Device for preparing high-temperature alloy powder through continuous atomization and powder preparation method

Abstract

The invention provides a device for preparing high-temperature alloy powder through continuous atomization and a powder preparation method. Through cooperation of the airtight vacuum smelting furnace, the feeding bin, the feeding bin gate valve, the isolation gate valve for liquid transfer, the automatic control vehicle-mounted medium-frequency heat preservation furnace and other devices, material supplementation can be continuously conducted on the side feeding medium-frequency induction tundish; and continuous and accurate feeding for the atomizer is realized through a ceramic liquid conveying pipe and a liquid guide flow nozzle which are connected with the side feeding medium-frequency induction tundish. Meanwhile, continuous atomization and automatic grading are achieved through a high-speed rotating centrifugal atomization method and an on-line grading machine, and the goals of being fine, efficient, airtight and controllable in process and integrated in device are achieved. The technology is low in operation cost, the sphericity degree of the powder is good, the oxygen content and inclusions are easy to control, and the technology is the most advantageous preparation technology for preparing the high-end high-temperature alloy spherical powder.

Description

Technical Field

[0001] The invention relates to the technical field of metal powder preparation, and in particular to a device for preparing high-temperature alloy powder by continuous atomization and a powder making method. Background Art

[0002] High-temperature alloys have good high-temperature strength and oxidation and corrosion resistance, excellent fatigue and creep resistance, fracture performance and organizational stability. They are irreplaceable key materials for modern national defense construction and national economic development. The development of high-temperature alloys is closely related to the development of aircraft engines and various industrial gas turbines. The development of high-temperature alloys is an important guarantee for the development of aircraft engines and industrial gas turbines, and the development of aircraft engines and industrial gas turbines is the driving force for the development of high-temperature alloys. The research and development of advanced high-temperature alloy materials and processes belongs to the field of high technology. The level of development of high-temperature alloys is one of the signs of a country's industrial level. It is also one of the signs of the strength of a country's national defense. Developed countries around the world attach great importance to the research, production and application of high-temperature alloys, and have invested a lot of manpower and material resources.

[0003] Powder metallurgy is the main way to prepare turbine blades, turbine disks, combustion chambers, guide chambers, etc. for advanced aircraft engines. However, with the recent rapid upgrading of aerospace equipment, its components have higher requirements for structure. Lightweight design, complex appearance and internal structure components have become the mainstream development and application trends. Traditional manufacturing has been difficult to meet the trend of complex forming. Additive manufacturing technology will become the preferred preparation method for complex structural parts. However, the high-temperature alloy powder materials required for both powder metallurgy and additive manufacturing will increase rapidly with the rapid development of the aerospace industry, but at the same time, higher requirements are placed on the cost and performance of the powder, such as the sphericity, fluidity, satellite powder, bulk density, impurities, etc. of the powder. Therefore, in order to solve the key needs of aerospace development and meet the urgent needs of high-end manufacturing, it is imperative to develop high-quality, low-cost high-temperature alloy powder preparation technology.

[0004] At present, the common preparation methods of high-temperature alloy spherical powder include inert gas atomization (argon atomization, AA), plasma rotating electrode atomization (PREP), etc. Among them, the AA method is the most important method for producing metal powder because of its low parent material requirements and high fine powder yield. However, the gas atomization method has the following problems: (1) high impurity content, transfer / residue of impurities in the raw materials, and contact and action with refractory materials such as smelting furnaces, tundishes, and ceramic guide nozzles during the melting and atomization processes, which inevitably produce non-metallic inclusions; (2) few adjustable process parameters and a narrow process window; (3) high energy consumption, mainly involving the large consumption of inert gas; (4) inert gas is easily involved in the powder to form hollow powder or holes, and air flow disturbance is easy to produce satellite powder and irregular powder. In addition, although the sphericity of the powder prepared by the PREP method is better, the purity is higher and the hollow powder is relatively less. However, the PREP method has the following problems: (1) high raw material requirements, requiring specific process rods; (2) low fine powder recovery rate, restricted by the length / height weight of the consumable rods, limited room for rod speed improvement, and coarse powder particle size; (3) wide and unstable powder particle size distribution, affected by the dynamic balance of the rotating rods, as well as the fluctuations and instability of the melt superheat and end face shape of the atomized rod end; (4) high cost, determined by customized rods and low effective powder recovery rate. The above-mentioned many problems of commonly used powder preparation methods have seriously hindered the development and application of additive manufacturing of high-temperature alloys in the fields of aerospace, defense industry, etc. at home and abroad.

