JP2002219585A - Structures and repair methods - Google Patents

Abstract

(57) [Abstract] (with correction) [PROBLEMS] A structure composed of iron, nickel or their respective alloys and weld metal with damage such as cracks on the surface due to aging, etc. Secondary damage such as cracks does not occur due to the work to repair the damage, and furthermore, the metal structure change and new residual stress of the base metal near the damage caused by the work are suppressed as much as possible, and the same as before the damage was introduced. Provided is a structure having a degree of soundness or higher and a repair method for restoring the aforementioned state. A jig is provided near a damaged portion of a structure made of iron, nickel, or an alloy thereof, and a weld metal, and has a damaged surface portion.
Metallic bonding of the pad 12 after removing the damaged portion or the damaged portion by the friction stir welding method while supporting the load due to the insertion of the metal, and returning the structure to a sound state equal to or more than that before the damage was introduced. Features.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure having a damaged surface portion and a method for repairing the structure.

[0002]

2. Description of the Related Art Materials constituting structures such as nuclear power plants, thermal power plants, and chemical plants may be damaged on the surface by prolonged exposure to a service environment. The use of these structures while leaving such damages leads to an increase in damage and, consequently, a reduction in the reliability of the structure.
Therefore, if damage is apparent on the surface of the structure, it is desirable to perform repair work promptly and return it to a state equal to or higher than that before the damage was introduced, so it is suitable for the condition of the part of the structure Various repair technologies are being developed.

[0003] As a method for relatively easily repairing damage introduced into the surface of a structure, TIG welding or laser welding using a welding material such as a filler wire is widely used. By using these, the surface of the damaged portion introduced can be overlaid to return to the same state as before the damage was introduced. However, if the repair work is to be performed reliably in a wider area in the thickness direction, depending on the construction conditions, it may be necessary to increase the amount of melting of the base metal relative to the amount of deposited metal, or to increase the number of overlay layers. And other problems. In addition, the melting of metal due to welding,
Through the solidification process, a thermal effect is given to the vicinity of the weld, and there is a concern that changes in the metal structure, deformation due to construction, or the generation of residual stress due to construction may be a factor for introducing new damage. You. In particular, in the repair work by welding to the reactor pressure vessel and the reactor internals containing helium by the (n, α) nuclear reaction due to neutron irradiation, heat input during welding It is known that when the temperature of the base material rises and its area is large, helium diffuses into the crystal grain boundaries to form bubbles and induces cracks due to a decrease in the strength of the grain boundaries. As a method for preventing repair welding cracking of helium-containing structural material as a result of neutron irradiation such as a reactor pressure vessel or a reactor internal structure, as described in JP-A-2000-2464, A method is disclosed in which the penetration depth is made as small as possible to reduce the thermal effect on the base material during construction. However, in the conventional repair method of damage using welding, since the penetration depth is small, when repairing damage such as a crack that has progressed to a deep region, a part of the crack near the very surface is welded. Therefore, most of the cracks remain and it is difficult to return the structure to a sound state equal to or higher than that before the damage was introduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure composed of iron, nickel or their respective alloys and weld metal, whose surface has been clearly damaged due to aging or the like. Secondary damage such as cracks does not occur due to the work for repairing the metal, and furthermore, the metal structure change and new residual stress of the base metal near the damage caused by the work are suppressed as much as possible, and it is about the same as before the damage was introduced. An object of the present invention is to provide a structure having soundness higher than that and a repair method for returning the structure to the above-mentioned state.

[0005]

In order to achieve the above object, according to the present invention, in a structure composed of iron, nickel or their respective alloys, and a weld metal, a structure near a damaged portion that has become apparent on a surface portion is provided. A jig is attached to the joint, and the damage is repaired by a friction stir welding method while supporting the load due to the insertion of the rotating tool.

Further, a groove is formed after removing the vicinity of a damaged portion which has become apparent on the surface portion, and a metal plate formed into a shape equivalent to the groove is fitted into the groove. A jig is attached to the base and the contact metal and the existing structural material are joined by friction stir welding while supporting the load caused by the insertion of the rotating tool.

