JP2002301582A - Thick plate welding method by combination of laser welding and tig welding or mig welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method which makes a deformation rate as small as possible and maintains high welding strength. SOLUTION: Combined welding of inserting a laser welding torch into a root zone, irradiating the narrow zone in particular with the laser beam which makes combination use of an optical fiber, mirror, etc., is accordance with the kinds of the laser to perform welding which is little in the deformation accompanying the welding, and welding a groove exclusive of the root zone is performed by inserting a TIG welding torch or MIG welding torch in combination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for welding a plate having a thickness of 5
Because it is 0-100 mm thick, the allowable amount of deformation due to welding is extremely strict, and the accessible space is very narrow, it is necessary to secure space for placing welding equipment and perform secondary machining after welding. It is an object of the present invention to provide a welding method in which a deformation amount is reduced as much as possible in a difficult place and a high welding strength is maintained.

[0002]

2. Description of the Related Art Among various conventional welding methods,
First, the non-consumable electrode type TIG welding method has high controllability of the welding process and a wide selection of filler rod materials even for materials that are sensitive to oxidation and nitridation. Is relatively easy to obtain.

[0003] Next, in the consumable electrode type MIG welding method, the shielding gas is appropriately selected to change the arc generation state and the thermal properties to control the heat input of the welding, so that the joining member butt portion is formed. By inserting a thin nozzle into the root portion (narrow gap) to perform multi-layer building, there is an advantage that welding can be performed with high efficiency, low heat input, and a narrow heat-affected zone.

[0004] Further, laser beam welding utilizing light energy has an advantage of being capable of performing high-precision welding because it has a very good light-collecting property and can form a very small spot having a very large energy density. ing.

[0005]

However, among the above-mentioned conventional techniques, when only arc welding such as TIG or MIG is used, shrinkage (longitudinal and horizontal) due to welding can be performed even when welding with a narrow groove is performed. ) And angular deformation
There is a problem that a predetermined dimension cannot be maintained, and that excessive stress (contributing to crack generation during use) is applied to the structural member due to deformation.

FIGS. 8 and 9 show an example of a state of an object to be welded when a blanket module and a rear wall of a fusion reactor are joined only by TIG or MIG arc welding. FIG. FIG. 4 is a diagram illustrating directions of vertical contraction and horizontal contraction that occur. FIG. 9 is a view for explaining the state of occurrence of rotational displacement due to angular deformation. When the thick side of the weld layer contracts more, angular deformations θ ₁ and θ ₂ are generated in the support legs of the blanket module, and the X-shaped deformation occurs. are doing.

In addition, the welding time increases as the size of the workpiece increases, and in particular, in TIG welding, the amount of heat input is often limited in order to ensure the quality of the welded portion.
It has the disadvantage that it is not suitable for high-speed, high-efficiency welding.

On the other hand, when only the laser welding method is used, a high-output laser oscillator is required when welding a thick plate to be welded with a laser, and even if a high-output laser oscillator is developed, it is very difficult. In addition to being expensive, there is a possibility that defects such as porosity and undercut may occur in the welded portion as shown in FIG. 10, and there is a problem that the welding quality is unstable compared to arc welding such as TIG and MIG. are doing.

The present invention has been made in view of such circumstances, and provides a welding method that has a very simple structure, improves welding efficiency, minimizes deformation, and maintains high welding strength. It is intended to be.

[0010]

SUMMARY OF THE INVENTION The above objects are attained by laser welding and TIG welding or MIG welding as described in the appended claims.
This is achieved by a thick plate welding method in combination with IG welding. (1) Like the connection between the blanket module and the rear wall of the fusion reactor, the allowable amount of welding deformation is extremely strict, the plate thickness to be joined is as thick as 50 to 100 mm, and the accessible space is very narrow. A welding method in a place where there is not enough space for disposing welding equipment, a reduction in welding time is required, and it is difficult to perform secondary machining such as surface finishing after welding. The groove of the part has a butt shape, the root interval of the groove is 0.2 mm or less, the height of the root surface is kept at 50 mm or less, and the laser welding torch is inserted in the root part. Irradiate a laser beam using an optical fiber, a mirror, etc., according to
Laser welding which performs welding with small deformation due to welding, inserts a TIG welding torch or MIG welding torch into the groove other than the root, and performs welding with high welding strength.
Thick plate welding method by welding or combination with MIG welding.

(2) Laser welding and TIG welding or MIG according to (1), wherein the groove of the joint has a Y-shaped butt shape.
Thick plate welding method in combination with welding.