[0005] In view of the above problems, the present invention proposes a device for preparing high-temperature alloy powder by continuous atomization and a powder making method. The invention cooperates with a closed vacuum melting furnace, a charging bin, a charging bin gate valve, an isolation gate valve for liquid transfer, an automatic control vehicle-mounted medium frequency insulation furnace and other devices to continuously feed the side-feeding medium frequency induction ladle, and realizes continuous and accurate feeding of the atomizer through a ceramic infusion tube and a liquid guide nozzle connected to the side-feeding medium frequency induction ladle. At the same time, the present invention adopts a high-speed rotating centrifugal atomization method and an online classifier to realize continuous atomization and automatic grading, achieving the goals of fine and efficient, closed and controllable process, and integrated device. This technology has low operating costs, good powder sphericity, and easy control of oxygen content and inclusions, making it the most advantageous preparation technology for preparing high-end high-temperature alloy spherical powders. Summary of the invention

[0006] The main purpose of the present invention is to provide a continuous atomization device for preparing high-temperature alloy powder and a powder making method, so as to solve a series of problems in the prior art such as wide particle size distribution, low fine powder yield, satellite ball, poor fluidity, high impurity content, and high cost. In order to achieve the above purpose, according to the first aspect of the present invention, a continuous atomization device for preparing high-temperature alloy powder is provided. The device mainly includes a closed vacuum melting furnace, an automatic control vehicle-mounted medium frequency insulation furnace, a side-feeding medium frequency induction tundish, a ceramic infusion tube, an induction heating sleeve, a high-frequency induction heater for the infusion tube, a liquid flow nozzle, a micro-pressure balancer, a side return air distribution duct, an atomization chamber, a high-speed rotating centrifugal atomizer, an atomizer horizontal moving drive, a sequin large particle separator, a powder collecting tank, a 1# classifier, a 2# classifier, a high-efficiency filter, and a closed-circuit return air fan. Among them, a charging bin gate valve is installed on the upper part of the closed vacuum melting furnace and is connected to the charging bin; the closed vacuum melting furnace is equipped with a medium-frequency induction melting crucible, an isolation gate valve for liquid transfer, an automatically controlled vehicle-mounted medium-frequency holding furnace and a side-feeding medium-frequency induction tundish; the side-feeding medium-frequency induction tundish is connected to the liquid guide nozzle through a ceramic infusion tube, and an induction heating sleeve and a high-frequency induction heater for the infusion tube are installed on the outside of the ceramic infusion tube; a high-speed rotating centrifugal atomizer and a side return air distribution duct are built in the atomization chamber, and the center of the high-speed rotating centrifugal atomizer and the center of the liquid guide nozzle are located on the same horizontal line; a micro-pressure balancer and an atomizer connected to the high-speed rotating centrifugal atomizer are installed outside the atomization chamber. Horizontal moving drive; the lower part of the atomization chamber is connected to the sequin large particle separator, and the lower part of the sequin large particle separator is connected to the powder collecting tank through a butterfly valve and a transition bin; the upper air outlet of the sequin large particle separator is connected to the air inlet of the 1# classifier through a pipeline, the air outlet of the 1# classifier is connected to the air inlet of the 2# classifier through a pipeline, and the lower powder outlets of the 1# classifier and the 2# classifier are connected to the lower powder collecting tank through a butterfly valve and a transition bin; the air outlet of the 2# classifier is connected to the air inlet of the high-efficiency filter through a pipeline; the air outlet of the high-efficiency filter is connected to the air inlet of the closed-circuit return fan, and the air outlet of the closed-circuit return fan is connected to the return air inlet of the lateral return air distribution duct to realize gas recycling.

[0007] Furthermore, the closed vacuum melting furnace is connected to a vacuum pump group, and the ultimate vacuum degree is: <10Pa.

[0008] Furthermore, the high-frequency induction heater for the infusion tube has a high-frequency power supply power of 40-90Kw and a power supply frequency of 200KHz-400KHz.

[0009] Furthermore, the high-speed rotating centrifugal atomizer is driven by a variable frequency motor with a rotation speed range of 0-60000r / min.

[0010] Furthermore, the atomizer horizontal movement driver drives the high-speed rotating centrifugal atomizer to move horizontally, which is convenient for maintenance and replacement of the atomizer.

[0011] Furthermore, the lateral return air distribution duct has many holes evenly and densely distributed along the circumference, and the hole diameter is 0.5-5mm, so as to promote the generation of a uniform and stable return air field and control the cooling speed of the atomized droplets.

[0012] Furthermore, the micro-pressure balancer can stabilize the pressure in the atomization chamber to maintain a micro-positive pressure within the range of 0.3KPa±0.05KPa.

