Composite valve and manufacturing method thereof

Abstract

The invention discloses a composite valve and a manufacturing method thereof, and belongs to the technical field of valves. The first alloy material, the tantalum metal coated with the nickel and the cobalt and the second alloy material are compounded through vacuum diffusion welding, and a valve body, a valve cover, a valve rod and a valve clack are manufactured after machining; and compounding the third alloy material, the fourth alloy material and the nano silicon carbide-nano molybdenum disulfide composite material through a hot isostatic pressing process to prepare the wear-resistant alloy. Further cladding the prepared wear-resistant alloy on the surfaces of the valve rod and the valve clack through a laser cladding process; and finally, all the parts are machined and assembled to obtain the composite valve. The composite valve can effectively resist erosion of corrosive media, can bear stress under high-temperature and high-pressure working conditions, and can effectively resist erosion and abrasion of the media.

Description

Technical Field

[0001] This application relates to the technical field of valves, and particularly to a composite valve and its manufacturing method. Background Art

[0002] Valves are indispensable fluid control devices in industrial pipeline systems and are widely used in industries such as petroleum, chemical, power, and metallurgy. Traditional valves are usually made of a single metal material, such as carbon steel, stainless steel, alloy steel, etc. However, in harsh working conditions such as high temperature, high pressure, and strongly corrosive media, a single metal material often fails to meet the usage requirements of valves. For example, carbon steel valves are easily corroded in corrosive media, while stainless steel valves lack strength under high temperature and high pressure. Therefore, how to improve the corrosion resistance, wear resistance, and strength of valves has become an important topic in the field of valve technology. In the prior art, surface treatment processes such as surfacing and spraying have problems of low bonding strength and easy peeling. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, this application provides a composite valve and its manufacturing method. The first alloy material, tantalum metal coated with nickel and cobalt, and the second alloy material are compounded by vacuum diffusion welding, and after processing, a valve body, a valve cover, a valve stem, and a valve disc are obtained; then the third alloy material, the fourth alloy material, and the nano-silicon carbide - nano-molybdenum disulfide composite material are compounded by hot isostatic pressing to obtain a wear-resistant alloy; further, the obtained wear-resistant alloy is laser cladded on the surfaces of the valve stem and the valve disc; finally, after processing and assembling each component, a composite valve is obtained. This composite valve can effectively resist the erosion of corrosive media, can withstand the stress under high temperature and high pressure working conditions, and can also effectively resist the erosion and wear of the media.

[0004] To achieve the above object, this application adopts the following technical solutions: In a first aspect, this application provides a composite valve, including a valve body, a valve cover provided on the valve body, a valve stem passing through the valve cover and extending into the inner cavity of the valve body, and a valve disc with one side closely fitting the end of the valve stem extending into the inner cavity of the valve body and the other side closely fitting the valve body; the materials of the valve body, the valve cover, the valve stem, and the valve disc are all valve composite materials; the valve composite materials all include a first alloy material, tantalum metal coated with nickel and cobalt, and a second alloy material; the outermost surfaces of the valve stem and the valve disc are also covered with a wear-resistant alloy; the wear-resistant alloy includes a third alloy material, a nano-silicon carbide - nano-molybdenum disulfide composite material, and a fourth alloy material from the inside to the outside.

[0005] In a second aspect, this application provides a manufacturing method of a composite valve, including the following steps: Ultrasonically treat the first alloy material, tantalum metal coated with nickel and cobalt, the second alloy material, the third alloy material, the nano-silicon carbide - nano-molybdenum disulfide composite material, and the fourth alloy material with ethanol for 0.5 - 1 h to remove surface oil stains; Under the condition of 800 - 1200 °C, use the method of vacuum diffusion welding to composite the first alloy material, tantalum metal coated with nickel and cobalt, and the second alloy material together, and keep the temperature and pressure for 2 - 4 h to obtain the valve composite material; Mechanically process and form the valve composite material to obtain the valve body, valve cover, valve stem, and valve flap; Under the conditions of 1200 - 1500 °C and 100 - 200 Mpa, composite the third alloy material, the fourth alloy material, and the nano-silicon carbide - nano-molybdenum disulfide composite material together by hot isostatic pressing process, and keep the temperature and pressure for 1 - 3 h to prepare the wear-resistant alloy; Under the conditions of argon protection, laser power of 2 - 5 kW, and powder feeding rate of 5 - 20 g / min, clad the wear-resistant alloy onto the outermost surfaces of the valve stem and valve flap by laser cladding process; Grind, polish and assemble the prepared components to obtain the composite valve.

