Tungsten alloy column for nuclear power main pump, manufacturing process and flywheel structure

Abstract

The invention discloses a tungsten alloy column for a nuclear power main pump, a manufacturing process and a flywheel structure, and belongs to the technical field of nuclear power main pump devices. The structure comprises a tungsten column base material, and a stainless steel metal layer is arranged on the periphery of the outer side face of the tungsten column base material. According to the tungsten alloy column for the nuclear power main pump, the manufacturing process and the flywheel structure, the stainless steel metal layer is arranged on the outer side of the tungsten column base material, so that the corrosion resistance of the tungsten alloy column can be effectively improved, the defects of the tungsten alloy column in the prior art are further overcome, and the service life of a flywheel is prolonged; and the stable performance of the nuclear power main pump is facilitated.

Description

Technical Field

[0001] The present invention relates to a tungsten alloy column, a manufacturing process and a flywheel structure for a nuclear power main pump, belonging to the technical field of nuclear power main pump devices. Background Art

[0002] In order to increase the moment of inertia of the rotating components of the nuclear main pump rotor and extend the coast-down time after the pump is stopped to discharge the residual heat in the reactor core, high-quality flywheels are assembled on the main pump rotor components, and the flywheels generally use high-density heavy metal alloys.

[0003] Hot isostatic pressing process is to place the product in a sealed container, apply equal pressure in all directions to the product, and apply high temperature at the same time. Under the action of high temperature and high pressure, the product is sintered and densified.

[0004] With the application of materials and cost considerations, more and more high-density materials are embedded to improve the quality of the flywheel, as follows: The literature ("Discussion on the Structure and Design Requirements of the Flywheel of Nuclear Main Pumps", Shanghai Electric KSB and Electric Pump Valve Co., Ltd., 201306, Cui Haiyan, Li Tianbin) discloses a flywheel structure, and its structure discloses a structural design in which assembly holes are arranged on the flywheel structure and are matched with high-density tungsten steel rods (usually high-purity tungsten steel or depleted uranium materials). In actual application, based on the service environment of the nuclear power main pump structure, its specific structure will be greatly affected in terms of service life in application.

[0005] The doctoral thesis ("Optimal Design of the Flywheel Structure of Nuclear Main Pumps", Dalian University of Technology, Jiang Lu, 2018.06) discloses a hierarchical structural design, in which the flywheel structure is designed with multiple layers and tungsten alloy layers are added to solve the mass problem of the flywheel.

[0006] The master's thesis ("Strength Analysis and Structural Dimension Design of the Flywheel of the Shielded Nuclear Main Pump under Static Conditions", Dalian University of Technology, Xu Fangbin, 2019.05.19) also discloses a flywheel structure, and its structure discloses a structural design in which assembly holes are arranged on the flywheel structure and are matched with high-density tungsten steel rods (usually high-purity tungsten steel or depleted uranium materials).

[0007] In the above-mentioned publicly available documents, it shows that using tungsten alloy columns as the main mass-bearing part of the flywheel is a more common structure at present. However, in specific actual applications, especially in the field of nuclear power applications, it has an adverse effect on the tungsten alloy part, and its corrosion resistance effect is relatively weak. Of course, for the use of this structure, it is expected that the service life is as long as possible to further ensure the stability of the unit. Therefore, it is particularly important to further consider the design of the tungsten alloy column part. Summary of the Invention

[0008] The object of the present invention is to provide a tungsten alloy column, a manufacturing process and a flywheel structure for a nuclear power main pump. Tungsten-based heavy alloy is prone to corrosion in a special application environment and needs to be protected. An austenitic stainless steel layer is coated on its surface to improve its corrosion resistance.

[0009] The technical solution adopted by the present invention is as follows: A manufacturing process for a tungsten alloy column for a nuclear power main pump, characterized by comprising the following steps: S1, manufacturing of tungsten column: Using tungsten metal material to manufacture tungsten column according to the target size requirements to form a tungsten column substrate; S2, manufacturing of tungsten alloy column: Placing the tungsten column substrate into a manufacturing mold, and coating a stainless steel metal layer on the outer side surface of the tungsten column substrate to form a tungsten alloy column; S3, inspecting the geometric dimensions of the tungsten alloy column bar, and combining finish machining to make the geometric dimensions of the final tungsten alloy column bar meet the requirements.

[0010] Further, in step 2, when coating the stainless steel metal layer on the outer side surface of the tungsten column substrate, the casting process is adopted to completely wrap the tungsten column substrate with the stainless steel metal.

