JPH11142592A - Ultra-thick corrosion-resistant vessel and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inner-layer and-outer layer-integrated structure manufactured so that a strength material constituting the inner layer and a corrosion resistant material constituting the outer layer do not mix with each other at the time of welding by constituting the structure of a vessel main body obtained by integrally fitting a cylindrical outer layer vessel body and an inner layer vessel and an inner cover type inner layer cover and the like. SOLUTION: An ultra-pressure proof and corrosion resistant vessel 5 capable of being used for overpack and the like for radioactive waste disposal is constituted of a vessel body 6, an inner layer cover 7 and an outer layer cover 8. The vessel body 6 is formed to join an outer layer vessel body 11 made of titanium and the like and an inner layer vessel body 12 made of carbon steel and the like by shrinkage fitting and the like in a state where the upper end 11a of the outer layer vessel body 11 is slightly upward projected from the upper end of the inner layer vessel body 12. The opening part of the inner layer vessel body 12 and the inner layer cover 7 are made a shape in which an inner layer groove part 18 is formed at the time when they are fitted, and after housing of a vitrification body 10 and the like, padding welding is performed on the groove part 18. The outer layer cover 8 comprising a hanging part 20 and a cover plate 21 is integrated with the outer layer vessel body 11 by a corrosion resistant welding part 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be used as an overpack for disposing of radioactive waste in a geological disposal of used radioactive waste in a stable state in a nuclear reactor such as a nuclear power plant. And a method for manufacturing the same.

[0002]

2. Description of the Related Art Radioactive substances (radioactive waste, used fuel, etc.) generated in nuclear reactors such as nuclear power plants at high, medium and low radioactivity levels are classified into high, medium and low radioactivity levels. They are stored and stored in a dedicated sealed container suitable for each.

In order to store and store radioactive materials, first,
After the radioactive substance is vitrified to form a storage container called a vitrified body, and then the storage container is subjected to an overpacking process of further sealing with a sealed container called an overpack made of metal or the like, This sealed container is transported to a geological disposal site isolated from the living area, loaded into a disposal hole provided at the geological disposal site, and filled with a buffer material such as benite around the sealed container inside the disposal hole. Is performed.

[0004] In this case, since the overpack containing and sealing the vitrified body is stored and stored in a deep underground layer for a long period of time, it has a high strength that can withstand the earth pressure and a high corrosion resistance that can withstand corrosion at the same time. For this reason, a double-walled super-thick corrosion-resistant container having a thick inner layer having high strength and a thin outer layer having high corrosion resistance has been studied as an overpack.

By the way, in order to manufacture the above-described double-packed overpack, there is a condition that, since radioactive materials are handled, since all operations are performed on site by remote control, the manufacture must be simple and reliable. Also, when welding in the field, the inner layer material (such as carbon steel) that is a strength material and the outer layer material (such as titanium) that is a corrosion-resistant material are melted and mixed by welding heat, and the weld becomes brittle. There is a condition that welding between the material of the inner layer and the material of the outer layer must be performed while absolutely preventing the materials from being mixed.

As an overpack satisfying such conditions, for example, as shown in FIG. 5, an inner layer container 1 made of a strength material and an outer layer container 2 made of a corrosion resistant material are separately formed, and a vitrified body is formed of an inner layer container. An ultra-thick corrosion-resistant container 3 having an inner-layer / outer-layer separate structure in which the inner container 1 is housed and sealed in the outer container 2 after being housed and sealed in the inner container 1 has been considered.

[0007]

However, the ultra-thick corrosion-resistant container 3 in which the inner container 1 and the outer container 2 have a separate structure has the following problems.

That is, at the stage of on-site processing, after the vitrified body is housed and sealed in the inner container 1 and then the inner container 1 is housed and sealed in the outer container 2, the inner container 1 and the outer container 2 are tightly closed. Since it is difficult to fit, the inner container 1
The space 4 is formed between the outer layer container 2 and the outer layer container 2.

In this case, there is a possibility that the inner container 1 formed of the strength material may be corroded by oxygen in the air sealed in the space 4 or the like.

In view of the above situation, the present invention provides an inner-layer / outer-layer integrated structure container in which an inner layer made of a strength material and an outer layer made of a corrosion-resistant material are integrated, and the strength material and the outer layer constituting the inner layer are formed. It is an object of the present invention to provide a super-thick corrosion-resistant container and a method for manufacturing the same, which can reliably perform welding without melting and mixing both of the constituent corrosion-resistant material and the welding heat. Is what you do.

