Composite valve and manufacturing method thereof

Abstract

The present application discloses a composite valve and its manufacturing method, belonging to the field of valve technology. A first alloy material, a tantalum metal coated with nickel and cobalt, and a second alloy material are composited by vacuum diffusion welding, and a valve body, a valve cover, a valve stem, and a valve disc are obtained after processing; a third alloy material, a fourth alloy material, and a nano-silicon carbide-nano-molybdenum disulfide composite material are then composited by hot isostatic pressing to obtain a wear-resistant alloy; the wear-resistant alloy is further clad on the surface of the valve stem and valve disc by laser cladding; and finally, the various components are processed and assembled to obtain a composite valve. The composite valve can effectively resist the erosion of corrosive media, can withstand stress under high temperature and high pressure conditions, and can also effectively resist erosion and wear of the media.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a composite valve and a manufacturing method thereof. Background Art

[0002] Valves are indispensable fluid control devices in industrial piping systems and are widely used in the petroleum, chemical, electric power, metallurgy and other industries. Traditional valves are usually made of a single metal material, such as carbon steel, stainless steel, alloy steel, etc. However, under harsh working conditions such as high temperature, high pressure, and highly corrosive media, a single metal material is often difficult to meet the use requirements of the valve. 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 existing technology, surface treatment processes such as surfacing and spraying have the problems of low bonding strength and easy peeling. Summary of the Invention

[0003] To address the shortcomings of the existing technology, this application provides a composite valve and a manufacturing method thereof. A first alloy material, a tantalum metal coated with nickel and cobalt, and a second alloy material are composited by vacuum diffusion welding to produce a valve body, a valve cover, a valve stem, and a valve disc. A third alloy material, a fourth alloy material, and a nano-silicon carbide-nano-molybdenum disulfide composite material are then composited by hot isostatic pressing to produce a wear-resistant alloy. The wear-resistant alloy is further clad on the surfaces of the valve stem and valve disc by laser cladding. Finally, the various components are processed and assembled to produce a composite valve. This composite valve can effectively resist erosion by corrosive media, withstand stress under high-temperature and high-pressure operating conditions, and effectively resist erosion and wear from the media.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] In the first aspect, the present application provides a composite valve, comprising a valve body, a valve cover arranged on the valve body, a valve stem passing through the valve cover and extending into the interior of the valve body cavity, and a valve disc, one side of which is tightly fitted with one end of the valve stem extending into the interior of the valve body cavity, and the other side of which is tightly fitted with the valve body; the materials of the valve body, valve cover, valve stem and valve disc are all valve composite materials; the valve composite materials 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 valve disc are also covered with a wear-resistant alloy; the wear-resistant alloy includes, from the inside to the outside, a third alloy material, a nano-silicon carbide-nano-molybdenum disulfide composite material, and a fourth alloy material.

[0006] In a second aspect, the present application provides a method for manufacturing a composite valve, comprising the following steps:

[0007] The first alloy material, the 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 were ultrasonically treated with ethanol for 0.5 to 1 hour to remove surface oil stains;

[0008] The first alloy material, the tantalum metal coated with nickel and cobalt, and the second alloy material are composited together using a vacuum diffusion welding method at 800-1200°C, and the composite material is obtained by heat preservation and pressure preservation for 2-4 hours.

[0009] The valve composite material is machined and formed into a valve body, a valve cover, a valve stem and a valve disc;

[0010] The third alloy material, the fourth alloy material and the nano-silicon carbide-nano-molybdenum disulfide composite material are compounded together by hot isostatic pressing under the conditions of 1200-1500°C and 100-200 MPa, and the heat and pressure are maintained for 1-3 hours to obtain a wear-resistant alloy;

[0011] Under argon protection, laser power of 2-5 kW, and powder feeding rate of 5-20 g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem and valve disc through laser cladding process.

[0012] The prepared components are ground, polished and assembled to obtain a composite valve.

