high energy density heat source with a child beam of less than 4° has come into widespread use. As shown in Figure 3, such welding with a laser or the like is carried out by irradiating the joint between the pipes la and lb with a laser or 14 beam from the outer circumferential side (in the direction of the arrow in the figure). In order to carry out penetration melting of the pipe wall thickness, 17. rrm
:', 4 degrees of overfill will occur. Therefore, it has the disadvantage that it is necessary to finish this excess portion smoothly at the welding end stage. It also has the disadvantage that if the height of the extra heap is selected to reduce the height of the overfill, partial filling may be insufficient and bath contact defects are likely to occur.

Furthermore, in laser or electron beam welding, the weld penetration is 11 times due to lightning, so if the direction of the laser or electron beam is slightly distorted, as shown in Figure 4, the pipe la. , Ib also has the disadvantage that the inner periphery i1+11 of the JQ joint portion is not welded.

There is no problem as long as the direction of the concubine beam and the direction of the concubine @171 above are exactly the same, but 'J'!i
'71! It is extremely difficult to move up a large river because a high 7th grade of +0.1 to 0.2 is lowered.

[Purpose of the invention]

The present invention has been made in consideration of the above-mentioned drawbacks, and it is an object of the present invention to provide a bath method 11 that can reduce the need for finishing force finishing after welding and also eliminate welding defects before the bath is insufficiently filled. It is something.

[Summary of the invention]

In order to achieve the above object, the welding method of the present invention is a welding method for joining pipes, tanks, and flange-attached members having a circular shape.・Undissolved 92 on the inner circumference side of the above-mentioned joint part due to
While welding so as to leave a portion intact, weld the arc y, on the inner circumference of the above-mentioned joint. ? Depending on the source, the welding process is performed using a high-energy density heat source.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 5 to 10.

FIG. 5 shows an embodiment of the present invention, in which the end faces of two pipes la and Ib are brought together, and a laser is irradiated from the outer circumferential side of this joined part as an energy density heat source in this embodiment. It is done like this.

The above laser is generated by a laser oscillator (not shown) such as a carbon dioxide laser oscillator, and after being reflected by a beam bender 4, it passes through a condensing lens 5 and passes through pipes la, l.
The joint portion b is irradiated from a direction perpendicular to the central axis of the pipe. Also, inside the pipe la, TIG
? WJN torch 6 has its tip connected to the pipes la and l above.
It is provided so as to be oriented toward the inner peripheral side of the joint portion b.

In this embodiment, laser welding is performed from the outer periphery of the joint between the pipes la and lb, and this welding is performed so as to leave about two or less unwelded parts on the inner periphery of the joint. Then, from the inner peripheral side of the above joint part,
TtGmw is performed with a TIG welding torch 6, and in this case, the bath welding depth is determined by the laser mentioned above ('I contact part 7 is reached, and both bath contact R1 (minute 7,
8 l mm-') 41 ships, 14-IA will be set up to match each other.

At this time, when the pipes 5 are placed in the double row 5, the pipes la and lb are configured to rotate continuously about their central axes, so that the bath welding can be performed without moving the laser and the bath welding torch 6. being done.

Therefore, in the above actual situation 1, there is 1 pipe.

Since there is almost no excess on the inner periphery of the joint part of 1b, the finishing of the bath joint is done by machining 7;, 1: <
Furthermore, the joint portion between the two vibrators 1a and 1b does not remain unwelded, and stable quality can be achieved.

In addition, the tip 4' + fal
Since the TIG welding bath welding part 8 is used as a hot spring, it is possible to eliminate tri+N defects such as blow poles and cold shuts that tend to occur in the welding part of the laser bath welding.

FIG. 6 shows another W! of the present invention. 7M example, the joint surface of one pipe 1b is provided with a retaining protrusion 8i59 formed by extending the inner peripheral edge of this pipe 1b in the axial direction, and the joint surface of the other pipe 1a is provided with the above-mentioned engagement protrusion 8i59. A notched stepped portion 1.0 that engages with the mating protrusion 9 is provided. The retaining protrusion 9 has a wall thickness of 0.5 to 2 m+a, and a protrusion length of 0.2 to 1
You can set it in between. Then'C1 above engaging protrusion glS9
Insert the main stand into the notch step 10. C1 both vibrators la
, lb are joined.

In addition, arrow A in the figure is the welding direction of the laser, and arrow B is TlG.
This shows the d welding method, and the above implementation ρ
Similarly to the above, laser welding is performed from the outer periphery of the pipes la and lb, and TIG welding is also performed from il on the inner periphery. At this time, the welded portion 7 by laser bath welding is connected to the engaging protrusion 9 and the notched step 1.
Conditions are set so that the welding area 8 reaches the part where the 0 and 0 engage with each other, and the conditions are also set so that the bath welding part 8 by T welding and G welding is one process opposite to the laser welding part 7.

Therefore, in this embodiment, it may be possible to leave unwelded parts for the pipes la and l, as in the case of the bow of the embodiment 19.
The rest of the inner circumferential surface of the joint part b can be welded without difficulty. Furthermore, since both the vibrators la and lb are joined by engaging the engaging protrusion 9 and the notch step 10, the pipes la and l
It is easy to maintain the joint of b, and moreover, it can be joined accurately. In this case, TIGI′l from the inner circumferential side of the pipe
In the -+ contact, since the bath has a wide width, even if the engaging protrusion 9 and the notch step 1.0 are provided, insufficient melting and unwelded portions will not occur.