[0011]

According to the present invention, a bottomed cylindrical outer layer container main body and a bottomed cylindrical inner layer container main body are formed such that the upper edge of the outer layer container main body is larger than the upper end surface of the inner layer container main body. A container main body integrally fitted in a slightly protruded state, an inner lid that can be fitted and locked in a lid-like manner at an upper end opening of the inner container main body, and an inner surface of an opening of the inner container main body. An inner layer groove portion for forming a strength material welded portion provided between the inner layer lid and a peripheral surface of the inner layer lid, a hanging portion having the same diameter as the outer container body, and a lower end inside the hanging portion, An outer cover made of a cover plate fixed so as to protrude slightly below the lower end of the lowering portion, and a space between the lower surface of the hanging portion, the peripheral surface of the cover plate, and the upper edge of the outer container body. And an outer layer groove for forming a corrosion-resistant material welded portion provided in the container. Is shall.

In this case, the hanging portion of the outer layer lid is
A plurality of locking holes for locking the hanging device may be provided to the side.

Further, according to the present invention, at the stage of factory processing, the bottomed cylindrical outer container body and the bottomed cylindrical inner container body are separated by the upper end edge of the outer layer container body being the upper end surface of the inner layer container body. The container body is formed by fitting together so as to be slightly protruded to form a container main body. An inner layer groove portion is formed between the inner surface of the opening of the inner layer container body and the peripheral surface of the inner layer lid, and a hanging portion made of a corrosion-resistant material formed in a cylindrical shape having the same diameter as the outer layer container body, An outer layer lid is formed by a lid plate made of a corrosion-resistant material which is fixed to the inner lower end of the hanging portion and is dropped into the opening of the outer layer container body and fitted in a lid type, and the lower surface of the hanging portion and the lid plate are formed. An outer groove is formed between the peripheral surface and the upper edge of the outer container body. In a state in which the inner lid is fitted into the opening of the container body, a strength material is welded on the inner layer groove formed between the inner container body and the inner lid to form a strength material weld, Next, in a state where the cover plate of the outer layer lid is fitted into the opening of the outer layer container body, the outer layer groove formed between the outer layer container body, the hanging portion and the cover plate is welded. The present invention relates to a method for manufacturing a super-thick corrosion-resistant container, characterized in that a corrosion-resistant material weld is formed by welding.

Therefore, in the present invention, when the container main body is manufactured, the inner container main body and the outer container main body are fitted to each other by shrink fitting or cold fitting, so that the inner layer container main body made of a strength material and the corrosion resistant material are fitted. It is possible to reliably integrate the outer layer container body made of the above without any gap over the peripheral surface and the bottom surface.

Further, the strength material welding portion is formed in the upper end opening of the inner container body, and the corrosion resistant material welding portion is formed on the peripheral surface of the cover plate of the outer cover. When welding the respective welded parts, the strength material and the corrosion-resistant material do not melt and mix with each other when welding the respective welded parts, making welding easier and ensuring reliable welding This makes it possible to reliably prevent the occurrence of defects such as cracks or brittleness at each welded portion, and to improve the processing efficiency on site.

Further, since the corrosion-resistant material welding portion is formed on the peripheral portion of the outer layer lid, the upper surface of the lid plate is flattened.
In addition to facilitating the application and removal of the contact medium during the flaw detection inspection, the ultrasonic flaw detection head can inspect the strength material weld and the thickness of the inner cover over a wide range.

Furthermore, since the peripheral surface of the lid plate of the outer lid serves as the groove bottom, even when the lid plate of the outer lid is welded to the outer container main body, even in the case of a container body to which the back shield gas cannot be sufficiently applied. In the case of corrosion-resistant welding, the air is replaced with a welding shield gas in the welding shield chamber to prepare both the material and the shield (welding shield gas). Is argon or a mixed gas of argon and helium), and a good corrosion resistant material can be welded without oxidizing the weld back bead.

Further, the hanging portion of the outer layer lid is formed in a cylindrical shape having the same diameter as the outer layer container body, and a plurality of locking holes are provided in the hanging portion so that the hanging tool is locked to these. The shape can be smart without the projections and other parts protruding outside the hanging part of the outer lid, minimizing the storage space, and the hanging part can be made of a single plate In addition, the manufacture of the outer layer lid becomes easy.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention.

