JP7264784B2 - Method for manufacturing nuclear equipment components and nuclear equipment components - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a member for nuclear power equipment and a member for nuclear power equipment.

A hot isostatic pressing method (HIP method) is known as a processing technique for metal members. As a technique related to the HIP method, the technique described in Patent Document 1 is known. In Patent Document 1, a processing material is filled in a capsule having an opening at one end, vacuum degassed through the opening, and then the opening is sealed to manufacture a processing body. It is placed under the hot isostatic pressure pressurizing device, and heated in a state in which the sealing portion is surrounded and supported by a support having a heat insulating material provided in the lower low temperature portion of the hot isostatic pressure pressurizing device. A hot isostatic pressing method is described, which is characterized by performing a hot isostatic pressing treatment. (See especially claim 1).

JP-A-2-294407

By the way, by using the HIP method, different metal members can be joined together (for example, diffusion joining). Such bonding is hereinafter referred to as "HIP bonding". However, in the technique described in Patent Literature 1, a metal member that can be HIP-bonded is limited to a size that can be accommodated in a high-pressure container that performs hot isostatic pressing. Therefore, there is a demand for a new technique that enables HIP bonding even for large metal members that cannot be accommodated in conventional high-pressure vessels.

The problem to be solved by the present invention is to provide a method for manufacturing a nuclear power equipment member and a nuclear power equipment member capable of HIP joining even a large metal member.

The present invention is a method for manufacturing a nuclear power facility member comprising a first metal member and a second metal member joined to the first metal member via a sintered metal, wherein the first metal member of the first metal member an arranging step of arranging a flexible defining member defining a defined space facing both the first joint surface and the second joint surface of the second metal member; a filling step of filling a metal raw material; and injecting a gas into a gas space formed on a side of the defining member opposite to the defining space, and propagating gas pressure to the metal raw material through the defining member. a HIP step of forming the metal sintered body in the defined space by performing hot isostatic pressing of the metal raw material in the defined space by Heating is performed by heat of a heating mechanism arranged outside the defined space, and the heating mechanism arranged so as to cover the defined space, and the first metal member other than the arrangement portion of the heating mechanism and a cooling mechanism disposed on the outer surface of at least one of the second metal members. Other solutions will be described later in the detailed description.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the nuclear power equipment member and the nuclear power equipment member which can HIP-join even a large-sized metal member can be provided.

It is a flow chart which shows the manufacturing method of this embodiment. It is a figure which shows the nuclear power equipment member manufactured by the manufacturing method of this embodiment. FIG. 10B is a view for explaining an arrangement step, and shows a state in which the second metal member is fitted in the reaction portion formed integrally with the first metal member. 4 is a cross-sectional view taken along the line BB of FIG. 3; FIG. FIG. 11 is a diagram for explaining the first pressure adjustment step, and is a diagram showing a state in which the defining member protrudes toward the gas space. It is a figure explaining a 2nd pressure adjustment process, and is a figure which shows a mode that the defined space filled with the metal raw material is pressure-reduced. It is a figure explaining a HIP process, and is a figure which shows a mode that gas is inject|poured into gas space. It is a figure explaining a HIP process, and is a figure which shows a mode that a metal raw material is heated. FIG. 10 is a diagram for explaining the cooling process, and shows a state in which the heating mechanism and heat insulating material used in the HIP process are removed from the first metal member and the second metal member. It is a figure explaining an excision process, and is an A section enlarged view of FIG. It is a figure which expands and shows the metal sintered compact of FIG. 10A. FIG. 10 is a view according to another embodiment, showing a reaction section with a metal forging member arranged in a defined space; FIG. 5 is a diagram according to another embodiment, showing a temperature control mechanism with a cooling mechanism;

Hereinafter, a form (this embodiment) for carrying out the present invention will be described. However, the present invention is by no means limited to the following content and the content of the drawings, and can be arbitrarily modified within the scope that does not significantly impair the effects of the present invention. The present invention can be practiced by combining different embodiments. In the following description, the same reference numerals are given to the same members in different embodiments, and overlapping descriptions are omitted.