[0013] Beneficial technical effects:

[0014] During the vacuum diffusion welding process, the nickel and cobalt coatings on the tantalum metal diffuse under the high temperature conditions of the vacuum diffusion welding process, forming a diffusion layer with the first and second alloy materials, enhancing interfacial bonding strength. The coated tantalum metal is protected, allowing the majority of the tantalum metal to remain in its original state without undergoing chemical reactions or other changes. This in turn inhibits intergranular corrosion caused by carbon diffusion at high temperatures, significantly improving the corrosion resistance of the valve composite material. Simultaneously, the nano-silicon carbide-nano-molybdenum disulfide composite material in the resulting wear-resistant alloy also diffuses under the high temperature and high pressure conditions of the hot isostatic pressing process, forming a diffusion layer with the first and second alloy materials, strengthening the interfacial bonding strength of the wear-resistant alloy. The wear-resistant alloy is further clad onto the outermost surfaces of the valve stem and disc, ensuring sealing performance and significantly enhancing wear resistance at the valve stem and disc, meeting the fluid sealing and control requirements of extreme environments such as those in the petrochemical, nuclear power, and deep-sea equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of a compound valve.

[0016] Figure 2It is a schematic diagram of the process flow for preparing composite valves.

[0017] Figure 3 It is a schematic diagram of the principle of forming a valve composite material.

[0018] Figure numerals: 1, valve body; 2, valve cover; 3, valve stem; 4, valve disc. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the following examples. However, this should not be construed as limiting the scope of this application to the following examples. Without departing from the above-mentioned method concepts of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0020] In this application, the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. If the terms "first" or "second" appear, they are only used for descriptive purposes and are not to be understood as indicating or implying relative importance.

[0021] In the first aspect, the present application provides a composite valve, the structure of which is as follows: Figure 1 As shown, 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 interior of the valve body 1 cavity, and a valve disc 4 whose one side is tightly fitted with one end of the valve stem 3 extending into the interior of the valve body 1 cavity and the other side is tightly fitted with the valve body 1; the materials of the valve body 1, valve cover 2, valve stem 3 and valve disc 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 disc 4 are also covered with a wear-resistant alloy; the wear-resistant alloy includes, from the inside to the outside, a third alloy material, a nano-silicon carbide-nano-molybdenum disulfide composite material, and a fourth alloy material.

[0022] In one possible implementation, in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt and tantalum is (20-30): (20-30): (40-60).

[0023] In one possible implementation, the first alloy material includes any one of 316L stainless steel, 317L stainless steel, and Inconel 625 nickel-based alloy.

[0024] In a possible implementation, the second alloy material includes any one of Q295 high-strength low-alloy steel and Q345 high-strength low-alloy steel.

[0025] In one possible implementation, the thickness ratio of the first alloy material, the nickel- and cobalt-coated tantalum metal, and the second alloy material is (30-40):(1-3):(55-70). With this thickness ratio, the resulting valve composite material exhibits improved interfacial bonding strength and corrosion resistance.

[0026] In one possible implementation, the third alloy material includes any one of Inconel 718 nickel-based alloy and ALLOY420 nickel-based alloy; and the thickness of the third alloy material is 1-3 mm.

[0027] In one possible implementation, the fourth alloy material includes any one of Stellite 6 cobalt-based alloy and Stellite 6B cobalt-based alloy; and the thickness of the fourth alloy material is 1-2 mm.

[0028] In one possible implementation, 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 the nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent is (30~50): (48~68): (1~3); the thickness of the nano-silicon carbide-nano-molybdenum disulfide composite material is 50~100nm.

[0029] In one possible implementation, the nano-silicon carbide can be replaced by nano-aluminum oxide or nano-zirconium oxide.

[0030] In a possible implementation, the valve composite material has an interface bonding strength of ≥300 MPa and a surface roughness Ra of ≤0.8 μm.

[0031] In a second aspect, the present application provides a method for manufacturing a composite valve, such as Figure 2 As shown, the following steps are included:

[0032] The first alloy material, the 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 were ultrasonically treated with ethanol for 0.5 to 1 hour to remove surface oil stains;

[0033] At 800~1200℃, the first alloy material, tantalum metal coated with nickel and cobalt, and the second alloy material are compounded together by vacuum diffusion welding and kept warm and pressurized for 2~4h to obtain the valve composite material. The principle of this process is as follows Figure 3 As shown;

[0034] The valve composite material is machined and formed into a valve body 1, a valve cover 2, a valve stem 3 and a valve disc 4;

[0035] 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 under the conditions of 1200-1500°C and 100-200 MPa, and the heat and pressure are maintained for 1-3 hours to obtain a wear-resistant alloy.