1 to 4, reference numeral 5 denotes an ultra-thick corrosion-resistant container according to the present invention, 6 denotes a container body of the ultra-thick corrosion-resistant container 5, 7 denotes a drop-down inner layer lid made of a thick-strength material, and 8 denotes a lid. A drop lid type outer lid 9 made of a corrosion-resistant material is a storage space for storing the vitrified body 10 formed in the container body 6. The ultra-thick corrosion-resistant container 5 is composed of the container body 6 and the inner lid 7. And an outer layer lid 8.

As shown in FIG. 1, the container main body 6 has an outer layer container main body 11 formed of a thin corrosion-resistant material formed in a bottomed cylindrical shape, and a thick-walled similarly formed bottomed cylindrical shape. The outer container body 11 is joined to the inner container body 12 without gaps by shrink fitting or cold fitting. In the figure, reference numeral 13 denotes the vitrified body 10 for the inner container body 12.
It is a spacer that is supported inside.

The upper edge 11a of the outer container body 11 is
The outer layer container 8 is formed so as to protrude upward by a small dimension from the upper end surface of the inner layer container body 12 in the circumferential direction, and when the outer layer lid 8 is fitted into the opening of the outer layer container body 11, the outer layer container The upper edge of the main body 11 is positioned slightly below the center of the thickness of the cover plate 21 of the outer layer cover 8.

The inner cover 7 is formed in a disk shape having substantially the same thickness as the thickness of the inner container body 12 in the radial direction.
The lower end of the inner cover 7 is formed with a flange-shaped protrusion 7a projecting radially outward over the entire circumference.
The backing metal 14 is provided so as to come into contact with the inner surface of the inner container body 12 when it is fitted into the opening of the inner container body 12.

As shown in FIG. 2, when the inner cover 7 is fitted into the opening, the projecting portion 7a of the inner cover 7 extends in the circumferential direction inside the opening of the inner container main body 12, as shown in FIG. There is provided a step portion 15 for locking over, and the step portion 15 makes the upper end surface of the inner container body 12 and the upper surface of the inner cover 7 flush with each other when the inner cover 7 is fitted into the opening. It is formed in the position which becomes.

Further, the step 1 on the inner surface of the inner container body 12
As shown in FIG. 2, a groove component 16 is provided in a portion higher than 5, and a groove component 17 is also provided on the outer peripheral surface of the inner cover 7. An inner layer groove portion 18 is formed between the inner layer container main body 12 and the inner layer lid 7 by the constituent portions 16 and 17, and a build-up welding is performed on the inner layer groove portion 18 to form a strength material welded portion 19, The inner container body 12 and the inner lid 7 are integrally fixed.

The outer lid 8 is composed of a hanging portion 20 and a disc-shaped lid plate 21 fixed to a lower portion of the hanging portion 20. The cover plate 21 is formed in a cylindrical shape having the same thickness and the same diameter, and the outer diameter of the cover plate 21 can be fitted into the hanging portion 20 and the outer container body 11.

Further, the cover plate 21 is fitted into the suspension portion 20 while slightly projecting downward from the lower end of the suspension portion 20, and a gap between the lower inner surface of the suspension portion 20 and the upper surface of the cover plate 21 is provided. By forming the fillet welded portion 22 by fillet welding, the hanging portion 20 and the cover plate 21 are integrally fixed.

Further, a groove 23 is formed on the lower end surface of the hanging portion 20. When the outer lid 8 is fitted into the opening of the outer container body 11, the groove 23 and the outer layer are formed. An outer layer groove portion 24 is formed by the upper end edge 11a of the container body 11, and a peripheral surface 21a of the cover plate 21 forms a groove bottom portion.

Then, the cover plate 21 is fitted into the opening of the outer layer container main body 11, and the corrosion resistant welding portion 25 is formed by overlay welding on the outer layer groove 24, thereby forming the outer layer container main body 1.
1, the cover plate 21 and the suspension unit 20 are integrally fixed.