[0013] Furthermore, the outer wall of the atomizing chamber adopts a water-cooling jacket design, and the temperature of the cold water introduced is 20±5°C.

[0014] In order to achieve the above object, according to a second aspect of the present invention, a method for preparing high temperature alloy powder using the above device is provided.

[0015] The atomization method of the high temperature alloy powder adopts the above-mentioned device and specifically comprises the following steps: (1) Add the high-temperature alloy rod into the medium-frequency induction melting crucible, close the upper cover of the closed vacuum melting furnace to seal it, and start the vacuum pump group to evacuate the chamber until the vacuum degree of the melting chamber reaches below 30Pa. Then fill the melting chamber with high-purity argon gas to a slight positive pressure of 0.3Kpa±0.05Kpa. Start the heating power of the closed vacuum melting furnace, the automatic control vehicle-mounted medium-frequency holding furnace, the side-feeding medium-frequency induction tundish, and the high-frequency induction heater of the infusion tube in sequence, and control each heating unit through PLC to automatically adjust the power at different time points according to the heating process to achieve precise control of the heating temperature. (2) Adjust the atmosphere of the atomization chamber: After the atomization chamber is evacuated, high-purity argon gas is filled in, and the atomization environment pressure is ensured to be within the range of 0.3Kpa±0.05Kpa through a micro-pressure balancer, and the oxygen content in the atomization chamber is achieved to be 10-50ppm. (3) After the high-temperature alloy rod in the medium-frequency induction melting crucible is melted, the isolation gate valve for liquid transfer is opened, the automatic-controlled vehicle-mounted medium-frequency holding furnace is moved to the side of the medium-frequency induction melting crucible, and the high-temperature alloy melt in the medium-frequency induction melting crucible is poured into the automatic-controlled vehicle-mounted medium-frequency holding furnace; after the melt is transferred to the automatic-controlled vehicle-mounted medium-frequency holding furnace, the automatic-controlled vehicle-mounted medium-frequency holding furnace is moved to the side of the side-fed medium-frequency induction tundish, the isolation gate valve for liquid transfer is closed, and the melt is poured into the side-fed medium-frequency induction tundish; the melt poured into the side-fed medium-frequency induction tundish is continuously fed to the high-speed rotating centrifugal atomizer through the connected infusion tube and liquid guide nozzle. (4) After the high-temperature alloy melt is poured into the medium-frequency induction melting crucible, the medium-frequency induction melting crucible is charged with materials under the protection of a closed inert atmosphere by cooperating with the opening of the charging bin plug valve and the charging bin on the upper part of the closed vacuum melting furnace. (5) After the atomization equipment is started, the speed of the high-speed rotating centrifugal atomizer is set to 6000r / min. When the high-temperature alloy melt flows out through the liquid guide nozzle, the speed is adjusted to 12000r / min. After the temperature of the high-speed rotating centrifugal atomizer stabilizes, the speed is adjusted to 48000-60000r / min to enter a continuous and stable atomization state. (6) After atomization, the powder first passes through the large particle separator at the bottom of the atomization chamber to remove the large particles and the sequins. Then, the powder passes through the No. 1 classifier and the No. 2 classifier to classify the powder online according to the required particle size. The removed large particles and the classified powder are loaded into the powder collecting tank through the butterfly valve and the transition bin. (7) After passing through the classifier, the argon gas passes through a high-efficiency filter to remove the ultrafine powder carried by the airflow. Finally, it passes through the return air fan to send the filtered and purified argon gas to the side return air distribution duct to achieve the recycling of the argon gas.

[0016] Furthermore, the heating units of the closed vacuum melting furnace, the automatically controlled vehicle-mounted medium frequency holding furnace, the side-feeding medium frequency induction tundish, and the infusion pipe high frequency induction heater described in step (1) are controlled to have a heating temperature within the range of 1550-1750°C during operation.

[0017] Furthermore, the diameter of the liquid guide nozzle in step (3) is in the range of 3-5 mm, and the flow rate range for continuously feeding the high-speed rotating centrifugal atomizer is 5-12 kg / min.

[0018] Furthermore, in step (4), the rod material is added to the medium frequency induction melting crucible by first closing the charging bin gate valve, opening the charging bin door, adding the rod material, and closing the charging bin door. After closing the bin door, the charging bin is evacuated by the vacuum pump group to a vacuum degree of <10Pa, and then high-purity argon gas is filled into the bin body to normal pressure (gauge pressure is 0). After filling, the charging bin gate valve is opened to complete the addition of the material to the medium frequency induction melting crucible, and finally the charging bin gate valve is closed to enter the next feeding cycle.