FIG. 7 shows another embodiment of the present invention, in which the pipe 1
An example is shown in which the flange 2 is joined to one end of the flange 2.

The joint part of the flange 2 has a stepped part 11 that engages with the pipe 1.
The pipe 1 and the flange 2 are joined by engaging the end of the pipe 1 with the stepped portion 11.

Then, in the same manner as in the above-mentioned valley welding and ρ welding, laser welding is performed from the arrow A direction and TIG welding is performed from the arrow B direction. At this time, the laser beam is emitted at an angle of about 1° (τ), and the appropriate irradiation angle is approximately 5° to 20° for practical purposes.For example, if the wall thickness of the pipe 1 is 9 mm, , when the height difference of the stepped portion 11 is Q, 5 mm, the irradiation angle is set to about 5°.

In this embodiment as well, there is no excess buildup in the inner circumferential direction of the vibrator, and the welding is performed without contacting the pipe 1 and the flange 2. And it can be done accurately.

FIG. 8 shows still another embodiment of the present invention, in which the fitted inner circumference r, d f of the flange 2 is the same as the wall thickness of the pipe 1] and extends in the direction of the pipe 1. Joint part 1 that comes out
2, and a cutout step 10 and an engaging protrusion 9 are provided on the y-crystal plane of the fitting portion 12 and on the end of the pipe 1, respectively, similar to the embodiment shown in FIG. , being helpful.

In this embodiment, the flange 2 and the pipe 1 are brought into alignment by engaging the notch step ↓0 with the engaging protrusion 9, and welding is performed by laser from the direction of the arrow A, and at the same time TIG welding is performed from this direction.

Therefore, similar to the above embodiment, it is possible to perform welding with a small amount of excess welding, and even if the flange 2 and the pipe 1 are welded together, it can be performed in the same way as 67 J'1 between vibrators. This makes welding work easier, and the stress flux in the flange 2 portion can be reduced.

In addition, FIG. 9 shows another -Ab lees example of the present invention, in which a V-shaped notch 13° 13 between kJi is formed on the outer periphery 613 and the inner periphery of the joint portion of both pipes Ia and lb, respectively.
is provided, and this cut portion 13 has an angle of 0°2 to 1,0°.
It has a depth of mmg degrees, and may have a box-like shape.

In this embodiment, the incisions 13 are made at the wide positions ii'j of the pipes la and lb when it is easy to hatch the pipes 9 for overnight hatching.
This makes it easier to detect with sensors such as the original sensor,
It is possible to prevent the welding position from shifting during automatic welding. Furthermore, the cutout portion 13 can further reduce the amount of bulging.

Furthermore, FIG. 10 shows another embodiment of the present invention, in which the addition is omitted, and on the outside of the joint portion of the pipes la and lb, there is a V having a depth of less than % of the wall thickness of the pipes. Letter-shaped bevel 14
In addition, a cutout step 10 and an engaging protrusion 9 are provided on the inner circumferential side, respectively, similar to the embodiment shown in FIG. In this embodiment, bath contact is performed with a laser from the direction of arrow A, and 'I' from the direction of arrow B.
After welding both pipes la and lb by performing an IG bath, a bead 15 is welded to the tip 14 while supplying a filler wire to a laser heat source.

Therefore, it becomes possible to perform bath welding of thick pipes with thick (metal) El-, and laser welding is performed on BH
This is suitable when using an oscillator whose output is less than IQ mm.

In each of the above embodiments, a laser is used as the energy density heat source. However, other means such as a laser beam may be used, and arc melting (
Although we have only explained the case using TIG welding, it is of course possible to obtain the same effect by means such as plasma.

〔Effect of the invention〕

As described above, in the fj4 method according to the present invention, a high-energy heat source is applied from the outer circumferential side of the joint portion of the cylindrical member so as to leave an unwelded portion on the inner circumferential side, and
Since welding is performed from the inner circumferential side of the joint part using an arc heat source to the welding part caused by the high energy heat storage heat absorption source, the remaining 151L of the joint part, welding, and inaccuracies are removed. As a result, 1'&3
It is possible to perform quality and safe welding without any problems. Furthermore, the excess build-up remaining on the inner circumferential surface can be significantly reduced by 100%, resulting in less finish kneading/maruing after bath welding.

4. Figures 1 and 2 are longitudinal cross-sectional views of a portion of the bath exposed to a conventional arc heat source, and Figures 3 and 4 are partial longitudinal cross-sectional views of a conventional laser bath. Please do not show discipline! Figure 6, Funeral Figure 7, ■
FIGS. 8, 9, and 10 are diagrams showing a portion of Aψ[1v, respectively, showing an embodiment of the present invention.

1... Pipe, 2... Flange, 3, 7.8...
Welding part, 4... Beam bender, 5... Condensing lens, 6... TIG welding torch, 9... Engaging protrusion, 10...
...Notch step, 11...Step, 12...Touching 8 groups, J3
...Notch 1-1I1114...Bevel, 15...Bead.

Claims (1)

[Claims] In a welding method for joining members having a cylindrical shape such as pipes, tanks, flanges, etc., welding is performed from the outer periphery of the joining part of the above members using a high energy density heat source so as to leave an unwelded part on the inner periphery of the joining part. Also, a welding method characterized in that welding is carried out from the inner peripheral side of the joint part to the part to be welded by the high energy density heat source using an arc heat source.