[0006] Beneficial technical effects: During the vacuum diffusion welding process, in the tantalum metal coated with nickel and cobalt, the nickel and cobalt coated on the tantalum metal diffuse under the high-temperature condition of vacuum diffusion welding, and form a diffusion layer with the first alloy material and the second alloy material, enhancing the interfacial bonding strength; while the coated tantalum metal is protected, so that the vast majority of tantalum metal remains in its original state without chemical reaction and other changes, thereby inhibiting the intergranular corrosion caused by the diffusion of carbon element at high temperature, and greatly improving the corrosion resistance of the valve composite material. At the same time, in the prepared wear-resistant alloy, the nano-silicon carbide - nano-molybdenum disulfide composite material also diffuses under the high-temperature and high-pressure conditions of the hot isostatic pressing process, and forms a diffusion layer with the first alloy material and the second alloy material, enhancing the interfacial bonding strength of the wear-resistant alloy. Further cladding the wear-resistant alloy onto the outermost surfaces of the valve stem and valve flap ensures the sealing performance at the valve stem and valve flap, and at the same time greatly enhances the wear resistance at the valve stem and valve flap, meeting the fluid sealing and control requirements in extreme environments such as petrochemical, nuclear power, and deep-sea equipment. Description of the drawings

[0007] Figure 1 is a schematic structural diagram of the composite valve.

[0008] Figure 2 is a schematic process flow diagram for preparing the composite valve.

[0009] Figure 3 is a schematic principle diagram for forming the valve composite material.

[0010] Reference numerals: 1, valve body; 2, valve cover; 3, valve stem; 4, valve disc. Detailed implementation manners

[0011] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the following further details this application in combination with embodiments. However, this should not be construed as limiting the scope of this application to the following examples. Without departing from the above method idea of this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0012] In this application, the terms used are only for the purpose of describing specific embodiments and are not intended to limit this application. If terms such as "first" and "second" appear, they are only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0013] In a first aspect, this application provides a composite valve, the structure of which is as Figure 1 shown, including a valve body 1, a valve cover 2 provided on the valve body 1, a valve stem 3 passing through the valve cover 2 and extending into the inner cavity of the valve body 1, and a valve disc 4 with one side closely attached to one end of the valve stem 3 extending into the inner cavity of the valve body 1 and the other side closely attached to the valve body 1; the valve body 1, valve cover 2, valve stem 3 and valve disc 4 are all made of valve composite materials; the valve composite materials all include a first alloy material, tantalum metal coated with nickel and cobalt, and a second alloy material; the outermost surfaces of the valve stem 3 and valve disc 4 are also covered with wear-resistant alloys; the wear-resistant alloy includes a third alloy material, a nano-silicon carbide-nano-molybdenum disulfide composite material and a fourth alloy material from the inside to the outside.

[0014] In a possible implementation manner, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is (20~30):(20~30):(40~60).

[0015] In a possible implementation manner, the first alloy material includes any one of 316L stainless steel, 317L stainless steel and Inconel 625 nickel-based alloy.

[0016] In a possible implementation manner, the second alloy material includes any one of Q295 high-strength low-alloy steel and Q345 high-strength low-alloy steel.