Further, a groove is formed after removing the vicinity of the damaged portion that has become apparent on the surface portion, a metal plate having a shape equivalent to the groove is fitted, a jig is provided on the metal plate, and rotation is performed. Weld the entire contact metal and the existing structural material by friction stir welding while supporting the load due to the insertion of the tool. In friction stir welding using a rotating tool, friction heat and plastic flow cause
The damaged portion can be repaired without using a filler.

[0008] The repair performed on the structure may be friction stir welding to the surface of the structure having a flat surface or a curvature.

In the above structure, the repaired portion may be a reactor pressure vessel or a reactor internal structure composed of iron, nickel or their alloys and weld metals.

In the above structure, the portion to be repaired may be a structure composed of helium-containing iron, nickel or their respective alloys and weld metal.

In the above-mentioned structure, the portion to be repaired may be a structure composed of neutron-irradiated iron, nickel or their respective alloys and weld metal.

It is desirable that a rotating tool for obtaining the above-mentioned structure be made of a material having a hardness equivalent to Vickers hardness of 550 or more.

Further, the friction stir welding for obtaining the above-mentioned structure is performed in the coolant of air, inert gas or water, or in the vicinity of the joint while being forcibly cooled by the coolant. It is desirable to do.

[0014]

(Embodiment 1) FIG. 1 is a perspective view of a specimen having a slit simulating surface crack damage. The material of this test piece was three kinds of SUS304 austenitic stainless steel base material as an iron-based alloy, a welded metal of a welded joint obtained by TIG welding this with a Y308ULC filler wire, and SQV2A low alloy steel. As the nickel-based alloy, there were used two kinds of welded metal of a welded joint obtained by NAC600 corrosion-resistant and heat-resistant superalloy base metal and coated arc welding of the base metal with a DNiFeCr-1J welding rod. The shape of the test body 1 that simulates a structure is square, and its size is 30.
The slits were 150 mm in length and 0.2 mm in width, and the depths were 3 mm and 6 mm. Rotating the rotary tool 3 in the rotation direction 4 on the slit 2 and performing friction stir welding while moving to the broken arrow 5 indicating the construction direction,
The slit portion was metallically joined. The rotating tool 3 used here is made of a metal or ceramic having a Vickers hardness equivalent to Vickers hardness of 550 or more, such as a cemented carbide, which is harder than the structure simulation specimen 1, and is rotated as necessary. A surface modification treatment has been applied to improve workability such as seizure resistance of the tool. The shape of the rotary tool is such that a pin is attached to a cylindrical shaft having a bottom diameter of about 10 mm. The shoulder part was adhered to the surface of the member for construction. The work in this embodiment was performed at room temperature and in the atmosphere at a tool rotation speed of 1300 rpm and a welding speed of 150 mm / min.

FIG. 2 is an enlarged cross-sectional view of the vicinity of the working portion after friction stir welding has been performed in the atmosphere on the test specimen of the SUS304 austenitic stainless steel base material according to the procedure shown in FIG. Before the construction, a slit 2 having a depth of 3 mm provided to the cross section of the test specimen 1 was observed. As shown in FIG. 1, the construction direction was changed while rotating the rotating tool 3 in the rotation direction 4. The friction stir welding performed along the dashed arrow 5 shown in the drawing causes frictional heat generated by the contact between the rotating tool 3 and the test piece 1 and a plastic flow phenomenon. As a result, the slit 2 is joined, sealed, and has a smooth surface. A part could be formed. When the metal structure was observed in detail by optical microscopy, the joint 6 formed a metal structure that had undergone plastic flow and subsequent cooling, and a heat-affected zone having a width of 0.1 mm or less was formed around the joint. Was observed. Further, no joint defect was observed in the joint 6 and the heat-affected zone 7 by this construction.

