Shield pump water-lubricated bearing graphite tile material added with graphene and preparation method of shield pump water-lubricated bearing graphite tile material

Abstract

The invention belongs to the technical field of inorganic non-metal graphite sealing materials, and particularly relates to a shield pump water-lubricated bearing graphite tile material added with graphene and a preparation method of the shield pump water-lubricated bearing graphite tile material. In order to solve the problems that an existing graphite sealing ring preparation process is complex, and the performance of a wear-resistant material cannot meet more harsh use requirements, the preparation method comprises the following steps: uniformly mixing superfine coke powder, graphite powder and a functionalized graphene solution to obtain a mixture, heating the mixture, and then heating asphalt; the shielding pump water lubricated bearing graphite tile material added with the graphene is obtained by heating, mixing and kneading, crushing and grinding, three times of roasting, two times of asphalt impregnation and graphitization, the hardness and graphitization degree of a graphite matrix are improved, the strength of a graphite product is greatly improved, and the harsh use requirement for an existing graphite high-performance wear-resistant material is met.

Description

Technical Field

[0001] This invention belongs to the technical field of inorganic non-metallic graphite sealing materials, specifically relating to graphite tile materials for water-lubricated bearings of shielded pumps with added graphene and their preparation methods. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Water-lubricated bearings in high-temperature, high-pressure shielded pumps operate in high-pressure environments with radioactive media. Due to the low viscosity of water, the water film thickness is only 1 / 8 of the oil film thickness for the same load-bearing capacity. They primarily operate under conditions of minute gaps and boundary lubrication. Therefore, the performance of the water-lubricated bearing material is a key factor determining its service life and performance. Through the development of the AP / CAP series nuclear main pump bearings, the importance of independent research and development of high-life carbon graphite has become increasingly apparent. It can be said that the future of third-generation nuclear power depends on the main pump, the main pump depends on the bearing, and the bearing depends on graphite. If political, economic, or other factors prevent the import of bearing graphite materials, it will severely impact the manufacturing and delivery of AP and CAP series main pumps, further affecting the progress of the entire nuclear power plant project. Currently, the technical status of graphite materials for CAP series main pump bearings has been determined, and in recent years, the domestic carbon graphite industry has established a certain foundation, providing a basis for a new round of material application research on the localization of carbon graphite under the research and verification system formed by the CAP1400 major special project. The preparation of high-performance carbon graphite materials has significant technical and safety implications for ensuring the independent controllability of CAP equipment. Corresponding products can also be extended to key equipment in aviation, underwater engineering, and other fields. However, existing graphite material preparation technologies are complex and have poor yields. Graphite materials also have low hardness and graphitization, and their strength cannot meet the requirements of water-lubricated bearings in high-temperature and high-pressure shielded pumps. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a graphene-added shielded pump water-lubricated bearing graphite tile material and its preparation method.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a graphene-added shielded pump water-lubricated bearing graphite tile material, comprising the following steps:

[0007] S1. After thoroughly mixing ultrafine coke powder, graphite powder and functionalized graphene solution, a mixture is obtained. After heating the mixture, asphalt is added to the mixture, and then heated and kneaded. After cooling, the material is obtained.

[0008] S2. The material obtained in step S1 is crushed and ground to obtain pressed powder. The pressed powder is then subjected to isostatic pressing to obtain a blank.

[0009] S3. The blank obtained in step S2 is subjected to a first calcination, a first asphalt impregnation, a second calcination, a second asphalt impregnation, a third calcination, and graphitization treatment in sequence to obtain the graphene-added shielded pump water lubrication bearing graphite tile material.

[0010] In a second aspect, the present invention provides a graphene-added shielded pump water-lubricated bearing graphite tile material, which is obtained by the preparation method described in the first aspect.

[0011] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0012] This invention uses ultrafine coke powder (particle size ≤10μm) as the main raw material and functionalized graphene solution as an additive to improve the hardness and graphitization degree of the graphite matrix, significantly enhancing the strength of graphite products and meeting the increasingly stringent requirements for high-performance wear-resistant graphite materials. Furthermore, the calcination process provided in this application helps increase the yield by approximately 10%. Attached Figure Description

[0013] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0014] Figure 1 A schematic diagram illustrating the preparation process of the graphite tile material for the water-lubricated bearing of the shielded pump with added graphene, as described in this invention. Detailed Implementation

[0015] A first typical embodiment of the present invention provides a method for preparing a graphite tile material for a water-lubricated bearing of a shielded pump with added graphene, comprising the following steps:

[0016] S1. After thoroughly mixing ultrafine coke powder, graphite powder and functionalized graphene solution, a mixture is obtained. After heating the mixture, asphalt is added to the mixture, and then heated and kneaded. After cooling, the material is obtained.

[0017] S2. The material obtained in step S1 is crushed and ground to obtain pressed powder. The pressed powder is then subjected to isostatic pressing to obtain a blank.

[0018] S3. The blank obtained in step S2 is subjected to a first calcination, a first asphalt impregnation, a second calcination, a second asphalt impregnation, a third calcination, and graphitization treatment in sequence to obtain the graphene-added shielded pump water lubrication bearing graphite tile material.