[0019] Furthermore, the rotation speed range of the 1# classifier and the 2# classifier in step (6) is adjustable from 0 to 3600 r / min, which can be adjusted according to the required particle size distribution and can be coordinated with the overall air volume to achieve online precise classification. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 This is a diagram of a device for preparing high-temperature alloy powder by continuous atomization in the present invention; Figure 2 A partial diagram of a device for preparing high-temperature alloy powder by continuous atomization in the present invention; Figure 3 SEM photo of GH4169 powder. In the figure: 1. Closed vacuum melting furnace; 2. Automatically controlled vehicle-mounted medium frequency holding furnace; 3. Side-feed medium frequency induction tundish; 4. Ceramic infusion pipe; 5. Induction heating sleeve; 6. High-frequency induction heater for infusion pipe; 7. Liquid guide nozzle; 8. Micro-pressure balancer; 9. Side return air distribution duct; 10. Atomization chamber; 11. High-speed rotating centrifugal atomizer; 12. Atomizer horizontal movement drive; 13. Sequin large particle selector; 14. Powder collecting tank; 15. 1# classifier; 16. 2# classifier; 17. High-efficiency filter; 18. Closed-circuit return air fan; 1-1. Feeding bin; 1-2. Feeding bin plug valve; 1-3. Medium frequency induction melting crucible; 1-4. Isolation plug valve for liquid transfer. DETAILED DESCRIPTION

[0021] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0022] The present invention discloses a device for preparing high temperature alloy powder by continuous atomization. Figure 1-2As shown, the device mainly includes a closed vacuum melting furnace 1, an automatically controlled vehicle-mounted medium frequency holding furnace 2, a side-feeding medium frequency induction tundish 3, a ceramic infusion pipe 4, an induction heating sleeve 5, a high-frequency induction heater for the infusion pipe 6, a liquid guide nozzle 7, a micro-pressure balancer 8, a side return air distribution duct 9, an atomization chamber 10, a high-speed rotating centrifugal atomizer 11, an atomizer horizontal moving driver 12, a sequin large particle selector 13, a powder collecting tank 14, a No. 1 classifier 15, a No. 2 classifier 16, a high-efficiency filter 17, and a closed-circuit return air fan 18. Among them, a charging bin gate valve 1-2 is installed on the upper part of the closed vacuum melting furnace 1 and is connected to the charging bin 1-1; a medium-frequency induction melting crucible 1-3, an isolation gate valve 1-4 for liquid transfer, an automatically controlled vehicle-mounted medium-frequency insulation furnace 2 and a side-feeding medium-frequency induction tundish 3 are installed in the closed vacuum melting furnace 1; the side-feeding medium-frequency induction tundish 3 is connected to the liquid guide nozzle 7 through a ceramic infusion tube 4, and an induction heating sleeve 5 and an infusion tube high-frequency induction heater 6 are installed on the outside of the ceramic infusion tube 4; a high-speed rotating centrifugal atomizer 11 and a side return air distribution duct 9 are installed in the atomization chamber 10, and the center of the high-speed rotating centrifugal atomizer 11 and the center of the liquid guide nozzle 7 are located on the same horizontal line; a micro-pressure balancer 8 and an atomizer water connected to the high-speed rotating centrifugal atomizer 11 are installed outside the atomization chamber 10. The horizontal moving drive 12; the lower part of the atomizing chamber 10 is connected to the large sequin particle separator 13, and the lower part of the large sequin particle separator 13 is connected to the powder collecting tank 14 through a butterfly valve and a transition bin; the upper air outlet of the large sequin particle separator 13 is connected to the air inlet of the 1# classifier 15 through a pipeline, and the air outlet of the 1# classifier 15 is connected to the air inlet of the 2# classifier 16 through a pipeline, and the lower powder outlets of the 1# classifier 15 and the 2# classifier 16 are connected to the lower powder collecting tank 14 through a butterfly valve and a transition bin; the air outlet of the 2# classifier 16 is connected to the air inlet of the high-efficiency filter 17 through a pipeline; the air outlet of the high-efficiency filter 17 is connected to the air inlet of the closed-circuit return air fan 18, and the air outlet of the closed-circuit return air fan 18 is connected to the return air inlet of the lateral return air distribution duct 9 to realize gas recycling.

[0023] Optionally, the closed vacuum melting furnace 1 is connected to a vacuum pump group, and the ultimate vacuum degree is: <10Pa.

[0024] Optionally, the infusion tube high-frequency induction heater 6 has a high-frequency power supply power of 40-90Kw and a frequency of 200KHz-400KHz.