[0017] In a possible implementation manner, the thickness ratio of the first alloy material, the tantalum metal coated with nickel and cobalt, and the second alloy material is (30~40):(1~3):(55~70). At such a thickness ratio, the interface bonding strength and corrosion resistance of the obtained valve composite material are better.

[0018] In a possible implementation manner, the third alloy material includes any one of Inconel 718 nickel-based alloy and ALLOY420 nickel-based alloy; the thickness of the third alloy material is 1-3 mm.

[0019] In a possible implementation manner, the fourth alloy material includes any one of Stellite6 cobalt-based alloy and Stellite6B cobalt-based alloy; the thickness of the fourth alloy material is 1-2 mm.

[0020] In a possible implementation manner, the nano-silicon carbide - nano-molybdenum disulfide composite material includes nano-silicon carbide, nano-molybdenum disulfide and a silane coupling agent; the mass ratio of nano-silicon carbide, nano-molybdenum disulfide and the silane coupling agent is (30-50):(48-68):(1-3); the thickness of the nano-silicon carbide - nano-molybdenum disulfide composite material is 50-100 nm.

[0021] In a possible implementation manner, the nano-silicon carbide can be replaced by nano-aluminum oxide or nano-zirconia.

[0022] In a possible implementation manner, the interfacial bonding strength of the valve composite material is ≥300 Mpa, and the surface roughness Ra ≤ 0.8 μm.

[0023] In a second aspect, the present application provides a manufacturing method of a composite valve, as Figure 2 shown, including the following steps: Ultrasonically clean the first alloy material, tantalum metal coated with nickel and cobalt, the second alloy material, the third alloy material, the nano-silicon carbide - nano-molybdenum disulfide composite material and the fourth alloy material with ethanol for 0.5-1 h to remove surface oil stains; Under the condition of 800-1200 °C, use the method of vacuum diffusion welding to composite the first alloy material, tantalum metal coated with nickel and cobalt and the second alloy material together, and keep the temperature and pressure for 2-4 h to obtain a valve composite material. The principle of this process is as Figure 3 shown; Mechanically process and form the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3 and a valve disc 4; Under the conditions of 1200-1500 °C and 100-200 Mpa, composite the third alloy material, the nano-silicon carbide - nano-molybdenum disulfide composite material and the fourth alloy material together by hot isostatic pressing process, and keep the temperature and pressure for 1-3 h to prepare a wear-resistant alloy; Under the conditions of argon protection, a laser power of 2-5 kW and a powder feeding rate of 5-20 g / min, clad the wear-resistant alloy on the outermost surface of the valve stem 3 and the valve disc 4 by laser cladding process; After grinding, polishing and assembling the prepared components, a composite valve is obtained.

[0024] The following will specifically describe a composite valve and its manufacturing method provided by the present application in combination with different embodiments.

[0025] Embodiment 1: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Place 316L stainless steel, tantalum metal coated with nickel and cobalt, Q295 high-strength low-alloy steel, Inconel 718 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6 cobalt-based alloy in ethanol and ultrasonically clean for 0.5 h to remove surface oil stains; 2. Under the condition of 800 °C, use the method of vacuum diffusion welding to composite 316L stainless steel, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel together, and keep the temperature and pressure for 2 h to obtain a valve composite material; In the above steps 1 - 2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt, and tantalum is 20:20:60; 3. Machine the valve composite material into a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4; 4. Under the conditions of 1200 °C and 100 Mpa, composite Inconel 718 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6 cobalt-based alloy together by hot isostatic pressing process, keep the temperature and pressure for 1 h to obtain a wear-resistant alloy, wherein the mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent is 35:64:1; 5. Under the conditions of argon protection, a laser power of 2 kW, and a powder feeding rate of 5 g / min, clad the wear-resistant alloy onto the outermost surfaces of the valve stem 3 and the valve disc 4 by laser cladding process; 6. After grinding, polishing and assembling the prepared components, a composite valve is obtained.

