JP3457289B2 - Thick plate welding method by combination of laser welding and TIG welding or MIG welding - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a welding target plate thickness of 5
The thickness is 0 to 100 mm, the deformation amount due to welding is extremely strict, and the accessible space is very narrow. Therefore, it is possible to secure a space for arranging welding equipment and perform secondary machining after welding. An object of the present invention is to provide a welding method capable of reducing the amount of deformation as much as possible and maintaining a high welding strength in a difficult place.

[0002]

2. Description of the Related Art Of the various welding methods that have been conventionally performed,
First, the non-consumable electrode type TIG welding method has a high controllability of the welding process and can select a wide range of filler rod materials even for materials sensitive to oxidation and nitriding. Has the advantage of being relatively easy to obtain.

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

Further, laser beam welding utilizing light energy has an advantage that high precision welding can be carried out because it has an extremely good converging property and can form a minute 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 or lateral) due to welding is performed even when welding with a narrow groove is performed. ) And angular distortion,
There is a problem that the predetermined dimension cannot be maintained and that the structural member is subjected to excessive stress (which contributes to the occurrence of cracks during use) due to the deformation.

FIGS. 8 to 9 show an example of the state of the objects to be welded when the blanket module of the fusion reactor and the rear wall are joined only by TIG or MIG arc welding. FIG. It is a figure explaining the direction of the vertical contraction and horizontal contraction which arise as a result. FIG. 9 is a diagram for explaining a state in which a rotational deviation occurs due to angular deformation. The thicker side of the welding layer contracts more greatly, causing angular deformations θ ₁ and θ _{2 in} the support legs of the blanket module, resulting in an X-shaped deformation. is doing.

Further, the welding time becomes longer as the size of the object to be welded becomes longer, and particularly in TIG welding, in order to ensure the quality of the welded portion, the welding heat input amount is often limited,
It has a disadvantage that it is not suitable for high speed and high efficiency welding.

On the other hand, when only the laser welding method is used, when a thick plate to be welded is to be laser-welded, a high-power laser oscillator is required, and even if a high-power laser oscillator is developed, it will be 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 the welding quality is unstable as compared with arc welding such as TIG and MIG. is doing.

The present invention has been made in view of the above circumstances, and provides a welding method which, while having an extremely simple structure, improves welding efficiency, minimizes the amount of deformation, and maintains a high welding strength. The purpose is to do.

[0010]

The above objects are achieved by the laser welding and the TIG welding or the M welding described in the claims.
This is achieved by a thick plate welding method in combination with IG welding. That is, (1) the welding deformation tolerance is extremely strict, the plate thickness to be joined is as thick as 50 to 100 mm, and the accessible space is very narrow, like the connection between the blanket module of the fusion reactor and the rear wall. The welding method is used in a place where there is not enough space for arranging the welding equipment, shortening of welding time is required, and it is difficult to perform secondary machining such as surface finishing after welding. The groove of the part is butt shaped, the root interval of the groove is 0.2 mm or less, the height of the root face is 50 mm or less, a laser welding torch is inserted in the root part, and the kind of laser is used especially in the narrow part. Depending on the requirement, irradiate a laser beam using an optical fiber, a mirror, etc.
Laser welding and TIG that perform welding with a small deformation associated with welding and insert a TIG welding torch or MIG welding torch at the groove portion other than the root portion to perform welding with high welding strength
Thick plate welding method in combination with welding or MIG welding.

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

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

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

[0014]

1 to 4 are views showing a first embodiment of a thick plate welding method according to the present invention. FIG. 1 shows a blanket module of a fusion reactor joined to a rear wall. Sectional drawing explaining the state of the space near a junction part, FIGS.
FIG. 2 is a partially enlarged view for explaining a state in each joining step of the portion 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 showing a root portion of the groove when welded by a laser beam. FIG. 4 is a diagram illustrating a state, and 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 and 4 formed in respective shapes. The plate thickness of the support legs 3 and 4 is 50 to 100 mm.
The continuous length of one leg (the direction perpendicular to the paper surface in FIG. 1) is about 1000 mm.

Various pipes are installed in the space surrounded by the back surface of the blanket module 1 and the supporting legs 3 formed therein, and the rear wall 2 and the supporting legs 4 formed therein.
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 thereof.

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 rear wall 2 and the rear wall 2 to perform welding. However, the cross section of the welding access space 6 is as narrow as about 100 to 150 mm square, so that the welding tools are arranged. Is not sufficiently secured, and there is a restriction that the welded part can be approached only from one side.

Under these circumstances, in order to join the support leg 3 and the support leg 4, the groove of the welded portion is first formed into a Y-shaped butted shape as shown in FIG. The spacing (narrow spacing) 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 weld the support leg 3 and the support leg 4. At this time, if it is difficult to bring the laser welding torch sufficiently close to the predetermined welded 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 removed, the TIG welding torch or the MIG welding torch is inserted, and the blanket module 1 is formed by multi-layer welding. The joining of the provided support leg 3 and the support leg 4 formed on the rear wall 2 is completed.