[0019] In one or more embodiments of this implementation, the mass ratio of ultrafine coke powder to graphite powder is 80-90:20-10, the ultrafine coke powder has a particle size of less than 10 μm, and the graphite powder has a particle size of less than 45 μm.

[0020] In one or more embodiments of this implementation, the functionalized graphene includes sulfonated graphene; the mass concentration of the functionalized graphene solution is 9-11%, and the amount of functionalized graphene solution added is 4-6% of the total mass of ultrafine coke powder and graphite powder.

[0021] In one or more embodiments of this implementation, in step S1, when the mixture is heated to 100°C, asphalt is added to the mixture. The amount of asphalt added is 55-65% of the total mass of the mixture, the softening point of the asphalt is 70-100°C, and the residual carbon rate is 30-50 wt%.

[0022] In one or more embodiments of this implementation, the heating and mixing process involves heating and kneading for 1 hour until the material temperature reaches above 160°C, and then maintaining the temperature for another 1 hour of kneading.

[0023] In one or more embodiments of this implementation, in step S2, the particle size of the pressed powder is below 70 μm, and the pressure of the isostatic pressing process is 100-200 MPa.

[0024] In one or more embodiments of this implementation, in step S3, the conditions for the first, second, and third roasting processes are: heating to 1300°C at a heating rate of 10-15°C / h and holding for 2 hours.

[0025] In one or more embodiments of this implementation, in step S3, the conditions for the first and second asphalt impregnation treatments are: impregnation treatment with asphalt as the impregnating agent for 5-20 hours at a temperature of 150-300℃ and a pressure of 1-3MPa.

[0026] In one or more embodiments of this implementation, in step S3, the graphitization treatment conditions are: graphitization temperature of 2300-2500℃, and holding at that temperature for 4 hours.

[0027] In a second typical embodiment of the present invention, a graphene-added shielded pump water-lubricated bearing graphite tile material is obtained by the preparation method described in the first typical embodiment.

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0029] Example 1

[0030] like Figure 1 As shown, firstly, ultrafine coke powder with a particle size of less than 10 μm and graphite powder with a particle size of less than 45 μm are mixed at a ratio of 80 wt% ultrafine coke powder and 20 wt% graphite powder. Then, a sulfonated graphene solution with a mass concentration of 5% of the total mass of ultrafine coke powder and graphite powder is added and thoroughly mixed to obtain a mixture. The sulfonated graphene solution has a mass concentration of 10%. Then, asphalt with a softening point of 93℃ and a residual carbon content of 40 wt% is added to the mixture at a mass concentration of 60 wt%. When the temperature of the mixture reaches 100℃, asphalt is added to the mixture, and then the mixture is heated and kneaded for 1 hour until the temperature reaches above 160℃. The temperature is maintained and kneaded for another hour. After cooling, the final material is obtained.

[0031] The cooled mixture is crushed and ground to a particle size of less than 70 μm to form pressed powder. The pressed powder is then pressed into a blank under a pressure of 150 MPa to obtain the blank.

[0032] The obtained billet was subjected to a first firing, a first pitch impregnation, a second firing, a second pitch impregnation, a third firing, and graphitization treatment in sequence to obtain a graphene-added shielded pump water-lubricated bearing graphite tile material with a density of 1.90 g / cm³. 3 It has a Shore hardness of 72, a flexural strength greater than 50 MPa, and a compressive strength greater than 150 MPa.

[0033] The conditions for the first, second, and third roasting processes were as follows: heating to 1300℃ at a heating rate of 15℃ / h and holding at that temperature for 2 hours. The conditions for the first and second asphalt impregnation processes were as follows: impregnation with asphalt as the impregnating agent at a temperature of 300℃ and a pressure of 3MPa for 20 hours. The graphitization temperature was 2500℃, and the holding time was 4 hours.

[0034] Example 2

[0035] like Figure 1 As shown, firstly, ultrafine coke powder with a particle size of less than 10 μm and graphite powder with a particle size of less than 45 μm are mixed at a ratio of 80 wt% ultrafine coke powder and 20 wt% graphite powder. Then, a sulfonated graphene solution with a mass concentration of 5% of the total mass of ultrafine coke powder and graphite powder is added and thoroughly mixed to obtain a mixture. The sulfonated graphene solution has a mass concentration of 10%. Then, asphalt with a softening point of 93℃ and a residual carbon content of 40 wt% is added to the mixture at a mass concentration of 60 wt%. When the temperature of the mixture reaches 100℃, asphalt is added to the mixture, and then the mixture is heated and kneaded for 1 hour until the temperature reaches above 160℃. The temperature is maintained and kneaded for another hour. After cooling, the final material is obtained.

[0036] The cooled mixture is crushed and ground to a particle size of less than 70 μm to form pressed powder. The pressed powder is then pressed into a blank under a pressure of 150 MPa to obtain the blank.