FIG. 1 is a flow chart showing the manufacturing method of this embodiment. Moreover, FIG. 2 is a figure which shows the nuclear power equipment member manufactured by the manufacturing method of this embodiment. The manufacturing method shown in FIG. 1 is a method for manufacturing the nuclear facility member 10 shown in FIG.

A nuclear power facility member 10 includes a first metal member 1 and a second metal member 2 joined to the first metal member 1 via a metal sintered body 3 . In the example shown in FIG. 2 , a tubular first metal member 1 and a tubular second metal member 2 are joined by a metal sintered body 3 . The metal sintered body 3 is produced by the HIP method, the details of which will be described later.

The nuclear facility member 10 is, for example, a pressure vessel (not shown). The pressure vessel includes, for example, a pressure vessel main body (not shown), a nozzle, and an isolation valve. The first metal member 1 is, for example, a nozzle joined to the pressure vessel main body, and the second metal member 2 is joined to the nozzle. It is an isolation valve that Both the nozzle and the isolation valve have circular tube ends, and the circular tubes at the ends are HIP-joined to each other. In addition to pressure vessels, nuclear facility members 10 include, for example, nuclear reactors, containment vessels, pressure control chambers, turbines, generators, condensers, long pipes connecting these, valves connected to these long pipes, and the like. , it is applicable to nuclear power facilities that are relatively large and difficult to accommodate in a high-pressure vessel in the conventional HIP method.
2 will be described later with reference to FIG. 3, FIG. 10A, and the like.

In the arranging step S1, as shown in FIG. 3, which will be described later, a defining space 30 facing both the joint surfaces of the first joint surface 1a of the first metal member 1 and the second joint surface 2a of the second metal member 2 is formed. This is the step of disposing the defining flexible defining member 40 . The placement step S1 will be described with reference to FIG.

FIG. 3 is a diagram for explaining the placement step S1, and shows a state in which the second metal member 2 is fitted in the reaction portion 60 integrally formed with the first metal member 1. As shown in FIG. FIG. 3 is an enlarged view of the joint portion between the first metal member 1 and the second metal member 2, which are made of circular pipes, for example, as described above. Specifically, the portion A shown in FIG. 2 is formed by subjecting the portion shown in FIG. That is, the first metal member 1 and the second metal member 2 are HIP-joined at the portion shown in FIG. be done.

The first metal member 1 has a reaction portion 60 which is continuously formed at the end of the first metal member 1 . The reaction portion 60 is formed to protrude from the end portion of the first metal member 1 . The reaction portion 60 has a fitting portion 61 on the side opposite to the side where the first metal member 1 extends. Although not shown in FIG. 3 , the fitting portion 61 is formed along the entire circumference of the tubular first metal member 1 in this embodiment. Further, the end of the second metal member 2 is provided with an overhanging portion 2b that overhangs like a flange. The protruding portion 2b is also formed over the entire circumference of the cylindrical second metal member 2, although not shown in FIG. The radial length of the protruding portion 2b (length in the vertical direction of the paper surface in FIG. 3) substantially matches the radial length of the fitting portion 61 (the vertical length in the paper surface of FIG. 3). can be fitted into the fitting portion 61 .

A temporary welded portion 70 is formed at the fitting portion between the fitting portion 61 and the projecting portion 2b so as to fill the gap between them. The decompression state of the defined space 30 can be maintained by the temporary welded portion 70, although the details will be described later.

The reaction section 60 internally includes a defined space 30 and a gas space 31 . The defined space 30 is a space facing both the first joint surface 1 a of the first metal member 1 and the second joint surface 2 a of the second metal member 2 . The defined space 30 is formed in an annular shape along the first joint surface 1a and the second joint surface 2a. The reaction section 60 has an opening 53 and a communication passage 54 . The defined space 30 communicates with the outside through a communication path 54, and can be filled with, for example, a powdered metal raw material 80 (not shown in FIG. 3) through an opening 53 exposed to the outside (described later).

The gas spaces 31 are formed radially inside and outside the defined space 30 . The reaction section 60 has an opening 51 and a communication passage 52 . The gas space 31 communicates with the outside through a communication passage 52, and a high-pressure inert gas (described later) can be injected into the gas space 31 through the opening 51 exposed to the outside (described later).