[0026] Embodiment 2: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Place 317L stainless steel, tantalum metal coated with nickel and cobalt, Q345 high-strength low-alloy steel, ALLOY 420 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6B cobalt-based alloy in ethanol and ultrasonically clean for 0.8 h to remove surface oil stains; 2. Under the condition of 1000 °C, using the method of vacuum diffusion welding, 317L stainless steel, tantalum metal coated with nickel and cobalt, and Q345 high-strength low-alloy steel are compounded together, and heat preservation and pressure holding are carried out for 3 h to obtain valve composite material; In the above steps 1-2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is 25:25:50; 3. The valve composite material is machined and formed to obtain a valve body 1, a valve cover 2, a valve stem 3 and a valve flap 4; 4. Under the conditions of 1350 °C and 150 Mpa, ALLOY 420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6B cobalt-based alloy are compounded together by hot isostatic pressing process, and heat preservation and pressure holding are carried out for 2 h to obtain wear-resistant alloy, wherein the mass ratio of nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent is 43:55:2; 5. Under the conditions of argon protection, laser power of 3.5 kW and powder feeding rate of 10 g / min, the wear-resistant alloy is laser-clad on the outermost surfaces of the valve stem 3 and the valve flap 4; 6. The prepared components are polished and assembled to obtain a composite valve.

[0027] Example 3: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Put Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, Q295 high-strength low-alloy steel, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6 cobalt-based alloy into ethanol and ultrasonically treat for 1 h to remove surface oil stains; 2. Under the condition of 1200 °C, using the method of vacuum diffusion welding, Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt and Q295 high-strength low-alloy steel are compounded together, and heat preservation and pressure holding are carried out for 4 h to obtain valve composite material; In the above steps 1-2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is 30:30:40; 3. The valve composite material is machined and formed to obtain a valve body 1, a valve cover 2, a valve stem 3 and a valve flap 4; 4. Under the conditions of 1500 °C and 200 Mpa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6 cobalt-based alloy are compounded together by hot isostatic pressing process, and heat preservation and pressure holding are carried out for 3 h to obtain wear-resistant alloy, wherein the mass ratio of nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent is 38:59:3; 5. Under the condition of argon protection, a laser power of 5 kW, and a powder feeding rate of 20 g / min, the wear-resistant alloy is cladded onto the outermost surfaces of the valve stem 3 and the valve disc 4 through the laser cladding process; 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0028] Example 4: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Place 316L stainless steel, tantalum metal coated with nickel and cobalt, Q345 high-strength low-alloy steel, ALLOY 420 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6B cobalt-based alloy in ethanol and ultrasonically clean for 0.6 h to remove surface oil stains; 2. Under the condition of 900 °C, use the method of vacuum diffusion welding to composite 316L stainless steel, tantalum metal coated with nickel and cobalt, and Q345 high-strength low-alloy steel together, and keep the temperature and pressure for 2.5 h to obtain a valve composite material; In the above steps 1 - 2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt, and tantalum is 20:20:60; 3. Machine the valve composite material into shape to obtain the valve body 1, valve cover 2, valve stem 3, and valve disc 4; 4. Under the conditions of 1250 °C and 120 Mpa, use the hot isostatic pressing process to composite ALLOY 420 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6B cobalt-based alloy together, and keep the temperature and pressure for 1.5 h to obtain a wear-resistant alloy, where the mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent is 40:58:2; 5. Under the condition of argon protection, a laser power of 3 kW, and a powder feeding rate of 15 g / min, the wear-resistant alloy is cladded onto the outermost surfaces of the valve stem 3 and the valve disc 4 through the laser cladding process; 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0029] Example 5: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Place 317L stainless steel, tantalum metal coated with nickel and cobalt, Q295 high-strength low-alloy steel, Inconel 718 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6 cobalt-based alloy in ethanol and ultrasonically clean for 0.9 h to remove surface oil stains; 2. Under the condition of 1100 °C, using the method of vacuum diffusion welding, 317L stainless steel, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel are compounded together, and heat and pressure are maintained for 3.5 h to obtain valve composite material; In the above steps 1-2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is 28:22:50; 3. The valve composite material is machined and formed to obtain a valve body 1, a valve cover 2, a valve stem 3 and a valve flap 4; 4. Under the conditions of 1400 °C and 180 Mpa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6 cobalt-based alloy are compounded together by hot isostatic pressing process, and heat and pressure are maintained for 2.5 h to prepare wear-resistant alloy. Among them, the mass ratio of nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent is 32:66:2; 5. Under the conditions of argon protection, a laser power of 4 kW and a powder feeding rate of 18 g / min, the wear-resistant alloy is laser-clad on the outermost surfaces of the valve stem 3 and the valve flap 4; 6. The prepared components are polished and assembled to obtain a composite valve.