[0011] Further, in step 2, when coating the stainless steel metal layer on the outer side surface of the tungsten column substrate, the hot isostatic pressing process is adopted to completely wrap the tungsten column substrate with the stainless steel metal.

[0012] Further, the hot isostatic pressing process is that the product is placed in a closed container, and while applying an isotropic pressure to the product, high temperature is applied. Under the combined action of high temperature and high pressure, the product is sintered, densified or diffusion bonded.

[0013] Further, before the tungsten column substrate is placed into the closable container, stainless steel metal powder is laid at the bottom, the tungsten column substrate is placed in, and then stainless steel metal powder is continuously added to completely wrap the tungsten column substrate with the stainless steel metal powder.

[0014] A tungsten alloy column for a nuclear power main pump, manufactured and formed by using the above-mentioned manufacturing process for a tungsten alloy column for a nuclear power main pump, including a tungsten column substrate, and a layer of stainless steel metal layer is disposed around the outer side surface of the tungsten column substrate.

[0015] Further, the stainless steel metal layer is integrally formed.

[0016] A flywheel for a nuclear power main pump, including a flywheel body, an assembly hole is provided on the flywheel body, and the above-mentioned tungsten alloy column for a nuclear power main pump is assembled in the assembly hole.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. A tungsten alloy column, manufacturing process and flywheel structure for a nuclear power main pump according to the present invention can effectively improve the corrosion resistance of the tungsten alloy column by providing a stainless steel metal layer on the outer side of the tungsten column substrate, further improving the deficiencies of the tungsten alloy column in the prior art, extending the service life of the flywheel, and being more conducive to the stable performance of the nuclear power main pump. 2. A tungsten alloy column, manufacturing process and flywheel structure for a nuclear power main pump according to the present invention have the advantages of high connection strength, complete microstructure, small distortion, and the ability to connect different materials due to the use of hot isostatic pressing diffusion bonding technology for the tungsten alloy column. Since no liquid phase is generated at the interface, the interface bonding strength is the same as that of the weaker side base material, enabling good metallurgical bonding and forming a high-density composite tungsten alloy column. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described by way of examples with reference to the accompanying drawings, where: Figure 1 is a schematic structural diagram of the tungsten alloy column of the present invention; Figure 2 is a manufacturing process diagram of the tungsten alloy column of the present invention.

[0019] Reference numerals in the figures: 1 - tungsten column substrate, 2 - stainless steel metal layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] All features disclosed in this specification, or all steps in any method or process disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.

[0021] Any feature disclosed in this specification, unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example of a series of equivalent or similar features.

[0022] Example 1 A manufacturing process for a tungsten alloy column for a nuclear power main pump, as Figure 1 and Figure 2 shown, includes the following steps: S1. Manufacturing of the tungsten column. Using tungsten metal material, a tungsten column is formed according to the target size requirements to form the tungsten column substrate 1. S2. Manufacturing of the tungsten alloy column. The tungsten column substrate 1 is placed in a manufacturing mold, and a stainless steel metal layer 2 is coated on the outer side of the tungsten column substrate 1 to form the tungsten alloy column. S3. Inspecting the geometric dimensions of the tungsten alloy column bar and performing finishing to make the geometric dimensions of the final tungsten alloy column bar meet the requirements.

[0023] A manufacturing process for a tungsten alloy column used in a nuclear power main pump. In terms of structural design, different from the traditional structure, the effect of using a tungsten column substrate 1 and a stainless steel metal layer 2 in this structure is adopted. A protective layer is effectively coated on the outer side of the tungsten column substrate 1, solving the problem that tungsten-based heavy alloys are prone to corrosion and need protection in special application environments, thus achieving a longer service life of the flywheel, and further improving the service life of the flywheel and the stability of the entire nuclear power main pump.

[0024] In the above specific process design, as a specific design, in step 2, when coating the stainless steel metal layer 2 on the outer side of the tungsten column substrate 1, the casting process is used to completely wrap the tungsten column substrate 1 with stainless steel metal.

[0025] As a different design and more suitable for the requirements of this design, in step 2, when coating the stainless steel metal layer 2 on the outer side of the tungsten column substrate 1, the hot isostatic pressing process is used to completely wrap the tungsten column substrate 1 with stainless steel metal.

[0026] As a specific description, the hot isostatic pressing process is that the product is placed in a sealed container, and while applying an isotropic pressure to the product, high temperature is applied. Under the combined action of high temperature and high pressure, the product is sintered, densified or diffusion bonded.

[0027] Furthermore, before the tungsten column substrate 1 is placed into the sealable container, stainless steel metal powder is laid at the bottom, the tungsten column substrate 1 is placed in, and then stainless steel metal powder is continuously added to completely wrap the tungsten column substrate 1.