In particular, when these materials are used as a reactor pressure vessel or a reactor internal structure, neutron irradiation (n,
α) It is known that helium is generated by a nuclear reaction, and it is known that these heliums are aggregated by heat input by welding or the like and cause welding cracks inherently observed in neutron irradiation materials. Therefore, in this embodiment,
In addition to the stainless steel base material (SUS304), stainless steel weld metal (Y308LULC), low alloy steel base material (SQV2A), nickel base alloy base material (NFC600) and nickel base alloy weld metal (DNiFeCr- The soundness of the construction part was evaluated using the test specimens using the five types of 1J), and helium-containing test specimens in which helium was preliminarily injected at 10 appm by ion irradiation were also prepared, and the soundness was evaluated. Table 1 summarizes the results of the condition of the test specimen after the slit having a depth of 3 mm was constructed by the method shown in FIG. The symbols indicating the results are as follows.

◎: No defects such as cracks were found at the joint (weld) and in the vicinity, and no macroscopic deformation of the specimen was observed.… No defects such as cracks were found at the joint (weld) and in the vicinity. , The specimen is deformed △: Fine cracks are observed at and near the joint (weld), and the specimen is deformed ×: The joint (welding) cannot be performed

[0018]

[Table 1]

As shown in Table 1 (a), the slit of 3 mm depth was completely sealed by the friction stir welding according to the present invention, but the slit of 3 mm depth was sealed by welding according to the prior art. Since the heat input needs to be large, it is difficult to carry out the work, such as large deformation of the test specimen and fine weld defects. There is concern about the occurrence of stress. Furthermore, as shown in Table 1 (b), a sound joint without macroscopic deformation could be obtained by friction stir welding even on a test piece containing helium, but in the prior art, a slit having a depth of 3 mm was obtained. It is found that it is very difficult to search for appropriate conditions for sealing the steel, and it is not possible to avoid concerns about cracks, deformation of the test specimen, and occurrence of residual stress.

FIG. 3 is an enlarged view of the vicinity of the joint after performing friction stir welding on a 6 mm deep slit on a SUS304 austenitic stainless steel base material specimen under the same conditions as the construction shown in FIG. FIG. Friction heat and plasticity generated by the contact between the rotating tool 3 and the test piece 1 by performing the friction stir welding along the broken arrow 5 indicating the construction direction while rotating the rotating tool 3 in the rotating direction 4 as shown in FIG. As a result of the flow phenomenon, the slit was joined and sealed on the side closer to the surface, and a smooth surface portion could be formed. When the metal structure was observed in detail by optical microscopy, the joint 6 formed a metal structure that had undergone a plastic flow and a subsequent cooling process. Formation was observed. However, in the present embodiment, the unjoined slit 8 remains in the lower part of the joint 6, but at the boundary 9 between the unjoined slit 8 and the joint 6, cracks or the like that impair the soundness of the joint 6 are not generated. I couldn't see it.

In this example, as in the case shown in Table 1, test specimens having slits with a depth of 6 mm were prepared from five kinds of materials and subjected to the test. Helium-containing specimens in which helium was pre-injected by ion irradiation were also prepared, and their soundness was evaluated. Table 2 summarizes the results of the condition of the test specimen after the slit having a depth of 6 mm was constructed by the method shown in FIG. The symbols indicating the results conform to Table 1 above.

[0022]

[Table 2]

As shown in Table 2 (a), the slit of 6 mm depth is partially sealed by the friction stir welding according to the present invention, but the slit of the portion near the surface is completely sealed. Was done. On the other hand, with conventional welding, it is necessary to increase the heat input in order to seal the slit to the same depth as that obtained by friction stir welding. As can be seen, it can be seen that the construction is difficult. Furthermore, as shown in Table 2 (b), a sound joint without macroscopic deformation could be obtained by friction stir welding even for a helium-containing test specimen. It turns out that it is very difficult to avoid cracks and deformation of the test specimen. In addition, according to the joining according to the present invention, almost no deformation of the test body is observed, and therefore, it is expected that the residual stress in the vicinity of the joint generated by the restraint of the deformation in the structure is almost suppressed.