The reaction section 60 includes a defining member 40 arranged to separate the defining space 30 and the gas space 31 . The defining member 40 is fixed to the inner wall 60a of the reaction section 60 over the entire circumferential direction by, for example, brazing, welding, or the like. The defining member 40 is arranged on each of the radial inner wall 60a and the radially outer inner wall 60a of the defining space 30, and both are arranged so as to make the defining space 30 and the gas space 31 airtight. Therefore, the defining space 30 is defined mainly by the defining members 40, 40, the first joint surface 1a, and the second joint surface 2a. The location of the defining member 40 will be described with reference to FIG.

4 is a cross-sectional view taken along the line BB of FIG. 3. FIG. The defining members 40 , 40 extend in the circumferential direction of the annular first metal member 1 as shown. A defined space 30 is formed between the defining members 40 , 40 . The defined space 30 can be filled with a metal raw material 80 (not shown in FIG. 4) through the communication passage 54 . A gas space 31 is formed between the defining member 40 and the communicating passage 52 . The gas spaces 31 are formed radially outward and inward, respectively.

Returning to FIG. 3, the defining member 40 is made of a flexible metal material, such as metal foil. By configuring the defining member 40 with a metal foil, the metal foil can be deformed according to the pressure difference between the defining space 30 and the gas space 31, and the gas pressure in the gas space 31 can be applied to the defining space 30 via the metal foil. It can propagate to the metal raw material 80 inside. The metal material of the defining member 40 is, for example, SUS, and the thickness of the defining member 40 is, for example, 5 μm or more and 100 μm or less.

In addition, in the example of FIG. 3 , the reaction section 60 is formed integrally with the first metal member 1 , but may be formed integrally with the second metal member 2 .

Returning to FIG. 1, the first pressure adjustment step S2 is a step of making the pressure in the defined space 30 higher than the pressure in the gas space 31 after the placement step S1 and before the filling step S3. By including the first pressure adjustment step S<b>2 , the defining member 40 can be bent like a diaphragm, and the defining member 40 can be projected toward the gas space 31 . The first pressure adjustment step S2 will be described with reference to FIG.

FIG. 5 is a diagram for explaining the first pressure adjustment step S2, and shows a state in which the defining member 40 protrudes toward the gas space 31 side. The first pressure adjustment step S2 can be performed by reducing the pressure in the gas space 31, for example. The gas space 31 can be depressurized, for example, by connecting a hose 90 to the opening 51 and degassing via the hose 90 and the communication passage 52 as indicated by the solid line arrow. However, the defining space 30 may be pressurized by injecting air into the gas space 31 through the opening 53 and the communicating passage 54 .

For degassing, for example, a vacuum pump (not shown) can be used. Although the degree of pressure reduction is not particularly limited, the pressure in the gas space 31 can be set to about 750 hPa, for example. The decompression speed can be, for example, 50 Pa/min or less, preferably 10 Pa/min or less. By setting the pressure and depressurization speed to this level, it is possible to suppress large deformation of the defining member 40 and to suppress breakage of the defining member 40 .

Returning to FIG. 1, the filling step S3 is a step of filling the defined space 30 with the metal raw material 80 . Filling of the metal raw material 80 into the defined space 30 can be performed through the opening 53 and the communication path 54 as described above. It is preferable to fill the defined space 30 as densely as possible so as not to generate gaps. As a result, the content of pores 3b (described later) in the metal sintered body 3 generated after firing can be reduced.

Here, it is preferable to maintain the state in which the defining member 40 is bent (for example, the depressurized state of the gas space 31) after depressurization in the first pressure adjustment step S2. Therefore, the filling step S<b>3 is preferably performed in a state where the pressure in the defined space 30 is higher than the pressure in the gas space 31 . As a result, the metal source material 80 can be filled into the demarcated space 30 whose internal volume is increased by projecting the delimiting member 40 toward the gas space 31 side, and the amount of the metal source material 80 filled into the demarcated space 30 can be increased. can. After filling, it is preferable to release the decompressed state of the gas space 31 and return the pressure to, for example, the atmospheric pressure.