[0025] Optionally, the high-speed rotating centrifugal atomizer 11 is driven by a variable frequency motor with a rotation speed range of 0-60000r / min.

[0026] Optionally, the atomizer horizontal movement driver 12 drives the high-speed rotating centrifugal atomizer 11 to move horizontally, which facilitates maintenance and replacement of the atomizer.

[0027] Optionally, the lateral return air distribution duct 9 has many holes evenly and densely distributed along the circumference, and the hole diameter is 0.5-5mm, so as to promote the generation of a uniform and stable return air field and control the cooling speed of the atomized droplets.

[0028] Optionally, the micro-pressure balancer 8 can stabilize the pressure in the atomization chamber 10 to maintain a micro-positive pressure within the range of 0.3KPa±0.05KPa.

[0029] Optionally, the outer wall of the atomization chamber 10 is designed with a water-cooling jacket, and the temperature of the cold water introduced is 20±5°C.

[0030] Correspondingly, the present invention discloses a method for preparing high-temperature alloy powder using the above-mentioned device. The atomization method of the high temperature alloy powder specifically comprises the following steps: (1) Add high-temperature alloy rods into the medium frequency induction melting crucible 1-3, close the upper cover of the closed vacuum melting furnace 1 to seal it, and start the vacuum pump group to evacuate the chamber until the vacuum degree of the melting chamber reaches below 30Pa. Then, high-purity argon gas can be filled into the melting chamber to a slight positive pressure of 0.3Kpa±0.05Kpa. The heating power supplies of the closed vacuum melting furnace 1, the automatic control vehicle-mounted medium frequency holding furnace 2, the side-feeding medium frequency induction tundish 3, and the infusion tube high-frequency induction heater 6 are correctly turned on in sequence, and the PLC controls each heating unit to automatically adjust the power at different time points according to the heating process to achieve precise control of the heating temperature. (2) Adjusting the atmosphere of the atomization chamber: After the atomization chamber 10 is evacuated, high-purity argon gas is filled in, and the atomization environment pressure is ensured to be within the range of 0.3KPa±0.05KPa through the micro-pressure balancer 8, and the oxygen content in the atomization chamber is achieved to be 10-50ppm. (3) After the high-temperature alloy rod in the medium-frequency induction melting crucible 1-3 is melted, the isolating gate valve 1-4 for liquid transfer is opened, the automatic-controlled vehicle-mounted medium-frequency insulation furnace 2 is moved to the side of the medium-frequency induction melting crucible 1-3, and the high-temperature alloy melt in the medium-frequency induction melting crucible 1-3 is poured into the automatic-controlled vehicle-mounted medium-frequency insulation furnace 2; after the melt is transferred to the automatic-controlled vehicle-mounted medium-frequency insulation furnace 2, the automatic-controlled vehicle-mounted medium-frequency insulation furnace 2 is moved to the side of the side-feeding medium-frequency induction ladle 3, the isolating gate valve 1-4 for liquid transfer is closed, and the melt is poured into the side-feeding medium-frequency induction ladle 3; the melt poured into the side-feeding medium-frequency induction ladle 3 is continuously fed to the high-speed rotating centrifugal atomizer 11 through the connected liquid infusion tube 4 and liquid guide nozzle 7. (4) After the high temperature alloy melt is poured into the medium frequency induction melting crucible 1-3, the charging bin gate valve 1-2 on the upper part of the closed vacuum melting furnace 1 and the charging bin 1-1 are opened and coordinated to realize the charging of the medium frequency induction melting crucible 1-3 under the protection of a closed inert atmosphere. (5) After the atomization equipment is started, the speed of the high-speed rotating centrifugal atomizer 11 is set to 6000 r / min. When the high-temperature alloy melt flows out through the liquid guide nozzle 7, the speed is adjusted to 12000 r / min. After the temperature of the high-speed rotating centrifugal atomizer is stabilized, the speed is adjusted to 48000-60000 r / min to enter a continuous stable atomization state. (6) After atomization, the powder first passes through the large sequin particle remover 13 at the bottom of the atomization chamber 10 to remove the sequins and large particles, and then passes through the 1# classifier 15 and the 2# classifier 16 to classify the powder online according to the required particle size. The removed large sequin particles and the classified powder are loaded into the powder collecting tank 14 through the butterfly valve and the transition bin. (7) After passing through the classifier, the argon gas passes through the high-efficiency filter 17 to filter out the ultrafine powder carried by the airflow, and finally passes through the return air fan 18 to send the filtered and purified argon gas to the side return air distribution duct 9 to realize the recycling of the argon gas.