[0036] 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 clad onto the outermost surface of the valve stem 3 and the valve disc 4 by laser cladding process;

[0037] The prepared components are ground, polished and assembled to obtain a composite valve.

[0038] The following will describe in detail a composite valve and a manufacturing method thereof provided by the present application in combination with different embodiments.

[0039] Example 1:

[0040] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0041] 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 ultrasonicate for 0.5 h to remove surface oil stains;

[0042] 2. At 800°C, 316L stainless steel, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel were composited using vacuum diffusion welding and kept warm and pressurized for 2 hours to obtain a valve composite material.

[0043] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 20:20:60;

[0044] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0045] 4. At 1200°C and 100 MPa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6 cobalt-based alloy were compounded together by hot isostatic pressing and kept hot and pressurized for 1 hour to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 35:64:1.

[0046] 5. Under the conditions of argon protection, laser power of 2kW, and powder feeding rate of 5g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0047] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0048] Example 2:

[0049] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0050] 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 ultrasonicate for 0.8 h to remove surface oil stains;

[0051] 2. At 1000°C, 317L stainless steel, tantalum metal coated with nickel and cobalt, and Q345 high-strength low-alloy steel were composited using vacuum diffusion welding and kept warm and pressurized for 3 hours to obtain a valve composite material.

[0052] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 25:25:50;

[0053] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0054] 4. At 1350°C and 150 MPa, ALLOY 420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6B cobalt-based alloy were compounded together by hot isostatic pressing and kept hot and pressurized for 2 hours to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 43:55:2.

[0055] 5. Under the conditions of argon protection, laser power of 3.5kW, and powder feeding rate of 10g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0056] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0057] Example 3:

[0058] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0059] 1. Place 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 Stellite 6 cobalt-based alloy in ethanol and ultrasonicate for 1 hour to remove surface oil stains;

[0060] 2. At 1200°C, vacuum diffusion welding was used to composite Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel. The composite material was obtained by heat preservation and pressure maintenance for 4 hours.

[0061] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 30:30:40;

[0062] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0063] 4. At 1500°C and 200 MPa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material and Stellite 6 cobalt-based alloy were compounded together by hot isostatic pressing process and kept hot and pressurized for 3 hours to obtain a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide and silane coupling agent was 38:59:3.

[0064] 5. Under the conditions of argon protection, laser power of 5kW, and powder feeding rate of 20g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and the valve disc 4 by laser cladding process;

[0065] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0066] Example 4:

[0067] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0068] 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 ultrasonicate for 0.6 h to remove surface oil stains;

[0069] 2. At 900°C, 316L stainless steel, tantalum metal coated with nickel and cobalt, and Q345 high-strength low-alloy steel were composited using vacuum diffusion welding and kept warm and pressurized for 2.5 hours to obtain a valve composite material.

[0070] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 20:20:60;

[0071] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0072] 4. At 1250°C and 120 MPa, ALLOY 420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6B cobalt-based alloy were composited together by hot isostatic pressing (HIP) for 1.5 hours to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 40:58:2.

[0073] 5. Under the conditions of argon protection, laser power of 3kW, and powder feeding rate of 15g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0074] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0075] Example 5:

[0076] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0077] 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 ultrasonicate for 0.9 h to remove surface oil stains;

[0078] 2. At 1100°C, 317L stainless steel, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel were composited using vacuum diffusion welding and kept at this temperature and pressure for 3.5 hours to obtain a valve composite material.

[0079] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 28:22:50;

[0080] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0081] 4. At 1400°C and 180 MPa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6 cobalt-based alloy were compounded together by hot isostatic pressing and kept hot and pressurized for 2.5 hours to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 32:66:2.

[0082] 5. Under the conditions of argon protection, laser power of 4kW, and powder feeding rate of 18g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0083] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0084] Example 6:

[0085] like Figure 2 As shown, a method for manufacturing a composite valve includes the following steps:

[0086] 1. Place 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 in ethanol and ultrasonicate for 0.7 h to remove surface oil stains;

[0087] 2. Under the condition of 1050℃, Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q345 high-strength low-alloy steel are compounded together by vacuum diffusion welding and kept at this temperature and pressure for 3 hours to obtain a valve composite material;

[0088] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 24:26:50;

[0089] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0090] 4. At 1300°C and 160 MPa, ALLOY 420 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6B cobalt-based alloy were compounded together by hot isostatic pressing and kept hot and pressurized for 2 hours to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 49:49:2.