[0030] Example 6: As Figure 2 shown, a manufacturing method of a composite valve includes the following steps: 1. Put Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, Q345 high-strength low-alloy steel, ALLOY420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6B cobalt-based alloy into ethanol and ultrasonically clean for 0.7 h to remove surface oil stains; 2. Under the condition of 1050 °C, using the method of vacuum diffusion welding, Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt and Q345 high-strength low-alloy steel are compounded together, and heat and pressure are maintained for 3 h to obtain valve composite material; In the above steps 1-2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is 24:26:50; 3. The valve composite material is machined and formed to obtain a valve body 1, a valve cover 2, a valve stem 3 and a valve flap 4; 4. Under the conditions of 1300 °C and 160 Mpa, ALLOY 420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite6B cobalt-based alloy are compounded together by hot isostatic pressing process, and heat and pressure are maintained for 2 h to prepare wear-resistant alloy. Among them, the mass ratio of nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent is 49:49:2; 5. Under the conditions of argon protection, a laser power of 3.5 kW, and a powder feeding rate of 12 g / min, the wear-resistant alloy is cladded onto the outermost surfaces of the valve stem 3 and the valve disc 4 through the laser cladding process; 6. Grind, polish and assemble the prepared components to obtain the composite valve.

[0031] Comparative Example 1: A manufacturing method of a composite valve, comprising the following steps: 1. Place 316L stainless steel, tantalum metal, Q295 high-strength low-alloy steel, Inconel 718 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6 cobalt-based alloy in ethanol and ultrasonically treat for 0.5 h to remove surface oil stains; 2. Under the condition of 800 °C, use the method of vacuum diffusion welding to composite 316L stainless steel, tantalum metal, and Q295 high-strength low-alloy steel together, and keep the temperature and pressure for 2 h to obtain the valve composite material; 3. Machine the valve composite material into shape to obtain the valve body 1, valve cover 2, valve stem 3, and valve disc 4; 4. Under the conditions of 1200 °C and 100 Mpa, composite Inconel 718 nickel-based alloy, nano-silicon carbide - nano-molybdenum disulfide composite material, and Stellite6 cobalt-based alloy together through the hot isostatic pressing process, keep the temperature and pressure for 1 h to prepare the wear-resistant alloy, wherein the mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent is 35:64:1; 5. Under the conditions of argon protection, a laser power of 2 kW, and a powder feeding rate of 5 g / min, the wear-resistant alloy is cladded onto the outermost surfaces of the valve stem 3 and the valve disc 4 through the laser cladding process; 6. Grind, polish and assemble the prepared components to obtain the composite valve.

[0032] Comparative Example 2: A manufacturing method of a composite valve, comprising the following steps: 1. Place Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel in ethanol and ultrasonically treat for 1 h to remove surface oil stains; 2. Under the condition of 1200 °C, use the method of vacuum diffusion welding to composite Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel together, and keep the temperature and pressure for 4 h to obtain the valve composite material; In the above steps 1 - 2, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt, and tantalum is 30:30:40; 3. Machine the valve composite material into shape to obtain the valve body 1, valve cover 2, valve stem 3, and valve disc 4; 4. Grind, polish and assemble the prepared components to obtain a composite valve.