Example 2 FIG. 4 is a perspective view of a test piece simulating a state in which a damaged portion is removed from a structure having a crack on the surface to form a groove, and a simulated groove is formed on the surface. Is accompanied. The material of this test piece was three kinds of SUS304 austenitic stainless steel base material as an iron-based alloy, a welded metal of a welded joint obtained by TIG welding this with a Y308ULC filler wire, and SQV2A low alloy steel. Further, as the nickel-based alloy, there were used two types of welded metal of a welded joint obtained by NAC600 corrosion-resistant and heat-resistant superalloy base material and the coated base material obtained by coating and welding the same with a DNiFeCr-1J welding rod. The shape of the test body 10 that simulates a structure is square, and its size is 3
00 × 100 × 20mm, mock groove is 150m long
m, width 50 mm, depth 3 mm and depth 6 mm. Here, a metal plate 12 for the groove 11 is inserted from the same material as the material used for the test body 10. The rotating tool 3 is rotated in the rotation direction 4 along the boundary between the test piece 10 and the metal support 12, and friction stir welding is performed while moving the tool 10 to the dashed arrow 13 indicating the construction direction. Joined.

FIG. 5 shows that a groove 3 having a depth of 3 mm was formed on a specimen of a SUS304 austenitic stainless steel base material.
It is an enlarged view which shows the process which inserts the backing metal 12 made from SUS304 and joins the boundary by friction stir welding. Under the same conditions as for the slit 2 shown in FIG.
Friction stir welding was performed along the boundary on the surface of the test body 10 and the backing 12. Due to frictional heat generated by the rotating tool 3 and the plastic flow phenomenon, the joint 1
No. 5 was formed smoothly without any joint defects, including the surface portion. The metal structure of the joint 15 was equivalent to the observation result performed in FIG. However, although a part of the boundary 16 between the bottom butted portion of the backing metal 12 and the specimen remained unbonded, there was no tendency to impair the soundness of the joint 15 at the boundary 17.

As the material of the specimen, in addition to the stainless steel base material (SUS304), stainless steel weld metal (Y308LULC),
Low alloy steel base material (SQV2A), nickel base alloy base material (NF
C600) and nickel base alloy weld metal (DNiFeCr-1J)
The type was used. It is known that helium is generated by a (n, α) nuclear reaction by neutron irradiation, particularly when these materials are used as a reactor pressure vessel or a reactor internal structure. Has been known to aggregate and cause welding cracks inherent in neutron irradiated materials. Therefore, in the present example, a helium-containing test piece into which helium was preliminarily injected by ion irradiation was also prepared, and its soundness was evaluated. Table 3 summarizes the results of the condition of the test specimen after the 3 mm-deep plate was applied by the method shown in FIG.
The symbols indicating the results conform to Table 1 above.

[0027]

[Table 3]

As shown in Table 3 (a), the metal plate and the test piece having a depth of 3 mm by the friction stir welding according to the present invention do not have a vertical abutting portion and do not show macroscopic deformation with the test piece. Completely joined. Note that a part of the bottom butted portion remained unjoined, but did not affect the soundness of the joined portion.
On the other hand, in order to weld a 3mm-deep metal plate to a test piece by conventional welding, it is necessary to increase the heat input, so that the test piece is greatly deformed and fine welding defects are observed. It turns out that construction is difficult. Further, as shown in Table 3 (b), even with a helium-containing specimen, a sound joint without a macroscopic deformation could be obtained by friction stir welding. It can be seen that the search for appropriate conditions for welding gold is very difficult, and that cracking and deformation of the specimen cannot be avoided.
In addition, according to the joining according to the present invention, almost no deformation of the test body is observed, and therefore, it is expected that the residual stress in the vicinity of the joint generated by the restraint of the deformation in the structure is almost suppressed.