The physical properties and components of the metal raw material 80 to be filled are not particularly limited. However, it is preferable to use the metal raw material 80 having physical properties and components that facilitate hot isostatic pressing in the HIP step S5 described later. Specifically, for example, a metal raw material 80 composed of a titanium-nickel-based alloy powder having an average particle size of 100 μm or less, preferably 50 μm or less as measured by a laser diffraction particle size distribution measuring device can be used. However, it is not limited to this.

It is preferable to perform the filling while vibrating the whole of the first metal member 1 and the second metal member 2, for example. As a result, the metal raw material 80 can be densely filled in the defined space 30 in the entire circumferential direction. Moreover, it is preferable to dry the metal raw material 80 to be filled in advance. By drying, the metal raw material 80 can be easily and densely filled in the entire circumferential direction of the defined space 30 .

The second pressure adjustment step S4 is a step of depressurizing the defined space 30 after the filling step S3 and before the HIP step S5. The second pressure adjustment step S4 will be described with reference to FIG.

FIG. 6 is a diagram for explaining the second pressure adjustment step S4, and shows how the defined space 30 filled with the metal raw material 80 is decompressed. Depressurization of the defined space 30 can be performed, for example, by connecting a hose 91 to the opening 53 and degassing via the hose 91 and the communication passage 54 as indicated by the solid line arrow. For decompression, for example, a vacuum pump can be used. The degree of pressure reduction is preferably vacuum or close to vacuum, and the pressure in the defined space 30 is, for example, 10 Pa or less, preferably 1 Pa or less, and more preferably 0.1 Pa or less. The decompression speed can be, for example, 50 Pa/min or less, preferably 10 Pa/min or less.

By the second pressure adjustment step S4, the defined space 30 can be decompressed before the HIP step, and the content of pores 3b (described later) in the metal sintered body 3 generated after the HIP step can be reduced. In addition, due to the reduced pressure after the filling step S3, the defining member 40 protruding toward the gas space 31 side along the filled metal raw material 80 comes into close contact with the metal raw material 80 so as to protrude toward the defining space 30 side. , the deformation of the defining member 40 is limited. As a result, large deformation of the defining member 40 can be suppressed, and breakage of the defining member 40 can be suppressed.

After the defined space 30 is decompressed, a temporary weld 71 (see FIG. 7) is formed in the opening 53 to seal the defined space 30 .

Returning to FIG. 1, in the HIP step S5, gas is injected into the gas space 31 formed on the opposite side of the defining member 40 from the defining space 30, and the gas is introduced into the metal raw material 80 via the defining member 40. This is a step of forming the metal sintered body 3 in the defined space 30 by performing hot isostatic pressurization of the metal raw material 80 in the defined space 30 by pressure propagation. The HIP step S5 will be described with reference to FIGS. 7 and 8. FIG.

FIG. 7 is a diagram for explaining the HIP step S5, showing how gas is injected into the gas space 31. As shown in FIG. Gas can be injected into the gas space 31 by connecting a hose 90 to the opening 51 and injecting through the hose 90 and the communication passage 52 as indicated by the solid line arrow. Injection can be performed, for example, using a high pressure pump (not shown). The injected gas is preferably an inert gas such as argon gas or nitrogen gas.

Here, the metal raw material 80 is densely filled in the defining space 30 along the defining member 40 protruding toward the gas space 31 side. Therefore, even if the gas is injected into the gas space 31, the deformation of the defining member 40 is restricted, so that the defining member 40 remains projecting toward the gas space 31 as shown.

It is preferable to inject the gas so that the pressure in the gas space 31 reaches a predetermined pressure for hot isostatic pressurization of the metal raw material 80 . The predetermined pressure referred to here differs depending on the constituent metals of the first metal member 1 and the second metal member and the constituent metals of the metal raw material 80, but is generally a pressure value within the range of 75 MPa or more and 250 MPa or less. That is, the HIP step S5 is preferably performed at a pressure of 75 MPa or more and 250 MPa or less as the pressure in the gas space 31 . By setting the pressure of the gas space 31 within this range, the gas pressure is propagated through the defining member 40, and hot isostatic pressurization of the metal raw material 80 can be performed at a pressure of 75 MPa or more and 250 MPa or less. In addition, the pressure of the gas space 31 is preferably 100 MPa or more and 200 MPa or less.