[0031] Optionally, the heating units of the closed vacuum melting furnace 1, the automatically controlled vehicle-mounted medium frequency holding furnace 2, the side-feeding medium frequency induction tundish 3, and the infusion pipe high frequency induction heater 6 described in step (1) are controlled to have a heating temperature within the range of 1550-1750°C during operation.

[0032] Optionally, the diameter of the liquid guide nozzle 7 in step (3) is in the range of 3-5 mm, and the flow rate range for continuously feeding the high-speed rotating centrifugal atomizer 11 is 5-12 kg / min.

[0033] Optionally, in step (4), the rod material is added to the medium frequency induction melting crucible 1-3 by first closing the charging bin gate valve 1-2, opening the charging bin door 1-1, adding the rod material, and closing the charging bin door 1-1. After closing the bin door, the charging bin 1-1 is evacuated to a vacuum degree of <10Pa by a vacuum pump group, and then high-purity argon gas is filled into the bin body to normal pressure (gauge pressure is 0). After filling, the charging bin gate valve 1-2 is opened to complete the addition of material to the medium frequency induction melting crucible 1-3, and finally the charging bin gate valve 1-2 is closed to enter the next feeding cycle.

[0034] Optionally, the rotation speed range of the 1# classifier 15 and the 2# classifier 16 in step (6) is adjustable from 0 to 3600 r / min, which can be adjusted according to the required particle size distribution and coordinated with the overall air volume to achieve online precise classification.

[0035] The present invention will be described in further detail below through specific examples. Embodiment 1: 200 kg of GH4169 high-temperature alloy rods are selected and added into the medium-frequency induction melting crucible 1-3, the upper cover of the closed vacuum melting furnace 1 is closed for sealing, and the vacuum pump group is turned on for vacuuming until the vacuum degree of the melting chamber reaches 25 Pa. High-purity argon gas can be filled into the melting chamber to a slight positive pressure of 0.3 Kpa ± 0.05 Kpa, and the heating power supplies of the closed vacuum melting furnace 1, the automatic control vehicle-mounted medium-frequency holding furnace 2, the side-feeding medium-frequency induction ladle 3, and the infusion tube high-frequency induction heater 6 are turned on in sequence. Among them, the infusion tube high-frequency induction heater uses a 60Kw high-frequency power supply with a frequency of 400KHz, and the temperature of each heating unit is achieved at 1640±10°C through PLC control. After the atomizing chamber 10 is evacuated and filled with high-purity argon gas, the atomizing environment pressure is ensured to be within the range of 0.3Kpa±0.05Kpa through the micro-pressure balancer 8, and the oxygen content in the atomizing chamber is 10-50ppm, so as to complete the preparation of the atomizing chamber atmosphere. After the bar material in the medium frequency induction melting crucible 1-3 is melted, the isolation gate valve 1-4 for liquid transfer is opened, the automatic control vehicle-mounted medium frequency holding furnace 2 is moved to the side of the medium frequency induction melting crucible 1-3, and the GH4169 alloy melt in the medium frequency induction melting crucible 1-3 is poured into the automatic control vehicle-mounted medium frequency holding furnace 2. After the melt is transferred to the automatically controlled vehicle-mounted medium frequency insulation furnace 2, the automatically controlled vehicle-mounted medium frequency insulation furnace 2 is moved to the side of the side-fed medium frequency induction ladle 3, the isolation gate valve 1-4 for liquid transfer is closed, and the melt is poured into the side-fed medium frequency induction ladle 3. The melt poured into the side-fed medium frequency induction ladle 3 is continuously fed to the high-speed rotating centrifugal atomizer 11 through the connected infusion pipe 4 and the liquid guide nozzle 7. The diameter range of the liquid guide nozzle 7 is 3-5mm, and the melt flow rate is controlled to be 5.5 kg / min. After the melt is transferred to the automatic control vehicle-mounted medium frequency holding furnace 2, the atomization equipment is started, and the speed of the high-speed rotating centrifugal atomizer 11 is set to 6000r / min. When the melt flows out through the liquid guide nozzle 7, the speed is adjusted to 12000r / min. After the temperature of the high-speed rotating centrifugal atomizer is stable (about 2min), the speed is adjusted to 48000r / min, and the continuous stable atomization state is entered. After atomization, the powder first passes through the sequin large particle selector 13 to remove the sequins and large particles and then passes through the 2-stage classifier. The speeds of the 1# classifier 15 and the 2# classifier 16 are set to 1200r / min and 2280r / min respectively, so that the powder can be classified online to obtain 15-53μm. The argon gas after the classifier is then passed through the high-efficiency filter 17 to filter out the ultrafine powder carried by the airflow, and finally the filtered and purified argon gas is sent to the side return air distribution duct 9 through the return air fan 18 and the argon gas is recycled through the circumferentially evenly distributed 4mm apertures, and the cooling rate of the atomized droplets is controlled. At the same time, in order to ensure the online addition of rods to the medium frequency induction melting crucible 1-3, first close the charging bin gate valve 1-2, open the charging bin 1-1 door, add the rods, and close the charging bin 1-1 door. After closing the bin door, use the vacuum pump group to evacuate the charging bin 1-1 to a vacuum degree of <10Pa, and then fill the bin body with high-purity argon gas to normal pressure (gauge pressure is 0). After inflation, open the charging bin gate valve 1-2 to complete the addition to the medium frequency induction melting crucible 1-3, and realize online feeding under the protection of a closed inert atmosphere. The morphology of the 15-53μm product obtained above is as follows after testing and analysis. Figure 3 As shown, oxygen content is 150PPm, fluidity is 15s / 50g, and bulk density is 4.56 g / cm 3 . The metal powder prepared by the preparation method in Example 1 of the present invention is a high-grade spherical powder, which has the advantages of high sphericity, narrow particle size distribution, low oxygen content and inclusions, and low cost, and is suitable for application and promotion. In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. The technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A device for preparing high-temperature alloy powder by continuous atomization, characterized in that: The device mainly includes a closed vacuum melting furnace, an automatically controlled vehicle-mounted medium frequency holding furnace, a side-feeding medium frequency induction tundish, a ceramic infusion pipe, an induction heating sleeve, a high-frequency induction heater for the infusion pipe, a liquid guide nozzle, a micro-pressure balancer, a side return air distribution duct, an atomization chamber, a high-speed rotating centrifugal atomizer, an atomizer horizontal movement drive, a sequin large particle selector, a powder collecting tank, a No. 1 classifier, a No. 2 classifier, a high-efficiency filter, and a closed-circuit return air fan.