FIG. 6 shows that a groove having a depth of 6 mm was formed on a specimen of SUS304 austenitic stainless steel base material, and SUS3
It is an enlarged view which shows the process of inserting the backing plate 18 manufactured in 04 and joining the boundary by friction stir welding. Under the same conditions as those for the slit 2 shown in FIG. 1, friction stir welding was performed along the boundary on the surface of the test piece 10 and the metal plate 18. Due to the frictional heat generated by the rotating tool 3 and the plastic flow phenomenon, the joining portion 15 is
There was no joint defect, and the surface was formed smoothly including the surface portion. The metal structure of the joint 15 was equivalent to the observation result performed in FIG. However, although a part of the boundary between the longitudinal butting portion of the backing plate 18 and the test piece remained unbonded, there was no tendency to impair the soundness of the bonded part 15 at the boundary.

In this example, as shown in Table 3 above, test specimens were prepared from five kinds of materials and provided with a 6 mm deep metal plate. In addition, a helium-containing test specimen in which helium was pre-injected by ion irradiation was also prepared,
The soundness was evaluated. Table 4 summarizes the results of the condition of the test specimen after the 6 mm-deep metal plate was applied by the method shown in FIG. The symbols indicating the results conform to Table 1 above.

[0031]

[Table 4]

As shown in Table 4 (a), the friction stir welding according to the present invention leaves a part of the vertical butt portion at the deeper position and the bottom butt portion, but the 6 mm-deep abutment is located above the surface. The specimen was completely joined to the specimen at a depth of about 3 mm without any macroscopic deformation. On the other hand, 6 mm to the same depth as that obtained by friction stir welding by welding according to the prior art
It is necessary to increase the heat input in order to weld the metal plate of the depth to the specimen, so it is understood that the construction is difficult, such as large deformation of the specimen and small welding defects. . Further, as shown in Table 4 (b), a sound joint without a macroscopic deformation could be obtained by friction stir welding even for a test piece containing helium, but in the prior art, a contact having a depth of 3 mm was obtained. It can be seen that the search for appropriate conditions for welding gold is very difficult, and that cracking and deformation of the specimen cannot be avoided. Further, according to the joining according to the present invention, almost no deformation of the test specimen is observed, and therefore, it is expected that the residual stress in the vicinity of the joint generated by the restraint of the deformation in the structure is almost suppressed.

(Embodiment 3) FIG. 7 is along a broken line arrow 21 showing a working direction so that friction stir welding is performed on a specimen 10 and a pad 12 having the same shape as that of FIG. FIG. Under the same conditions as for the slit 2 shown in FIG.
It was constructed so as to overlap / 4. Rotation tool 3
Due to the frictional heat and plastic flow phenomenon caused by the above, the joining portion including the longitudinal butting portion and the bottom butting portion was formed smoothly without joining defects and including the surface portion. The metal structure of the joint formed by the construction was equivalent to the observation result performed in FIG. In addition, the interface between the bottom of the backing metal and the specimen, which was observed in the observation in FIG. 5 described above, was completely joined by applying the entire backing metal, and was not observed.

In this example, as in the case shown in Table 4 above, test specimens provided with a metal plate having a depth of 3 mm from five kinds of materials were prepared and subjected to the test. In addition, a helium-containing test specimen in which helium was pre-injected by ion irradiation was also prepared,
The soundness was evaluated. Table 5 summarizes the results of the condition of the test sample after the 3 mm-deep plate was applied by the method shown in FIG. The symbols indicating the results conform to Table 1 above.