In the reaction section 60 , no pressure is applied to the metal raw material 80 from the axial direction (horizontal direction of the drawing) of the cylindrical first metal member 1 and the second metal member 2 . That is, pressure is applied to the metal raw material 80 from the radial direction (vertical direction on the paper surface) through the defining member 40, but no pressure is applied from the axial direction (horizontal direction on the paper surface). This is because the first joint surface 1a of the first metal member 1 and the second joint surface 2a of the second metal member 2 are fixed ends when viewed from the metal raw material 80 . Therefore, the movement of the metal raw material 80 to which the gas pressure is propagated through the partition member 40 is restricted by the first joint surface 1a and the second joint surface 2a. Therefore, the metal raw material 80 is pushed back by the first joint surface 1a and the second joint surface 2a by the gas pressure via the partitioning member 40 (law of action and reaction). As a result, the metal raw material 80 is pressurized from all directions with approximately the same pressure, and HIP bonding is realized.

In the illustrated example, the defining members 40 are arranged so as to be symmetrical in the radial direction when viewed from the metal raw material 80 (symmetrical in the vertical direction of the paper surface). Only one defining member 40 may be arranged, that is, only one portion may be used for propagating the gas pressure to the metal raw material 80, but the viewpoint is to pressurize the metal raw material 80 from all directions with the same pressure. Therefore, it is preferable to arrange a plurality of defining members 40 as shown in the drawing, and it is particularly preferable to arrange the defining members 40 so as to be symmetrical with respect to the metal raw material 80 as shown in the drawing.

It is preferable to inject the gas so that the pressure increase rate in the gas space 31 is 10 Pa/min or more and 50 Pa/min or less. By increasing the pressure in the gas space 31 at the above-described pressure increase rate to a predetermined pressure at which hot isostatic pressurization of the metal raw material 80 is performed, the pressure fluctuates due to the pressure difference between the defining space 30 and the gas space 31 . Deformation of the defining member 40 can be moderated. As a result, damage to the defining member 40 can be suppressed.

The temperature of the gas supplied to the gas space is preferably 5°C or higher and 40°C or lower. By using a gas of 5° C. or more and 40° C. or less, which is normal temperature or a temperature close to normal temperature, a general-purpose high-pressure pump that can be used at normal temperature can be used.

The HIP step S5 is preferably performed by heating with the heat of the heating mechanism 100 arranged outside the defined space 30 . By heating with the heat of the heating mechanism 100 arranged outside, the metal raw material 80 can be heated by a simple method. The heating mechanism 100 will be described with reference to FIG.

FIG. 8 is a diagram for explaining the HIP step S5, showing how the metal raw material 80 is heated. In FIG. 8 , the hose 90 is arranged inside the heating mechanism 100 for convenience of illustration, but the hose 90 may be arranged outside the heating mechanism 100 .

Heating of the reaction section 60 in the HIP step S<b>5 is performed by a temperature control mechanism 65 having a heating mechanism 100 . The heating mechanism 100 is arranged on the outer surface of the reaction section 60 so as to cover the defined space 30 . Specifically, the heating mechanism 100 is, for example, a high-frequency induction heating coil. 1 is wound around a metal member 1; A power supply (not shown) is connected to the high-frequency induction heating coil, and the heating mechanism 100 can heat the metal raw material 80 in the defined space 30 by energizing the power supply.

A heat insulating material 101 (heat insulating material) is installed between the heating mechanism 100 and the first metal member 1 . The heat insulating material 101 is installed so as to cover at least the defined space 30 on the surfaces of the first metal member 1 and the second metal member 2 . By installing the heat insulating material 101, the heating efficiency of the heating mechanism 100 can be enhanced.

Although the heating temperature varies depending on the constituent metals of the first metal member 1 and the second metal member 2 and the constituent metals of the metal raw material 80, it is preferably approximately 800° C. or higher and 1200° C. or lower. That is, the HIP step S5 is preferably performed by heating at a predetermined heating temperature of 800° C. or higher and 1200° C. or lower. By setting the temperature within this range, the metal raw material 80 can be sintered in the defined space 30 . The heating time can be, for example, 1 hour or more and 10 hours or less as the time to reach the temperature within the above temperature range.