(3) A method for welding a thick plate by a combination of laser welding and TIG welding or MIG welding according to (1), wherein the groove of the joint has a double Y-shaped butt shape.

(4) Laser welding and TIG welding or MIG according to (1), wherein the groove of the joint has an I-shaped butt shape.
This is a thick plate welding method in combination with welding.

[0014]

1 to 4 show a first embodiment of a thick plate welding method according to the present invention. FIG. 1 shows a method for joining a blanket module of a fusion reactor to a rear wall. FIG. 2 is a cross-sectional view illustrating the state of the space near the joint, and FIGS.
2 is a partially enlarged view illustrating a state in each joining step of the part a in FIG. 2, FIG. 2 is a view showing a state of a groove before welding is started, and FIG. 3 is a view when a root portion of the groove is welded by a laser beam. FIG. 4 is a diagram illustrating a state when the remaining portion of the groove is joined by TIG welding or MIG welding.

The blanket module 1 of the fusion reactor is supported by the rear wall 2, which is usually carried out by welding the supporting legs 3, 4 formed respectively. The thickness of the support legs 3 and 4 is 50 to 100 mm
The continuous length of one leg (in the direction perpendicular to the paper of FIG. 1) is about 1000 mm.

In the space surrounded by the back surface of the blanket module 1 and the supporting legs 3 formed thereon, and the rear wall 2 and the supporting legs 4 formed thereon, various piping and
The wiring is inserted and arranged in a complicated manner, and it is difficult to dispose a welding tool for joining the support leg 3 and the support leg 4 in the space.

Therefore, in order to join the blanket module 1 and the rear wall 2, the gap between the adjacent blanket modules 1, or the supporting legs 3, 4 communicating with the gap.
It is necessary to insert a welding tool from the welding access space 6 formed by the back wall 2 and perform welding, but the cross section of the welding access space 6 is as narrow as about 100 to 150 mm square. Space is not sufficiently ensured, and only one side of the welded portion can approach.

In order to join the support leg 3 and the support leg 4 under such a situation, first, the groove of the welded portion is made to have a Y-shaped butt shape as shown in FIG. The interval (narrow interval) is 0.2 mm or less, the height of the root surface is 50 mm or less, and the remaining portion is formed in a V-shape.

Next, a laser welding torch is inserted into the welding access space 6, and the route 7 is irradiated with, for example, a CO ₂ laser beam to perform welding with the support legs 3 and 4. At this time, when it is difficult to bring the laser welding torch sufficiently close to the predetermined welding portion, a laser beam is irradiated using an optical fiber or a mirror to perform sufficient welding.

After confirming that the welding of the route 7 is completely completed as shown in FIG. 3, the laser welding torch is pulled out, a TIG welding torch or a MIG welding torch is inserted, and the blanket module 1 is formed by multi-layer welding. The joining of the support legs 3 provided and the support legs 4 formed on the rear wall 2 is completed.

With this, the groove route is welded in a short time with a laser beam having a good light-collecting property and a very high energy density, with high precision, with the amount of deformation suppressed as much as possible, and the remaining portion is subjected to TIG. Welding or MIG
By joining by welding, it is possible to perform welding with high strength without causing problems such as porosity remaining inside or forming an undercut on the finished surface.

When welding is performed to support the blanket module 1 of the fusion reactor as shown in FIG. 1 on the rear wall 2, if the plurality of support legs 3 and 4 are not joined at the same time, the blanket module 1 Since there is a possibility that rotational displacement due to angular deformation may occur, the support legs 3, 4 formed on the blanket module 1 and the rear wall 2, respectively, are always selected to be symmetrical with respect to the blanket module 1 and simultaneously. It is necessary to join.

FIGS. 5 to 7 are views for explaining the second embodiment, in which there is no restriction that the welded portion is welded only from one side, as in the fusion reactor blanket support leg, and the plate to be welded is not limited. When it is possible to perform welding from both sides of the groove, the shape of the groove is a double Y shape as shown in FIG.
As shown in FIG. 6, a laser beam is radiated from both sides of the plate by a laser torch, and the root is welded and joined.

Next, the remaining portion is joined by multi-layer welding using a TIG welding torch or a MIG welding torch, thereby shortening the welding time even when the thickness of the plate to be joined exceeds 100 mm, achieving high accuracy with reduced deformation. A high strength joint can be obtained.