In this case, since the strength material welding portion 19 and the corrosion-resistant material welding portion 25 are located at a certain distance from each other, the strength material and the corrosion-resistant material melt when welding the corrosion-resistant material welding portion 25. Mixing with each other is prevented, welding is facilitated and reliable welding can be performed. Defects such as cracks and brittleness at the welds 19 and 25 can be reliably prevented. Processing efficiency can be improved.

In the figure, reference numeral 26 denotes a suspender for the outer layer lid 8, 2
6a is a rod provided to be able to protrude and retract from the suspending device 26;
6b is a cylinder for extending and retracting the rod 26a, 26b
c is a locking hole formed on the upper surface of the hanging member 26, 26d is a hook of the transport device locked in the locking hole 26c of the hanging member 26, and 28 is formed in the hanging portion 20 of the outer layer lid 8. Locking hole, 29 is a suspending tool for the vitrified body 10, 30 is a suspending tool for the inner cover 7, 31 is a welding torch for welding the strength material weld 19, and 32 is a supersonic detector for detecting the strength material weld 19. An acoustic flaw detection head, 33 is a welding torch for welding the corrosion resistant material weld 25, and 34 is an ultrasonic flaw detection head for flaw detection of the corrosion resistant material weld 25.

Next, a procedure for manufacturing the super-thick corrosion-resistant container 5 having the above structure will be described.

First, at the stage of factory processing, as shown in FIG. 3A, the container body 6, the inner cover 7 and the outer cover 8 are separately manufactured.

That is, to manufacture the container main body 6, the outer layer container main body 11 is made of a corrosion-resistant material such as titanium into a predetermined thin and thick, bottomed cylindrical shape, and the inner layer container main body 12 is made of a strength material such as carbon steel. The inner container body 12 is formed with a stepped portion 15 for locking the inner cover 7 and a groove forming portion 16 in advance at the opening of the inner container body 12. Keep it.

When the inner lid 7 is fitted into the inner container main body 12 and locked on the step 15, the upper surface of the inner lid 7 and the opening end face of the inner container main body 12 are flush with each other. At a depth where

Next, the outer container body 11 is integrally fitted to the inner container body 12 by shrink-fitting or cold-fitting so that no gap is formed therebetween.

In order to manufacture the inner layer lid 7, the inner layer container body 1 is made of the same strength material as the inner layer container body 12 and has a thickness substantially the same as the radial thickness of the inner layer container body 12.
The inner cover 7 is formed to have an outer diameter that can be inserted into the opening, and a lower end of the inner cover 7 is formed with a flange-shaped protrusion 7a that protrudes radially outward over the entire circumference.

Further, on the peripheral surface of the inner layer cover 7, a groove forming portion 17 having a conical surface whose diameter gradually decreases upwards.
Is formed, and a backing metal 14 is fixed to the outer peripheral side of the lower surface of the inner layer lid 7 so as to be in contact with the inner peripheral surface of the inner layer container body 12 when the inner layer lid 7 is attached to the opening of the inner layer container main body 12. deep.

In order to manufacture the outer layer lid 8, first, the suspending portion 20 and the lid plate 21 are formed of a corrosion-resistant material having the same thickness as the outer layer container body 11 and a thin thickness.

The hanging portion 20 is formed by rolling and processing the plate material so as to have a cylindrical shape having the same outer diameter as the outer layer container body 11 and having a required length. It is formed in a disk shape having the same outer shape as the inner diameter of the main body 11,
The lid plate 21 is inserted into the lower end of the hanging portion 20 and the corners of the lid plate 21 and the hanging portion 20 are welded so that the lid plate 21 projects slightly downward from the lower end of the hanging portion 20. By forming the fillet weld 22 by means of the suspending portion 20 and the cover plate 21
Is fixed.

As described above, by manufacturing the suspension portion 20 with a single plate, the outer layer lid 8 can be easily manufactured.

On the lower end surface of the hanging portion 20, a groove forming portion 23 having a conical surface tapering downward is provided.

Further, as shown in FIG. 4 and described later, a suspending tool 26 for suspending the outer cover 8 by remote control and fitting the outer cover 8 to the outer container body 11 is attached to the suspending portion 20 of the outer cover 8. A plurality of locking holes 28 having a predetermined diameter for locking to the rod 26a are provided laterally.

In the present embodiment, a plurality of locking holes 28 are provided at equal intervals in the circumferential direction corresponding to the rods 26a of the suspenders 26 in the present embodiment.