For heating to a predetermined heating temperature, the rate of temperature increase in the defined space 30 is, for example, 2° C./min or more, preferably 5° C./min or more, and the upper limit is, for example, 10° C./min or less, preferably 7° C./min or less. It is preferably carried out by raising the temperature at . By setting the temperature rise rate within the above range, the pressure fluctuation in the defined space 30 accompanying the temperature rise can be reduced.

Heating can be performed in a state in which a hose 90 connected to a high-pressure pump (not shown) is connected to the opening 51 and the gas pressure in the gas space 31 is maintained at a predetermined pressure (75 MPa or more and 250 MPa or less in the above example). preferable. That is, the HIP step S5 is preferably performed while the gas pressure in the gas space 31 is maintained at a predetermined pressure. As a result, even if the pressure in the defining space 30 is likely to fluctuate due to thermal expansion and contraction of the metal raw material 80 and surrounding members due to heating, the defining member 40 is bent in accordance with the pressure fluctuation in the defining space 30, and the image is drawn. The pressure in the gas space 30 can be maintained at the pressure in the gas space 31 .

By pressurizing and heating the metal raw material 80, the metal raw material 80 is put into a hot isostatic press state in the defined space 30, and the first joint surface 1a and the second joint surface 2a are HIP-joined by the metal sintered body 3. be.

Returning to FIG. 1, the cooling step S6 is a step of cooling the first metal member 1 and the second metal member 2 by, for example, natural cooling after being heated by the heating mechanism 100. FIG. Cooling can be performed by removing the heating mechanism 100 and the heat insulating material 101 from the first metal member 1 and the second metal member 2 and leaving them at room temperature, for example.

FIG. 9 is a diagram for explaining the cooling step S6, and shows a state in which the heating mechanism 100 and the heat insulating material 101 used in the HIP step S5 are removed from the first metal member 1 and the second metal member 2. FIG. As shown in the drawing, the metal raw material in the defined space 30 (see FIG. 8, etc.) is sintered by heating and pressurization, and the metal sintered body 3 is generated in the defined space 30 . The metal sintered body 3 joins the first joint surface 1 a of the first metal member 1 and the second joint surface of the second metal member 2 .

In the illustrated example, the extension of the first metal member 1 other than the portion forming the reaction portion 60 (that is, the extension of the portion other than the portion projecting outward) and the extension of the second metal member 2 other than the portion forming the projecting portion 2b ( That is, the extensions other than the portions that protrude outward) are all located on the same straight line C indicated by the two-dot chain line. Outside the straight line C located radially outward of the circular tubular first metal member 1 and the circular tubular second metal member 2, and inside the straight line C located radially inward, the communicating path 54 and the temporary welded portion are provided, respectively. 70, 71, defining member 40, etc. are present. Therefore, in the cutting step S7, which will be described later, by cutting along the straight lines C, C, an unnecessary portion that is a portion further outside the straight line C on the outer side in the circumferential direction and an unnecessary portion further inside the straight line C on the inner side in the circumferential direction is removed. be done.

After the cooling step S6 and before the later-described cutting step S7, another heat treatment step may be performed as necessary. In this case, the hose 90 may be removed from the opening 51 if pressurization is unnecessary.

Returning to FIG. 1, the cutting step S7 is a step of forming the nuclear facility member 10 by cutting unnecessary portions. Specifically, as described with reference to FIG. 9, the outer and inner portions in the circumferential direction are cut off along straight lines C and C in FIG.

FIG. 10A is a diagram for explaining the cutting step S7, and is an enlarged view of part A in FIG. When the outer side and the inner side in the circumferential direction are cut off along straight lines C and C in FIG. 9, the nuclear power facility member 10 shown in FIG. 10A is formed. The portion shown in FIG. 10A corresponds to the enlarged view of the portion A in FIG. 2 described above.