[0035]

[Table 5]

As shown in Table 5 (a), due to the friction stir welding according to the present invention, the 3 mm-depth metal plate and the test piece did not remain in both the vertical butted portion and the bottom butted portion, and macroscopic deformation was observed. Completely joined. On the other hand, in order to weld a 3mm-deep metal plate to a test piece by conventional welding, it is necessary to increase the heat input, so that the test piece is greatly deformed and fine welding defects are observed. It turns out that construction is difficult. Further, as shown in Table 5 (b), a sound joint without a macroscopic deformation could be obtained by friction stir welding even for a helium-containing specimen, but in the prior art, a 3 mm deep contact was obtained. It can be seen that the search for appropriate conditions for welding gold is very difficult, and that cracking and deformation of the specimen cannot be avoided. In addition, according to the joining according to the present invention, almost no deformation of the test body is observed, and therefore, it is expected that the residual stress in the vicinity of the joint generated by the restraint of the deformation in the structure is almost suppressed.

Although the above-described embodiments were all performed in a natural cooling atmosphere in the atmosphere, air, an inert gas,
By forcibly cooling using a coolant such as water and increasing the cooling rate of the joint, a sounder joint can be formed.

[0038]

According to the present invention, the use of friction stir welding for repairing a structure having a crack or the like introduced on its surface minimizes the generation of residual stress during construction and ensures reliable repair. By sealing and joining the damage, it is possible to provide a structure having a sound repair site and a construction method. In particular, to provide an effective construction method for repairing structural materials such as reactor pressure vessels and reactor internals that contain helium due to neutron irradiation and that are likely to have welding cracks specific to neutron irradiated materials due to heat input be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the application of the present invention to crack-simulated slit sealing.

FIG. 2 is a sectional view showing a joint when the present invention is applied to a 3 mm deep slit seal.

FIG. 3 is a cross-sectional view showing a joint when the present invention is applied to a 6 mm deep slit seal.

FIG. 4 is a perspective view showing the application of the present invention to a metal plate joint.

FIG. 5 is a cross-sectional view showing a joint portion when the present invention is applied to the joining of four sides of a 3 mm deep metal plate.

FIG. 6 is a cross-sectional view showing a joint portion when the present invention is applied to the joining of four sides of a 6 mm deep metal plate.

FIG. 7 is a cross-sectional view showing a joint when the present invention is applied to the entire surface of a 3 mm-deep metal plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... The test piece which provided the slit which simulated the crack, 2 ... Slit, 3 ... Rotating tool, 4 ... Rotation direction, 5 ... Slit sealing working direction, 6 ... Slit sealing joint, 7 ... Heat effect Part, 8: Unjoined part with 6 mm depth slit, 9: Boundary part between joined part 6 and slit 2, 10: Specimen with groove after removal of crack, 11 ... Groove part, 12: Depth 3 mm buckle, 13… four-side joining direction of buckle, 14… test piece 1
Vertical boundary between 0 and backing plate 12, 15 ... backing plate joint, 16
... Bottom boundary between test piece 10 and backing plate 12, 17... Boundary between bonding portion 15 and bottom boundary 16, 18.
Reference numeral 19: a vertical boundary portion between the test piece 10 and the contact metal 18, 20: a boundary between the contact metal joining portion 15 and the vertical boundary portion 19, 21 ... a joining direction of the entire contact metal.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Doi 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuhisa Aono 7-1 Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Hisanobu Okamura 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. BM00 DA17 EA01 EB06

Claims (17)