In addition, even in the case of an I-shaped butt shape where the joints are merely joined without forming the above-mentioned groove at the joint, the deep portion of the joint is welded by laser beam irradiation, and the outer surface of the plate is welded. By joining the parts close to by TIG welding or MIG welding, the time is reduced and the welding deformation is reduced, as described above.
It is possible to obtain a highly reliable and high strength weld.

[0026]

As described above, according to the present invention, the following effects can be obtained as described in the above embodiment. When joining a thick plate with a plate thickness of 50 to 100 mm,
A narrow route of 0.2 mm or less is formed, and a laser beam having a good light-collecting property and a high energy density is precisely applied to the route, and a portion close to the surface of the remaining plate to be joined is TIG, MI
By performing multi-layer welding with an arc such as G, insertion of equipment for welding, even in a place where the cross-sectional area of the space of the operating part is as small as 100 to 150 mm square, while significantly reducing shrinkage due to welding, In addition, it is possible to perform high-quality welding with high welding strength, and to provide a welding that can be sufficiently adapted even when mounting a fusion reactor blanket requiring high dimensional accuracy and reliability.

Since the laser beam welding machine can be applied within the range of the performance of a laser beam welding machine generally used in the past, the purpose can be achieved by extremely low equipment cost and a simple configuration without special equipment. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment according to the present invention and illustrating a state of a space near a joint when a blanket module of a fusion reactor is joined to a rear wall.

FIG. 2 is a view showing a state of a groove of a Y-shaped butt shape before welding of a portion a in FIG. 1 is started.

FIG. 3 is a view showing a state in which a groove root portion in FIG. 2 is welded and joined by a laser beam.

FIG. 4 is a diagram illustrating a state in which portions other than the root portion of the groove in FIG. 2 are joined by TIG welding or MIG welding.

FIG. 5 is a diagram showing a double Y-shaped butted groove in a second embodiment according to the present invention.

FIG. 6 is a diagram showing a state where the groove root portion of FIG. 5 is welded and joined by a laser beam.

FIG. 7 is a diagram illustrating a state where portions other than the root portion of the groove in FIG. 5 are joined by TIG welding or MIG welding.

FIG. 8 is a diagram showing an example of a conventional technique.

FIG. 9 is a diagram showing an example of a conventional technique.

FIG. 10 is a diagram showing an example of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Blanket module 2 Rear wall 3, 4 Support leg 5 Weld part 6 Weld access space 7 Route 8 Weld part by laser 9 Weld part by TIG welding or MIG welding 10 Joint member 11 Laser beam θ ₁ , θ ₂ angle deformation

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B23K 9/167 B23K 9/167 A 9/173 9/173 A 26/08 26/08 K G21B 1/00 G21B 1 / 00 N (72) Inventor Mikio Enoe, 801 Mukaiyama, Naka-cho, Naka-machi, Naka-gun, Ibaraki Pref. Inside the Japan Atomic Energy Research Institute Naka Research Laboratory Laboratory Naka Research Laboratory (72) Inventor Kensuke Mohri 2-6-5 Minamisuna, Koto-ku, Tokyo Kawasaki Heavy Industries, Ltd. Tokyo Design Office F-term (reference) 4E001 AA03 BB07 BB08 BB12 CC04 4E068 AA01 BC01 BE00 BE03 DA00 4E081 YS10 YX20

Claims (4)

[Claims] 1. Like a connection portion between a blanket module and a rear wall of a fusion reactor, the allowable amount of welding deformation is extremely strict, the plate thickness to be joined is as large as 50 to 100 mm, and the accessible space is very narrow. A welding method in a place where the space for welding equipment is not sufficient, a reduction in welding time is required, and it is difficult to perform secondary machining such as surface finishing after welding. The gap of the groove is abutted, the root interval of the groove is 0.2mm or less, the height of the root surface is 50mm or less, and the laser welding torch is inserted in the root part. A laser beam is irradiated using an optical fiber, a mirror, or the like in accordance with the conditions, and welding with small deformation due to welding is performed.
A thick plate welding method using a combination of laser welding and TIG welding or MIG welding, wherein a welding with high welding strength is performed by inserting a G welding torch. 2. The laser welding and TIG welding or MI welding according to claim 1, wherein the groove of the joint has a Y-shaped butt shape.
Thick plate welding method in combination with G welding. 3. The method for welding a thick plate by a combination of laser welding and TIG welding or MIG welding according to claim 1, wherein the groove of the joint has a double Y-shaped butt shape. 4. The laser welding and TIG welding or MI welding according to claim 1, wherein the groove of the joint has an I-shaped butt shape.
Thick plate welding method in combination with G welding.