[0028] In the design of this process, the tungsten alloy column adopting the hot isostatic pressing diffusion bonding technology has the advantages of high connection strength, complete microstructure, small distortion, and the ability to achieve connection between different materials. Since no liquid phase is generated at the interface, the interface bonding strength is the same as that of the weak-side base material, and good metallurgical bonding can be achieved, forming a high-density composite tungsten alloy column.

[0029] Example 2 A tungsten alloy column for a nuclear power main pump is formed by using the manufacturing process of a tungsten alloy column for a nuclear power main pump described in Example 1, and includes a tungsten column substrate 1. A layer of stainless steel metal layer 2 is provided around the outer side of the tungsten column substrate 1.

[0030] As a more specific design, the stainless steel metal layer 2 is integrally formed.

[0031] Example 3 A flywheel for a nuclear power main pump includes a flywheel body. An assembly hole is provided on the flywheel body, and a tungsten alloy column for a nuclear power main pump described in Example 2 is assembled in the assembly hole.

[0032] In summary: 1. For the tungsten alloy column, manufacturing process and flywheel structure for nuclear power main pumps of the present invention, by providing a stainless steel metal layer on the outer side of the tungsten column substrate, the corrosion resistance of the tungsten alloy column can be effectively improved, further improving the deficiencies of the tungsten alloy column in the prior art, enhancing the service life of the flywheel, and being more conducive to the stable performance of the nuclear power main pump; 2. For the tungsten alloy column, manufacturing process and flywheel structure for nuclear power main pumps of the present invention, the tungsten alloy column using the hot isostatic pressing diffusion bonding technology has the advantages of high bonding strength, complete microstructure, small distortion, and the ability to achieve bonding between different materials. Since no liquid phase is generated at the interface, the interface bonding strength is the same as that of the weaker side base material, and good metallurgical bonding can be achieved to form a high-density composite tungsten alloy column.

[0033] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. A manufacturing process of a tungsten alloy column for a nuclear power main pump, characterized in that: The following steps are involved: S1, manufacturing of tungsten column, using metal tungsten material to mold the tungsten column according to the target size requirements to form a tungsten column substrate; S2, making a tungsten alloy column, placing a tungsten column substrate into a manufacturing mold, and coating the outer side of the tungsten column substrate with a layer of stainless steel metal layer, thereby forming a tungsten alloy column; S3, check the geometric dimensions of the tungsten alloy column and rod, and combine it with fine processing to make the final geometric dimensions of the tungsten alloy column and rod meet the requirements.

2. The manufacturing process of a tungsten alloy column for a nuclear power main pump according to claim 1, characterized in that: In step 2, when the stainless steel metal layer is coated on the outer side of the tungsten column substrate, a casting process is used to make the stainless steel metal completely wrap the tungsten column substrate.

3. The manufacturing process of a tungsten alloy column for a nuclear power main pump according to claim 1, characterized in that: In step 2, when the stainless steel metal layer is coated on the outer side of the tungsten column substrate, a hot isostatic pressing process is used to make the stainless steel metal completely wrap the tungsten column substrate.

4. The manufacturing process of a tungsten alloy column for a nuclear power main pump as claimed in claim 3, characterized in that: The hot isostatic pressing process is to place the product in a closed container, apply equal pressure in all directions to the product and apply high temperature at the same time, so that the product can be sintered, densified or diffusion-connected under the combined action of high temperature and high pressure.

5. The manufacturing process of a tungsten alloy column for a nuclear power main pump as claimed in claim 4, characterized in that: Before the tungsten column substrate is placed in a sealable container, stainless steel metal powder is laid on the bottom, the tungsten column substrate is placed in, and then stainless steel metal powder is continued to be added, and the stainless steel metal powder is completely wrapped around the tungsten column substrate.

6. A tungsten alloy column for a nuclear power main pump, manufactured by the manufacturing process of a tungsten alloy column for a nuclear power main pump according to any one of claims 1 to 5, characterized in that: It comprises a tungsten column substrate, and a stainless steel metal layer is arranged around the outer side surface of the tungsten column substrate.

7. A tungsten alloy column for a nuclear power main pump as claimed in claim 6, characterized in that: The stainless steel metal layer is integrally formed.

8. A flywheel structure for a nuclear power main pump, characterized in that: It comprises a flywheel body, wherein the flywheel body is provided with an assembly hole, and a tungsten alloy column for a nuclear power main pump as claimed in any one of claims 6 to 7 is assembled in the assembly hole.

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