[0037] The obtained billet was subjected to a first firing, a first pitch impregnation, a second firing, a second pitch impregnation, a third firing, and graphitization treatment in sequence to obtain a graphene-added shielded pump water-lubricated bearing graphite tile material with a density of 1.92 g / cm³. 3 The flexural strength is greater than 50 MPa, and the compressive strength is greater than 150 MPa.

[0038] The conditions for the first, second, and third roasting processes were as follows: heating to 1300℃ at a heating rate of 15℃ / h and holding at that temperature for 2 hours. The conditions for the first and second asphalt impregnation processes were as follows: impregnation with asphalt as the impregnating agent at a temperature of 200℃ and a pressure of 2MPa for 10 hours. The graphitization temperature was 2400℃, and the holding time was 4 hours.

[0039] Example 3

[0040] like Figure 1 As shown, firstly, ultrafine coke powder with a particle size of less than 10 μm and graphite powder with a particle size of less than 45 μm are mixed at a ratio of 80 wt% ultrafine coke powder and 20 wt% graphite powder. Then, a sulfonated graphene solution with a mass concentration of 5% of the total mass of ultrafine coke powder and graphite powder is added and thoroughly mixed to obtain a mixture. The sulfonated graphene solution has a mass concentration of 10%. Then, asphalt with a softening point of 93℃ and a residual carbon content of 40 wt% is added to the mixture at a mass concentration of 60 wt%. When the temperature of the mixture reaches 100℃, asphalt is added to the mixture, and then the mixture is heated and kneaded for 1 hour until the temperature reaches above 160℃. The temperature is maintained and kneaded for another hour. After cooling, the final material is obtained.

[0041] The cooled mixture is crushed and ground to a particle size of less than 70 μm to form pressed powder. The pressed powder is then pressed into a blank under a pressure of 150 MPa to obtain the blank.

[0042] The obtained billet was subjected to a first firing, a first pitch impregnation, a second firing, a second pitch impregnation, a third firing, and graphitization treatment in sequence to obtain a graphene-added shielded pump water-lubricated bearing graphite tile material with a density of 1.91 g / cm³. 3 It has a Shore hardness of 75, a flexural strength greater than 50 MPa, and a compressive strength greater than 150 MPa.

[0043] The conditions for the first, second, and third roasting processes were as follows: heating to 1300℃ at a heating rate of 10℃ / h and holding at that temperature for 2 hours. The conditions for the first and second asphalt impregnation processes were as follows: impregnation with asphalt as the impregnating agent at a temperature of 150℃ and a pressure of 1MPa for 5 hours. The graphitization temperature was 2300℃, and the holding time was 4 hours.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of preparing a graphene-added shielding pump water-lubricated bearing graphite tile material, characterized by, The preparation method comprises the following steps: S1, mixing superfine coke powder, graphite powder and functionalized graphene solution uniformly, obtaining a mixture, adding pitch to the mixture after heating the mixture, then heating and kneading, and obtaining a material after cooling; S2, crushing and grinding the material obtained in step S1, obtaining a powder, and performing isostatic pressing forming treatment on the powder to obtain a blank; S3, sequentially performing first roasting, first pitch impregnation, second roasting, second pitch impregnation, third roasting and graphitization treatment on the blank obtained in step S2 to obtain the graphene-added shielding pump water-lubricated bearing graphite tile material.

2. The production method according to claim 1, wherein The mass ratio of the superfine coke powder to the graphite powder is 80-90:20-10, the particle size of the superfine coke powder is less than 10 μm, and the particle size of the graphite powder is less than 45 μm.

3. The production method according to claim 1, wherein The functionalized graphene comprises sulfonated graphene, the mass concentration of the functionalized graphene solution is 9-11%, and the addition amount of the functionalized graphene solution is 4-6% of the total mass of the superfine coke powder and the graphite powder.

4. The production method according to claim 1, wherein In step S1, the pitch is added to the mixture when the mixture is heated to 100℃, the addition amount of the pitch is 55-65% of the total mass of the mixture, the softening point of the pitch is 70-100℃, and the carbon residue rate is 30-50 wt%.

5. The production method according to claim 1, wherein The heating and kneading treatment is performed for 1 h, the material temperature is increased to above 160℃, and the temperature is maintained for another 1 h of kneading.

6. The production method according to claim 1, wherein In step S2, the particle size of the powder is less than 70 μm, and the pressure of the isostatic pressing forming treatment is 100-200 MPa.

7. The production method according to claim 1, wherein In step S3, the first roasting, the second roasting and the third roasting are performed at a temperature increasing rate of 10-15℃ / h to 1300℃, and the temperature is maintained for 2 h.

8. The production method according to claim 1, wherein In step S3, the first pitch impregnation and the second pitch impregnation are performed at a temperature of 150-300℃ and a pressure of 1-3 MPa for 5-20 h with pitch as the impregnating agent.

9. The production method according to claim 1, wherein In step S3, the graphitization is performed at a temperature of 2300-2500℃ for 4 h.

10. A graphene added shielded pump water lubricated bearing graphite material characterized in that, The graphene-added shielding pump water-lubricated bearing graphite tile material is obtained by the preparation method in any one of claims 1-9.

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