[0033] Comparative Example 3: A manufacturing method of a composite valve, comprising the following steps: 1. Place Inconel 625 nickel-based alloy, tantalum metal and Q345 high-strength low-alloy steel in ethanol and ultrasonically clean for 0.7 h to remove surface oil stains; 2. Under the condition of 1050 °C, use the method of vacuum diffusion welding to bond Inconel 625 nickel-based alloy, tantalum metal and Q345 high-strength low-alloy steel together, and keep the temperature and pressure for 3 h to obtain a valve composite material; 3. Machine the valve composite material into a valve body 1, a valve cover 2, a valve stem 3 and a valve flap 4; 4. Grind, polish and assemble the prepared components to obtain a composite valve.

[0034] Performance test: Refer to CJ / T 192-2017, through the combined strength shear test, use a material testing machine, and measure the interfacial bonding strength of the prepared composite valve under the test tensile rate of 3.0 mm / min.

[0035] Refer to GB / T 24196-2009, through the electrochemical test method, test the corrosion potential and corrosion current of the prepared composite valve to effectively evaluate the corrosion resistance of the composite valve.

[0036] Refer to GB / T 24196-2009, through the wear test method, test the volume wear rate at the valve stem and valve flap of the prepared composite valve to effectively evaluate the wear resistance of the composite valve.

[0037] The above test results are statistically shown in Table 1 below: Table 1 Performance test results of composite valves prepared in examples and comparative examples

[0038] As can be seen from Table 1, the wear resistance, interfacial bonding performance and corrosion resistance of Examples 1-6 are all better than those of Comparative Examples 1-3.

[0039] The reason is that in Examples 1 to 6, during the vacuum diffusion welding process, in the tantalum metal coated with nickel and cobalt, the nickel and cobalt coated on the tantalum metal diffuse under the high-temperature conditions of vacuum diffusion welding, forming a diffusion layer with the first alloy material and the second alloy material, enhancing the interfacial bonding strength; while the coated tantalum metal will be protected, so that the vast majority of tantalum metal maintains its original state without chemical reaction and other changes, thereby inhibiting the intergranular corrosion caused by the diffusion of carbon elements at high temperature and greatly improving the corrosion resistance of the valve composite material. At the same time, in the prepared wear-resistant alloy, the nano-silicon carbide - nano-molybdenum disulfide composite material will also diffuse under the high-temperature and high-pressure conditions of the hot isostatic pressing process, forming a diffusion layer with the first alloy material and the second alloy material, enhancing the interfacial bonding strength of the wear-resistant alloy. Further cladding the wear-resistant alloy on the outermost surface of the valve stem and the valve disc ensures the sealing performance at the valve stem and the valve disc, and at the same time greatly enhances the wear resistance at the valve stem and the valve disc.

[0040] In Comparative Example 1, the tantalum metal surface is not coated with nickel and cobalt, so it is impossible to form a diffusion layer with the first alloy material and the second alloy material, resulting in a significant reduction in the interfacial bonding strength; also for this reason, the tantalum metal will be affected by temperature during the vacuum diffusion welding process and change, resulting in a significant reduction in the effect of inhibiting the diffusion of carbon elements at high temperature, so it is more likely to produce intergranular corrosion and reduce the corrosion resistance of the valve.

[0041] In Comparative Example 2, since the wear-resistant alloy is not further clad on the outermost surface of the valve stem and the valve disc, the wear resistance at the valve stem and the valve disc is significantly reduced.

[0042] In Comparative Example 3, the tantalum metal surface is not coated with nickel and cobalt, and at the same time the wear-resistant alloy is not further clad on the outermost surface of the valve stem and the valve disc, so the performance of the prepared valve is the worst in all aspects.

[0043] The above results show and describe the basic principles, main features and advantages of the present application.