Next, the case where the inner cover 7 and the outer cover 8 are welded to the container body 6 by remote control at the stage of on-site processing will be described.

First, as shown in FIG. 3 (b), the vitrified body 10 is gripped by a suspender 29 such as a manipulator, and the suspender 29 is moved to be housed in the container body 6; (C) As shown in FIG.
The upper edge of the inner lid 7 is gripped by
As shown in (d), the inner layer lid 7 is fitted into the opening of the container main body 6, and a strength material weld 19 is formed on the inner layer groove 18 by overlay welding with a welding torch 31 to form an inner layer container main body 12.
And the inner cover 7 are fixedly provided.

More specifically, when the inner lid 7 is fitted into the opening of the inner container body 12, the projection 7a of the inner lid 7 is locked to the step 15 and the inner groove 18 is formed. ,
The first layer valley welding to the inner layer groove 18 is performed by Tig welding using helium gas as a shielding gas, and after the first layer valley welding is completed, the remaining part of the inner layer groove 18 is shielded with argon gas. Tig welding using Mig or Mig
A welding wire made of a strength material is melted by welding, and a welding material is welded to a level flush with the upper end surface of the inner container body 12 and the upper surface of the inner cover 7 to form a strength material weld 19, and a polishing device or the like is used. Thereby, the upper surface of the strength material welding portion 19 is made flush with the upper end surface of the inner container body 12 and the upper surface of the inner cover 7.

Then, as shown in FIG. 3 (e), the upper surface of the strength material welding portion 19 whose upper surface is flush with the entire surface is scanned by the ultrasonic flaw detection head 32, thereby welding the strength material welding portion. An inspection is made to see if there is a flaw in 19.

As described above, since the opening end face of the inner layer container body 12, the upper surface of the strength material welding portion 19 and the upper surface of the inner layer lid 7 are flattened, the ultrasonic flaw detection head 32 used for flaw detection inspection is used.
The application and removal of the contact medium for use becomes easy, and the inspection of the plate thickness of the strength material welded portion 19 and the inner cover 7 by the above-described ultrasonic flaw detection head 32 becomes possible in a wide range.

In this embodiment, the inner lid 7 is held by the suspender 30 so that the upper peripheral edge of the inner lid 7 is gripped.
However, the present invention is not limited to this, and a gripping projection (not shown) is welded and fixed upward to the center of the upper surface of the inner cover 7 and the gripping projection is gripped by a hanging tool. After the inner cover 7 is suspended and the inner cover 7 is fitted to the inner container body 12, the gripping projection may be cut so as to be flush with the upper surface of the inner cover 7.

Next, as shown in FIG. 3 (f), the outer layer lid 8 is hung by the hanger 26 and fitted into the opening of the outer layer container body 11.

As shown in FIG.
It is formed in a disk shape with an outer diameter that can be inserted into the suspension portion 20 of the outer layer lid 8, and four cylinders 26b are built in the suspension portion 20 so that rods 26a can protrude and retract laterally at equal circumferential intervals. The hanging portions 20 are attached to the rods 26a projecting sideways.
Are locked to lock the respective locking holes 28. Reference numeral 26c denotes a locking hole provided on the upper part of the hanging member 26 for locking the hook 26d of the transfer device.

After the respective rods 26a and the locking holes 28 are roughly aligned, each rod 26a
When the hanging tool 26 is lowered into the outer layer cover 8 in a state where it is immersed, and then the rods 26a of the cylinders 26b are protruded, the rods 26a
The outer lid 8 is moved by lifting the suspender 26 in this state, and the outer lid body 8 is moved to the outer container body 1.
After lowering the outer lid 8 above the upper cover 1 and fitting it into the opening, each rod 26a is immersed and
a and the engagement hole 28 is released, and then the suspension 2
6 is lifted, whereby the fitting of the outer layer lid 8 is completed.

As described above, the outer lid body 8 is attached to the outer lid 8.
A plurality of locking holes 28 are provided in the hanging portion 20 and the hanging members 26 are locked in these, so that the hanging portion 20 of the outer layer lid 8 is provided. The projections and the like do not have a shape protruding outwardly from the outer surface 20.