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

When welding for supporting the blanket module 1 of the fusion reactor as shown in FIG. 1 on the rear wall 2, when the plurality of support legs 3 and 4 are not simultaneously joined, the blanket module 1 is Since there is a risk of rotational displacement due to angular deformation, the support legs 3 and 4 formed on the blanket module 1 and the rear wall 2 should always be symmetrical with respect to the blanket module 1 at the same time. It is necessary to join.

FIGS. 5 to 7 are views for explaining the second embodiment. Unlike the fusion reactor blanket support leg, there is no restriction that the welded portion is welded only from one side, and the plates to be joined are joined together. If welding can be performed from both sides of the groove, make the shape of the groove a double Y shape as shown in FIG.
As shown in FIG. 6, a laser beam is irradiated from both sides of the plate by a laser torch to perform root welding.

Next, the remaining portion is joined by multi-layer welding by the TIG welding torch or the MIG welding torch, so that the welding time is shortened even when the plate thickness to be joined exceeds 100 mm and the deformation amount is suppressed and high accuracy is achieved. It is possible to obtain a joint having high strength.

In addition, even in the case of an I-shaped butted shape in which the joints are simply butted without forming the above-described groove at the joined portion, the deep portion of the joined portion is welded by the irradiation of the laser beam to form the outer surface of the plate. By joining the portion near to by TIG welding or MIG welding, the time is shortened and the welding deformation is small as in the above.
It is possible to obtain a welded portion having high reliability and high strength.

[0026]

As described above, according to the present invention, as described in the above embodiment, the following effects can be obtained. When joining thick plates with a plate thickness of 50 to 100 mm,
A narrow route of 0.2 mm or less is formed, and the route is precisely irradiated with a laser beam having a good condensing property and a high energy density, and the remaining portion near the surface of the bonding target plate is TIG, MI.
By performing multi-layer welding with an arc of G or the like, it is possible to extremely reduce shrinkage due to welding even when the equipment for welding is inserted and the cross-sectional area of the working space is as narrow as 100 to 150 mm square. It is possible to provide high-quality welding having high welding strength, and to provide welding that is sufficiently adaptable even when installing a fusion reactor blanket that requires high dimensional accuracy and reliability.

By making it applicable within the performance range of a laser beam welding machine which has been generally used in the past, it is possible to achieve the object with extremely low equipment cost and simple structure without requiring special equipment. It will be possible to achieve.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention, illustrating a state of a space near a joint portion 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 starting welding of a portion in FIG.

FIG. 3 is a diagram showing a state where the root portion of the groove of FIG. 2 is welded and joined by a laser beam.

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

FIG. 5 is a view showing the state of the groove of the double Y-shaped butted shape according to the second embodiment of the present invention.

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

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

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]

1 Blanket module 2 Rear wall 3, 4 Support leg 5 Welding part 6 Welding space 7 Welding access space 7 Route 8 Welding part by laser 9 Welding part by TIG welding or MIG welding 10 Joining member 11 Laser beam θ ₁ , θ ₂ angular deformation

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B23K 9/167 B23K 9/167 A 9/173 9/173 A G21B 1/00 G21B 1/00 CN (72) Inventor Sato Shinichi 1 801 Mukaiyama, Naka-machi, Naka-gun, Naka-gun, Ibaraki Prefecture 1 Inside the Naka Institute of the Japan Atomic Energy Research Institute (72) Inventor Kensuke Mohri 2-6-5 Minamisuna, Koto-ku, Tokyo Kawasaki Heavy Industries, Ltd. Tokyo Design Office (56) Reference References JP-A 2002-273587 (JP, A) JP-A 6-114587 (JP, A) JP-A 61-17388 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B23K 9 / 00,9 / 16 B23K 26/00-26/42 G21B 1/00

Claims (4)

(57) [Claims] 1. The allowable amount of welding deformation is very strict, the plate thickness to be joined is as thick as 50 to 100 mm, and the accessible space is very narrow, as in the connection between the blanket module and the rear wall of a fusion reactor. A welding method in a place where there is insufficient space for arranging the welding equipment, shortening of welding time is required, and it is difficult to perform secondary machining such as surface finishing after welding. The groove of the part is butt shaped, the root interval of the groove is 0.2 mm or less, the height of the root face is 50 mm or less, the laser welding torch is inserted in the root part, and the laser type is used especially in the narrow part. Depending on the situation, a laser beam is used in combination with an optical fiber, a mirror, etc. to perform welding with a small deformation associated with welding, and the groove portion other than the root portion has a TIG welding torch or MI.
A thick plate welding method using a combination of laser welding and TIG welding or MIG welding, characterized in that a G welding torch is inserted to perform welding with high welding strength. 2. The laser welding and TIG welding or MI 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 thick plate welding method 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 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.