[0044] Those skilled in the art of this industry should understand that the present application is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present application. Without departing from the spirit and scope of the present application, the present application will have various changes and improvements, and these changes and improvements all fall within the scope of the present application claimed. The scope of protection of the present application is defined by the equivalents of the appended claims.

Claims

1. A composite valve, characterized in that, It includes a valve body (1), a valve cover (2) provided on the valve body (1), a valve stem (3) passing through the valve cover (2) and extending into the inner chamber of the valve body (1), and a valve flap (4) with one side closely attached to one end of the valve stem (3) extending into the inner chamber of the valve body (1) and the other side closely attached to the valve body (1); the materials of the valve body (1), valve cover (2), valve stem (3), and valve flap (4) are all valve composite materials; the valve composite materials all include a first alloy material, tantalum metal coated with nickel and cobalt, and a second alloy material; the outermost surfaces of the valve stem (3) and valve flap (4) are also covered with wear-resistant alloy; the wear-resistant alloy includes a third alloy material, a nano-silicon carbide - nano-molybdenum disulfide composite material, and a fourth alloy material from the inside to the outside.

2. The composite valve according to claim 1, characterized in that, In the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt, and tantalum is (20~30):(20~30):(40~60).

3. A composite valve according to claim 1, characterized in that, The first alloy material includes any one of 316L stainless steel, 317L stainless steel, and Inconel 625 nickel-based alloy.

4. A composite valve according to claim 1, characterized in that, The second alloy material includes any one of Q295 high-strength low-alloy steel and Q345 high-strength low-alloy steel.

5. A composite valve according to claim 1, characterized in that, The thickness ratio of the first alloy material, tantalum metal coated with nickel and cobalt, and the second alloy material is (30~40):(1~3):(55~70).

6. A composite valve according to claim 1, characterized in that, The third alloy material includes any one of Inconel718 nickel-based alloy and ALLOY 420 nickel-based alloy; the thickness of the third alloy material is 1~3 mm.

7. A composite valve according to claim 1, characterized in that, The fourth alloy material includes any one of Stellite6 cobalt-based alloy and Stellite6B cobalt-based alloy; the thickness of the fourth alloy material is 1~2 mm.

8. A composite valve according to claim 1, characterized in that, The nano-silicon carbide - nano-molybdenum disulfide composite material includes nano-silicon carbide, nano-molybdenum disulfide, and a silane coupling agent; the mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and the silane coupling agent is (30~50):(48~68):(1~3); the thickness of the nano-silicon carbide - nano-molybdenum disulfide composite material is 50~100 nm.

9. A composite valve according to claim 1, characterized in that, The interfacial bonding strength of the valve composite material is ≥300 Mpa, and the surface roughness Ra ≤0.8 μm.

10. A manufacturing method of a composite valve according to any one of claims 1 to 9, characterized in that, It includes the following steps: Ultrasonically clean the first alloy material, tantalum metal coated with nickel and cobalt, second alloy material, third alloy material, nano-silicon carbide - nano-molybdenum disulfide composite material, and fourth alloy material with ethanol for 0.5~1 h to remove surface oil stains. Under the condition of 800~1200 °C, use the method of vacuum diffusion welding to composite the first alloy material, tantalum metal coated with nickel and cobalt, and the second alloy material together, and keep warm and under pressure for 2~4 h to obtain the valve composite material. Mechanically process and form the valve composite material to obtain the valve body (1), valve cover (2), valve stem (3), and valve flap (4). Under the conditions of 1200~1500°C and 100~200 Mpa, the third alloy material, the nano-silicon carbide - nano-molybdenum disulfide composite material and the fourth alloy material are compounded together by hot isostatic pressing process, and heat preservation and pressure holding are carried out for 1~3 h to obtain the wear-resistant alloy; Under the conditions of argon protection, laser power of 2~5 kW and powder feeding rate of 5~20 g / min, the wear-resistant alloy is cladded on the outermost surfaces of the valve stem (3) and the valve disc (4) by laser cladding process; The obtained components are polished and assembled to obtain the composite valve.

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