When the outer lid 8 is fitted into the opening of the outer container body 11, the lower surface of the cover plate 21 of the outer lid 8 is closed by the opening end face of the inner container body 12, the strength material weld 19, and the upper surface of the inner cover 7. And the upper edge 11a of the outer container body 11
An outer layer groove 24 is formed between the outer layer lid 8 and the lower end surface of the hanging portion 20, and the peripheral surface 21 a of the cover plate 21 serves as a groove bottom.

After that, as shown in FIG. 3 (g), the outer layer groove portion 24 is welded over the entire circumference by a welding torch 33 to form a corrosion-resistant material welded portion 25.

In this case, the peripheral surface 21 of the lid plate 21 of the outer layer lid 8
a becomes the groove bottom, so that the outer layer lid 8
Even when the outer container body 11 to which the back shield gas cannot be applied when welding the lid plate 21 of the above, since the lid plate 21 which is a corrosion-resistant material plays the role of a backing metal, the welded back bead is not oxidized. Welding of corrosion-resistant materials becomes possible. still,
The process from the step of FIG. 3 (c) to the end of FIG. 3 (g) is defined as a welding shield chamber, in which air is replaced and the welding shield gas is filled.

Thereafter, the outer peripheral surface of the hanging portion 20 of the outer lid 8 and the outer peripheral surface of the outer container main body 11 are made flush with the surface of the corrosion-resistant material welding portion 25 by a polishing device or the like.

Then, as shown in FIG. 3 (h), the corrosion-resistant material welded by scanning the entire surface of the corrosion-resistant material welded portion 25 whose peripheral surface is flush with the ultrasonic flaw detection head 34. Inspect whether there is a flaw in the weld 25,
Finish the on-site machining operation.

As described above, in the present embodiment, the inner container body 12 and the outer container body 1 are manufactured when the container body 6 is manufactured.
1 is integrated by shrink-fitting or cold-fitting, so that they can be securely joined without any gap between them, and when the inner cover 7 and the outer cover 8 are welded at the stage of on-site processing. Since the strength material welding portion 19 and the corrosion-resistant material welding portion 25 are separated from each other by a certain distance, the strength material and the corrosion-resistant material do not melt and mix with each other.
The occurrence of defects such as cracks and brittleness at 9, 25 can be reliably prevented.

Further, since the upper portion of the inner cover 7 is easily flattened, it is easy to apply and remove the contact medium for the ultrasonic flaw detection head 32 used in the flaw detection inspection.
Inspection of the plate thickness of the strength material welded portion 19 and the inner layer cover 7 according to 2 can be performed in a wide range.

Further, when the cover plate 21 of the outer cover 8 is welded to the outer container body 11, the peripheral surface of the cover plate 21 of the outer cover 8 becomes a groove bottom. It plays the role of gold and enables good welding of corrosion-resistant materials without oxidation of the welding back bead.

Further, the hanging portion 20 of the outer layer lid 8 is formed in a cylindrical shape having the same diameter as the outer layer container body 11 and the locking hole 28 for hanging is provided. Since the projections and the like do not have a protruding shape, the space for storing the outer layer lid 8 can be minimized, and the hanging portion 20 can be manufactured by a single plate, so that the outer layer lid 8 can be easily manufactured.

[0065]

As described above, according to the present invention,
The following various excellent effects can be obtained.

1) At the stage of factory processing, the inner container body and the outer container body are integrated by shrink-fitting or cold-fitting, so that the inner container body made of a strength material and the outer container body made of a corrosion-resistant material are integrated. Can be securely joined without any gap over the peripheral surface and the bottom surface.

2) In addition, the strength material welding portion is formed in the opening at the upper end of the inner container body, and the corrosion-resistant material welding portion is formed on the peripheral surface of the cover plate of the outer layer lid. The strength material and the corrosion-resistant material are prevented from melting and mixing with each other when welding each welded part, so that the welded parts are separated from each other by a certain distance, making welding easier and ensuring reliable welding It is possible to reliably prevent the occurrence of defects such as cracks or brittleness at each welded portion, and to improve the processing efficiency on site.

3) Further, since the corrosion-resistant material welding portion is formed on the peripheral portion of the outer layer lid, the upper surface of the inner layer lid is flattened. Therefore, application and removal of a contact medium for an ultrasonic flaw detection head used at the time of flaw detection inspection. And the inspection of the thickness of the welded portion of the strength material and the thickness of the inner cover by the ultrasonic flaw detection head can be performed in a wide range.