2. The device according to claim 1, characterized in that The device is assembled in the following manner: a charging bin gate valve is installed on the upper part of the closed vacuum melting furnace and is connected to the charging bin; a medium-frequency induction melting crucible, an isolation gate valve for liquid transfer, an automatically controlled vehicle-mounted medium-frequency insulation furnace and a side-feeding medium-frequency induction tundish are installed in the closed vacuum melting furnace; the side-feeding medium-frequency induction tundish is connected to the liquid guide nozzle through a ceramic infusion tube, and an induction heating sleeve and a high-frequency induction heater for the infusion tube are installed on the outside of the ceramic infusion tube; a high-speed rotating centrifugal atomizer and a side return air distribution duct are installed in the atomization chamber, and the center of the high-speed rotating centrifugal atomizer and the center of the liquid guide nozzle are located on the same horizontal line; a micro-pressure balancer and a Atomizer horizontal movement driver; the lower part of the atomization chamber is connected to the sequin large particle separator, and the lower part of the sequin large particle separator is connected to the powder collecting tank through a butterfly valve and a transition bin; the upper outlet of the sequin large particle separator is connected to the air inlet of the 1# classifier through a pipeline, the air outlet of the 1# classifier is connected to the air inlet of the 2# classifier through a pipeline, and the lower powder outlets of the 1# classifier and the 2# classifier are connected to the lower powder collecting tank through a butterfly valve and a transition bin; the air outlet of the 2# classifier is connected to the air inlet of the high-efficiency filter through a pipeline; the air outlet of the high-efficiency filter is connected to the air inlet of the closed-circuit return fan, and the air outlet of the closed-circuit return fan is connected to the return air inlet of the lateral return air distribution duct to realize gas recycling.

3. The device according to claim 1, characterized in that The closed vacuum melting furnace is connected to a vacuum pump group, and the ultimate vacuum degree is: <10Pa.

4. The device according to claim 1, characterized in that The high-frequency induction heater for the infusion tube has a high-frequency power supply power of 40-90Kw and a frequency of 200KHz-400KHz.

5. The device according to claim 1, characterized in that The high-speed rotating centrifugal atomizer is driven by a variable frequency motor with a rotation speed range of 0-60000r / min.

6. The device according to claim 1, characterized in that The atomizer horizontal movement driver drives the high-speed rotating centrifugal atomizer to move horizontally, which is convenient for maintenance and replacement of the atomizer.