[0091] 5. Under the conditions of argon protection, laser power of 3.5kW, and powder feeding rate of 12g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0092] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0093] Comparative Example 1:

[0094] A method for manufacturing a composite valve comprises the following steps:

[0095] 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 ultrasonicate for 0.5 h to remove surface oil stains;

[0096] 2. At 800°C, 316L stainless steel, tantalum metal and Q295 high-strength low-alloy steel were composited using vacuum diffusion welding and kept warm and pressurized for 2 hours to obtain a valve composite material.

[0097] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0098] 4. At 1200°C and 100 MPa, Inconel 718 nickel-based alloy, nano-silicon carbide-nano-molybdenum disulfide composite material, and Stellite 6 cobalt-based alloy were compounded together by hot isostatic pressing and kept hot and pressurized for 1 hour to produce a wear-resistant alloy. The mass ratio of nano-silicon carbide, nano-molybdenum disulfide, and silane coupling agent was 35:64:1.

[0099] 5. Under the conditions of argon protection, laser power of 2kW, and powder feeding rate of 5g / min, the wear-resistant alloy is clad onto the outermost surface of the valve stem 3 and valve disc 4 through laser cladding process;

[0100] 6. Grind, polish and assemble the prepared components to obtain a composite valve.

[0101] Comparative Example 2:

[0102] A method for manufacturing a composite valve comprises the following steps:

[0103] 1. Place Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel in ethanol and ultrasonicate for 1 hour to remove surface oil stains;

[0104] 2. At 1200°C, vacuum diffusion welding was used to composite Inconel 625 nickel-based alloy, tantalum metal coated with nickel and cobalt, and Q295 high-strength low-alloy steel. The composite material was obtained by heat preservation and pressure maintenance for 4 hours.

[0105] In the above steps 1 and 2, the mass ratio of nickel, cobalt and tantalum in the tantalum metal coated with nickel and cobalt is 30:30:40;

[0106] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0107] 4. Grind, polish and assemble the prepared components to obtain a composite valve.

[0108] Comparative Example 3:

[0109] A method for manufacturing a composite valve comprises the following steps:

[0110] 1. Place Inconel 625 nickel-based alloy, tantalum metal and Q345 high-strength low-alloy steel in ethanol and ultrasonicate for 0.7h to remove surface oil stains;

[0111] 2. At 1050°C, Inconel 625 nickel-based alloy, tantalum metal, and Q345 high-strength low-alloy steel were composited using vacuum diffusion welding and kept warm and pressurized for 3 hours to obtain a valve composite material.

[0112] 3. Mechanically process the valve composite material to obtain a valve body 1, a valve cover 2, a valve stem 3, and a valve disc 4;

[0113] 4. Grind, polish and assemble the prepared components to obtain a composite valve.

[0114] Performance testing:

[0115] With reference to CJ / T 192-2017, the interface bonding strength of the prepared composite valve was measured through a bonding strength shear test using a material testing machine at a test tensile rate of 3.0 mm / min.

[0116] With reference to GB / T 24196-2009, the corrosion potential and corrosion current of the prepared composite valve were tested by an electrochemical test method to effectively evaluate the corrosion resistance of the composite valve.

[0117] With reference to GB / T 24196-2009, the volume wear rate of the valve stem and valve disc of the prepared composite valve was tested by a wear test method to effectively evaluate the wear resistance of the composite valve.

[0118] The test results are shown in Table 1 below:

[0119] Table 1 Performance test results of composite valves prepared in Examples and Comparative Examples

[0120]

[0121] As shown in Table 1, the wear resistance, interface bonding performance and corrosion resistance of Examples 1 to 6 are better than those of Comparative Examples 1 to 3.