[Claims] 1. A structure made of iron, nickel or an alloy thereof, and having a damaged portion evident on its surface, wherein the damaged portion is repaired by a friction stir welding method using a rotating tool. A structure characterized by being performed. 2. A structure made of iron, nickel, or an alloy of each of them, which has a damaged portion evident on its surface, is applied to a groove formed by removing the damaged portion. A structure wherein gold is inserted and the perimeter of the metal is metallically joined to the structure by a friction stir welding method using a rotating tool. 3. A structure made of iron, nickel, or an alloy thereof and having a damaged portion evident on a surface portion, wherein the structure is applied to a groove formed by removing the damaged portion. A structure wherein gold is fitted and the entire surface of the gold and the structure are metallically joined by a friction stir welding method using a rotating tool. 4. A reactor facility having a reactor pressure vessel or / and a reactor internal structure made of iron, nickel, or an alloy thereof, and having a damaged portion that is evident on its surface. A nuclear reactor facility wherein the damaged portion is repaired by a friction stir welding method using a rotating tool. 5. A reactor facility having a reactor pressure vessel and / or a reactor internal structure made of iron, nickel, or an alloy thereof, and having a damaged portion that becomes apparent on the surface. A metal plate is fitted into the groove formed by removing the damaged portion, and the perimeter of the metal is metallically joined to the structural material by a friction stir welding method using a rotating tool. Reactor equipment. 6. Reactor equipment having a reactor pressure vessel and / or a reactor internal structure made of iron, nickel or an alloy thereof, and having a damaged portion that is evident on the surface. A metal plate is fitted into a groove formed by removing the damaged portion, and the entire surface of the metal and the structural material are metallically joined by a friction stir welding method using a rotating tool. Nuclear reactor equipment. 7. A structure according to claim 1, wherein the surface of the structure having a flat surface or a curvature has a damaged portion which is repaired by friction stir welding. object. 8. A nuclear reactor facility according to claim 4, wherein the member having a damaged portion evident on its surface is made of iron, nickel, or an alloy thereof containing helium. Reactor equipment characterized by the following: 9. A nuclear reactor facility according to claim 4, wherein the member having a damaged portion evident on the surface is made of iron, nickel, or an alloy thereof each of which has been irradiated with neutrons. Reactor equipment characterized by the following: 10. A method for repairing a damaged portion having a surface portion which is made of iron, nickel, or an alloy thereof, wherein a rotating tool is inserted into the damaged portion. Repairing the damaged portion by frictional heat and plastic flow generated by the rotation of the structure. 11. A method for repairing a damaged portion having a surface portion which is made of iron, nickel or an alloy thereof, wherein a groove is formed after removing the damaged portion. A metal plate is fitted into the groove, a rotary tool is inserted into the interface between the metal and the structure, and the periphery of the gold is formed as a structure by friction heat and plastic flow generated by rotation of the rotary tool. A method for repairing a structure, characterized in that it is metallically joined. 12. A method for repairing a damaged portion having a surface portion which is made of iron, nickel or an alloy thereof, wherein a groove is formed after removing the damaged portion. Fitting the contact metal into the groove, pressing the rotating tool on the surface of the corresponding metal and running the entire surface of the metal contact, thereby metallically joining the entire surface of the metal and the structural part. To repair structures that do. 13. A method for repairing a reactor pressure vessel and / or a reactor internal structure made of iron, nickel, or an alloy of each of them, the equipment having a damaged portion that has become apparent on its surface. And repairing the damaged portion by inserting a rotating tool into the damaged portion and using frictional heat and plastic flow accompanying rotation of the rotating tool to repair the damaged portion. 14. A method for repairing a damaged portion having a surface portion which is a reactor pressure vessel and / or a reactor internal structure made of iron, nickel, or an alloy thereof. After removing the groove, a groove is formed, a metal plate is fitted into the groove, a rotary tool is inserted into the interface between the metal and the structure, and the periphery of the metal plate is metallically connected to the structure by friction stir welding. A method for repairing nuclear reactor equipment, characterized by joining. 15. A method for repairing a damaged portion of a surface of a reactor pressure vessel and a reactor internal structure made of iron, nickel or an alloy thereof, wherein the damaged portion is removed. After that, a groove is formed, a metal plate is fitted into the groove, a rotating tool is pressed in from the gold, and the entire surface of the metal plate and the structure are metallically joined by friction stir welding. The repair method of the reactor equipment. 16. A method for repairing a damaged surface according to any one of claims 10 to 15, wherein a rotating tool made of a material having a hardness at room temperature equivalent to Vickers hardness of 550 or more is used. A method for repairing a structure, wherein the damaged portion is repaired by a stir welding method. 17. The method according to claim 16, wherein the friction stir welding is performed while forcibly cooling the inside of the coolant, or the vicinity of the joint, with the coolant, either of air, an inert gas, or water. A method of repairing a structure characterized by being constructed.