4) Further, since the peripheral surface of the lid plate of the outer layer lid is the bottom of the groove, even when the lid plate of the outer layer lid is welded to the outer layer container main body, the container body to which the back shield gas cannot be applied, Since the lid plate, which is a corrosion-resistant material, plays the role of a backing metal, it is possible to weld a good corrosion-resistant material without oxidizing the welding back bead.

5) Further, since the hanging portion of the outer layer lid is formed in a cylindrical shape having the same diameter as the outer layer container main body and the locking hole for hanging is provided, a projection or the like projects outside the hanging portion. It becomes a smart shape without having to make a shape, and the space at the time of storage can be minimized, and the hanging portion can be made of a single plate, so that the outer layer lid can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an ultrathin corrosion-resistant container according to an example of an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a main part of FIG. 1 showing each welded portion.

3 (a) to 3 (e) are longitudinal sectional views showing a welding procedure between the inner container body and the inner cover, and FIGS. 3 (f) to 3 (h) are longitudinal sectional views showing a welding procedure between the outer vessel body and the outer cover. Yes, the process from step (c) to the end of (g) in the procedure is defined as a welding shield chamber, air is replaced, and the welding shield gas is filled.

FIG. 4 is a longitudinal sectional view showing a hanging tool for the outer cover.

FIG. 5 is a longitudinal sectional view showing an ultra-thick corrosion-resistant container studied conventionally.

[Explanation of symbols]

 Reference Signs List 5 super thick corrosion-resistant container 6 container main body 7 inner lid 8 outer lid 11 outer container main body 11a upper edge of outer container main body 12 inner layer main body 18 inner layer groove portion 19 strength material welding portion 20 hanging portion 21 lid plate 21a lid plate 23 Lower end surface of hanging portion 24 Outer layer groove 25 Corrosion-resistant material welded portion 28 Locking hole

Claims (3)

[Claims] 1. A bottomed cylindrical outer layer container main body and a bottomed cylindrical inner layer container main body are integrated with an upper edge of the outer layer container main body being slightly protruded from an upper end surface of the inner layer container main body. A container body that is fitted to the inner container body; an inner layer lid that can be fitted and locked in the form of a lid to the upper end opening of the inner layer container body; and an inner surface of the opening of the inner layer container body and a peripheral surface of the inner layer lid. An inner layer groove for forming a strength material welded portion provided therebetween, a hanging portion having the same diameter as the outer container body, and an inner lower end of the hanging portion, slightly lower than the lower end of the hanging portion. An outer layer lid comprising a lid plate fixedly protruding downward, and a corrosion-resistant material welded portion provided between a lower surface of the hanging portion, a peripheral surface of the lid plate, and an upper edge of the outer layer container body. An ultra-thick corrosion-resistant container, comprising: 2. The ultra-thick corrosion-resistant container according to claim 1, wherein a plurality of locking holes for locking the hanging members are provided in the hanging portion of the outer layer lid toward the side. 3. At the stage of factory processing, the bottomed cylindrical outer layer container main body and the bottomed cylindrical inner layer container main body are separated from each other so that the upper edge of the outer layer container main body is slightly smaller than the upper end surface of the inner layer container main body. The inner container body is formed by fitting together so as to be in a protruding state, and an inner cover made of a thick-strength material that is dropped into the opening of the inner container body to be fitted in a lid type is formed. A hanging portion formed of a corrosion-resistant material having a cylindrical shape having the same diameter as the outer container body, forming an inner layer groove portion between the inner surface of the opening and the peripheral surface of the inner layer lid; A lid plate formed of a corrosion-resistant material which is fixed to an inner lower end of the outer layer container and is dropped into the opening of the outer layer container body and fitted in a lid type, and the lower surface of the hanging portion, the peripheral surface of the lid plate, and the outer layer An outer layer groove is formed between the upper edge of the container body and the inner layer container body at the stage of on-site processing. In a state in which the inner lid is fitted in the mouth, a strength material is welded on the inner layer groove formed between the inner container body and the inner lid to form a strength material weld, and In a state in which the cover plate of the outer layer lid is fitted into the opening of the outer layer container main body, the outer layer groove formed between the outer layer container main body, the hanging portion, and the lid plate is welded and welded to form a corrosion resistant material. A method for producing a super-thick corrosion-resistant container, comprising forming a weld.