[0122] This is because, in Examples 1-6, during the vacuum diffusion welding process, 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 and second alloy materials, thereby enhancing the interfacial bonding strength. The coated tantalum metal is thus protected, allowing the vast majority of the tantalum metal to remain in its original state without undergoing chemical reactions or other changes, thereby inhibiting intergranular corrosion caused by carbon diffusion at high temperatures and significantly improving the corrosion resistance of the valve composite material. Simultaneously, in the resulting 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, forming a diffusion layer with the first and second alloy materials, thereby 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 disc ensures the sealing performance of the valve stem and valve disc, while also significantly enhancing the wear resistance of the valve stem and valve disc.

[0123] In Comparative Example 1, however, the surface of the tantalum metal is not coated with nickel and cobalt, and therefore cannot form a diffusion layer with the first alloy material and the second alloy material, resulting in a significant reduction in the interface bonding strength; therefore, the tantalum metal will be affected by the 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 temperatures, making it more likely to cause intergranular corrosion, thereby reducing the corrosion resistance of the valve.

[0124] In Comparative Example 2, since the outermost surfaces of the valve stem and the valve disc are not further clad with the wear-resistant alloy, the wear resistance of the valve stem and the valve disc is greatly reduced.

[0125] In Comparative Example 3, the surface of the tantalum metal is not coated with nickel and cobalt, and the outermost surfaces of the valve stem and valve disc are not further coated with a wear-resistant alloy, so the performance of the valve produced is the worst.

[0126] The above results show and describe the basic principles and main features of this application as well as the advantages of this application.

[0127] Those skilled in the art should understand that the present application is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. Such changes and improvements are intended to fall within the scope of the present application. The scope of protection claimed in the present application is defined by the equivalents of the appended claims.

Claims

1. A method for manufacturing a composite valve, characterized in that: The invention comprises a valve body (1), a valve cover (2) arranged on the valve body (1), a valve stem (3) passing through the valve cover (2) and extending into the interior of the valve body (1) chamber, and a valve flap (4) with one side tightly fitting one end of the valve stem (3) extending into the interior of the valve body (1) chamber and the other side tightly fitting the valve body (1); the material of the valve body (1), the valve cover (2), the valve stem (3) and the 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 the valve flap (4) are also covered with a wear-resistant alloy; the wear-resistant alloy includes from the inside to the outside A third alloy material, a nano-silicon carbide-nano-molybdenum disulfide composite material, and a fourth alloy material; in the tantalum metal coated with nickel and cobalt, the mass ratio of nickel, cobalt, and tantalum is (20-30): (20-30): (40-60); 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 the nano-silicon carbide, nano-molybdenum disulfide, and 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; the manufacturing method of the composite valve comprises: The first alloy material, the 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 were ultrasonically treated with ethanol for 0.5 to 1 hour to remove surface oil stains; The first alloy material, the tantalum metal coated with nickel and cobalt, and the second alloy material are composited together using a vacuum diffusion welding method at 800-1200°C, and the composite material is obtained by heat preservation and pressure preservation for 2-4 hours. Mechanically processing the valve composite material to obtain a valve body (1), a valve cover (2), a valve stem (3) and a valve disc (4); 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 under the conditions of 1200-1500°C and 100-200 MPa, and the heat and pressure are maintained for 1-3 hours to obtain a 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 clad onto the outermost surface of the valve stem (3) and the valve disc (4) by laser cladding process; The prepared components are ground, polished and assembled to obtain a composite valve.

2. The method for manufacturing a composite valve according to claim 1, wherein: The first alloy material includes any one of 316L stainless steel, 317L stainless steel and Inconel 625 nickel-based alloy.

3. The method for manufacturing 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.

4. The method for manufacturing a composite valve according to claim 1, characterized in that: 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).

5. The method for manufacturing a composite valve according to claim 1, wherein: The third alloy material includes any one of Inconel 718 nickel-based alloy and ALLOY 420 nickel-based alloy; the thickness of the third alloy material is 1-3 mm.

6. The method for manufacturing a composite valve according to claim 1, characterized in that: The fourth alloy material includes any one of Stellite 6 cobalt-based alloy and Stellite 6B cobalt-based alloy; the thickness of the fourth alloy material is 1-2 mm.

7. The method for manufacturing a composite valve according to claim 1, characterized in that: The valve composite material has an interface bonding strength of ≥300 MPa and a surface roughness Ra of ≤0.8 μm.

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