FIG. 10B is an enlarged view of the metal sintered body 3 of FIG. 10A. The metal sintered body 3 is composed of a set of metal crystal grains 3a. The metal sintered body 3 is a metal sintered body produced by the HIP method. Therefore, the size of the pores 3b included in the metal sintered body 3 is smaller than the pores in the metal structure obtained by casting, forging, welding, or the like. Specifically, in the nuclear power equipment member 10, the size of the pores 3b contained in the metal sintered body 3 is 50 nm or more and 200 nm or less in the observation cross section of the metal sintered body 3 with an electron microscope (for example, the cross section shown in FIG. 10B). , preferably 100 nm or less. Therefore, the metal sintered body 3 is dense, and the bonding strength between the first metal member 1 and the second metal member 2 can be increased. As a result, the reliability of the nuclear equipment member 10 can be improved.

The size of the pores 3b contained in the metal sintered body 3 can be determined by observing an arbitrary cross section of the metal sintered body 3 with a scanning electron microscope or the like, and measuring the size of the pores 3b in the observed cross section (the longest part size) can be determined.

In the above observed cross section, it is preferable that 70% or more of the pores 3b contained in the metal sintered body 3 have a size of 50 nm or more and 100 nm or less. As a result, the number of particularly small pores 3b among all the pores 3b can be increased to 70% or more, and the bonding strength between the first metal member 1 and the second metal member 2 can be further increased. As a result, the reliability of the nuclear equipment member 10 can be further improved.

70% or more of the pores 3b in the observation cross section means that the size of 70% or more of all the pores 3b observed in any one observation cross section is within the above range.

The porosity of the metal sintered body 3 is preferably 0.5% or less, more preferably 0.3% or less, and particularly preferably 0.1% or less. When the porosity is within this range, the content of pores 3b can be reduced, and the strength of the metal sintered body 3 can be improved. Thereby, the intensity|strength of the nuclear power equipment member 10 can be improved.

The porosity can be determined by dividing the sum of the volume of pores communicating with the outside (open pores) and the volume of pores enclosed inside (closed pores) by the total volume.

According to the manufacturing method of the present embodiment, particularly the manufacturing method including the arranging step S1, the filling step S3, and the HIP step S5, the metal sintered body 3 is generated in the defining space 30 formed by arranging the defining member 40. Then, the first joint surface 1a and the second joint surface 2a can be joined by the produced metal sintered body 3 (HIP sintered body). Thereby, the first metal member 1 and the second metal member 2 can be HIP-joined without housing the first metal member 1 and the second metal member 2 in a high-pressure container. Therefore, even if the first metal member 1 and the second metal member 2 are too large to be accommodated in a conventional high-pressure vessel, they can be HIP-joined.

In particular, the size of the pores 3b of the metal sintered body 3 produced by the HIP method is small, and the metal sintered body 3 is dense. Therefore, the bonding strength between the first metal member 1 and the second metal member 2 is high, and the nuclear equipment member 10 having excellent reliability can be manufactured.

FIG. 11 is a diagram according to another embodiment, showing a reaction section 60A in which a metal forging member 120 is arranged in the defined space 30. As shown in FIG. 60 A of reaction parts are equipped with the metal forging member 120 formed by forging. The forged metal member 120 has, for example, a rectangular cross-section, and is configured in an annular shape that can be accommodated in the defined space 30 over the entire circumferential direction of the defined space 30 . The filling step S3 described above with reference to FIG. 1 is performed by accommodating the metal raw material 80 in the defined space 30 in which the metal forging member 120 is accommodated.

By filling the defined space 30 in which the metal forging member 120 is previously accommodated with the metal raw material 80, the fillable volume of the defined space 30 is reduced, so that the filling time can be shortened. In addition to this, the strength of the metal sintered body 3 can be increased by the metal forged member 120 serving as the core.

FIG. 12 is a diagram according to another embodiment, showing a temperature control mechanism 65A including a cooling mechanism 130. FIG. The temperature control mechanism 65A includes the heating mechanism 100 and the cooling mechanism 130 described above. The HIP step S5 is performed using the temperature control mechanism 65A.

In the illustrated example, the cooling mechanism 130 is a metal radiation fin. The cooling mechanism 130 is arranged on the outer surfaces of the first metal member 1 and the second metal member 2 (either one of them may be used), except where the heating mechanism 100 is arranged. Specifically, the cooling mechanism 130 extends in the axial direction of the tubular first metal member 1 and the second metal member 2 in each of the first metal member 1 and the second metal member 2 . Therefore, in the illustrated example, heat dissipation in the axial direction is facilitated.

As described above, the heating mechanism 100 is arranged to cover the defined space 30 . This promotes heating of the metal raw material 80 inside the defined space 30 by the heating mechanism 100 . However, the portions other than the defined space 30 do not need to be heated. Therefore, a cooling mechanism 130 is installed in a portion away from the defined space 30, that is, in a portion other than the portion where the heating mechanism 100 is arranged, in order to promote heat dissipation. As a result, it is possible to suppress the thermal influence in portions other than the defined space 30 .

1 First Metal Member 10 Nuclear Equipment Member 100 Heating Mechanism 101 Heat Insulating Material 120 Metal Forged Member 130 Cooling Mechanism 1a First Joining Surface 2 Second Metal Member 2a Second Joining Surface 2b Overhang 3 Metal Sintered Body 30 Defined Space 31 Gas space 3a Crystal grain 3b Pore 40 Demarcation member 51 Opening 52 Communication path 53 Opening 54 Communication path 60, 60A Reaction part 60a Inner wall 61 Fitting part 65, 65A Temperature control mechanism 70 Temporary welding part 71 Temporary welding part 90 Hose 91 Hose C Straight line S1 Placement step S2 First pressure adjustment step S3 Filling step S4 Second pressure adjustment step S5 HIP step S6 Cooling step S7 Cutting step

Claims (13)

A method for manufacturing a nuclear facility member comprising a first metal member and a second metal member joined to the first metal member via a metal sintered body,
an arrangement step of arranging a flexible defining member defining a defining space facing both the first joint surface of the first metal member and the second joint surface of the second metal member; and,
a filling step of filling the defined space with a metal raw material;
A gas is injected into a gas space formed on the opposite side of the defining member from the defining space, and the metal is placed in the defining space by propagation of gas pressure to the metal source via the defining member. a HIP step of forming the metal sintered body in the defined space by performing hot isostatic pressing of raw materials ;
The HIP step is
Heating is performed by the heat of a heating mechanism arranged outside the defined space, and
The heating mechanism arranged so as to cover the defined space, and the cooling mechanism arranged on the outer surface of at least one of the first metal member and the second metal member other than the portion where the heating mechanism is arranged. performed using a temperature control mechanism comprising
A manufacturing method for nuclear power equipment components. 2. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the HIP step is performed in a state where the gas pressure in the gas space is maintained at a predetermined pressure. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the HIP step is performed at a pressure of 75 MPa or more and 250 MPa or less in the gas space. 4. The method of manufacturing a member for nuclear power equipment according to claim 3, wherein the injection of the gas is performed so that the pressure increase rate in the gas space is 10 Pa/min or more and 50 Pa/min or less. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the temperature of the gas supplied to the gas space is 5[deg.]C or higher and 40[deg.]C or lower. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the HIP step is performed by heating at 800[deg.] C. or more and 1200[deg.] C. or less. 7. The method of manufacturing a member for nuclear power equipment according to claim 6 , wherein the heating is performed by raising the temperature of the defined space at a rate of 2[deg.]C/min or more and 10[deg.]C/min or less. including a first pressure adjustment step of making the pressure of the defined space higher than the pressure of the gas space after the placement step and before the filling step;
3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the filling step is performed in a state where the pressure in the defined space is higher than the pressure in the gas space. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, further comprising a second pressure adjustment step of depressurizing the defined space after the filling step and before the HIP step. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the defining member is a metal foil. 3. The method of manufacturing a member for nuclear power equipment according to claim 1, wherein the filling step is performed by accommodating the metal raw material in the defined space in which the forged metal member is accommodated. A nuclear facility member comprising a first metal member and a second metal member joined to the first metal member via a metal sintered body,
A nuclear power equipment member, wherein a size of pores included in the metal sintered body is 50 nm or more and 200 nm or less in a cross section of the metal sintered body observed with an electron microscope. The nuclear equipment member according to claim 12 , wherein the metal sintered body has a porosity of 0.5% or less.

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