7. The device according to claim 1, characterized in that The lateral return air distribution duct has many holes evenly and densely distributed along the circumference, and the hole diameter is 0.5-5mm, so as to promote the generation of a uniform and stable return air field and control the cooling speed of the atomized droplets.

8. The device according to claim 1, characterized in that The micro-pressure balancer can stabilize the pressure in the atomization chamber within the range of 0.3KPa±0.05KPa and maintain a micro-positive pressure.

9. The device according to claim 1, characterized in that The outer wall of the atomizing chamber adopts a water-cooling jacket design, and the temperature of the cold water introduced is 20±5°C.

10. A method for atomizing high temperature alloy powder, characterized in that: The atomization method of the high temperature alloy powder adopts the above-mentioned device, and the method comprises the following steps: (1) Add the high-temperature alloy rod into the medium-frequency induction melting crucible, close the upper cover of the closed vacuum melting furnace to seal it, and start the vacuum pump group to evacuate the chamber until the vacuum degree of the melting chamber reaches below 30Pa. Then fill the melting chamber with high-purity argon gas to a slight positive pressure of 0.3Kpa±0.05Kpa. Start the heating power of the closed vacuum melting furnace, the automatic control vehicle-mounted medium-frequency holding furnace, the side-feeding medium-frequency induction tundish, and the high-frequency induction heater of the infusion tube in sequence, and control each heating unit through PLC to automatically adjust the power at different time points according to the heating process to achieve precise control of the heating temperature. (2) Adjust the atmosphere of the atomization chamber: After the atomization chamber is evacuated, high-purity argon gas is filled in, and the atomization environment pressure is ensured to be within the range of 0.3Kpa±0.05Kpa through a micro-pressure balancer, and the oxygen content in the atomization chamber is achieved to be 10-50ppm. (3) After the high-temperature alloy rod in the medium-frequency induction melting crucible is melted, the isolation gate valve for liquid transfer is opened, the automatic-controlled vehicle-mounted medium-frequency holding furnace is moved to the side of the medium-frequency induction melting crucible, and the high-temperature alloy melt in the medium-frequency induction melting crucible is poured into the automatic-controlled vehicle-mounted medium-frequency holding furnace; after the melt is transferred to the automatic-controlled vehicle-mounted medium-frequency holding furnace, the automatic-controlled vehicle-mounted medium-frequency holding furnace is moved to the side of the side-fed medium-frequency induction tundish, the isolation gate valve for liquid transfer is closed, and the melt is poured into the side-fed medium-frequency induction tundish; the melt poured into the side-fed medium-frequency induction tundish is continuously fed to the high-speed rotating centrifugal atomizer through the connected infusion tube and liquid guide nozzle. (4) After the high-temperature alloy melt is poured into the medium-frequency induction melting crucible, the medium-frequency induction melting crucible is charged with materials under the protection of a closed inert atmosphere by cooperating with the opening of the charging bin plug valve and the charging bin on the upper part of the closed vacuum melting furnace. (5) After the atomization equipment is started, the speed of the high-speed rotating centrifugal atomizer is set to 6000r / min. When the high-temperature alloy melt flows out through the liquid guide nozzle, the speed is adjusted to 12000r / min. After the temperature of the high-speed rotating centrifugal atomizer stabilizes, the speed is adjusted to 48000-60000r / min to enter a continuous and stable atomization state. (6) After atomization, the powder first passes through the large particle separator at the bottom of the atomization chamber to remove the large particles and the sequins. Then, the powder passes through the No. 1 classifier and the No. 2 classifier to classify the powder online according to the required particle size. The removed large particles and the classified powder are loaded into the powder collecting tank through the butterfly valve and the transition bin. (7) After passing through the classifier, the argon gas passes through a high-efficiency filter to remove the ultrafine powder carried by the airflow. Finally, it passes through the return air fan to send the filtered and purified argon gas to the side return air distribution duct to achieve the recycling of the argon gas.

11. According to the step (1) of claim 10, the heating units of the closed vacuum melting furnace, the automatically controlled vehicle-mounted medium frequency holding furnace, the side-feeding medium frequency induction tundish, and the infusion pipe high frequency induction heater, the heating temperature is controlled within the range of 1550-1750°C during operation.

12. According to the step (3) of claim 10, the diameter of the liquid guide nozzle is in the range of 3-5 mm, and the continuous feed flow rate to the high-speed rotating centrifugal atomizer is in the range of 5-12 kg / min.

13. According to the step (4) of claim 10, in the step of adding rod material into the medium frequency induction melting crucible, firstly close the charging bin gate valve, open the charging bin door, add the rod material, and close the charging bin door. After closing the bin door, evacuate the charging bin by a vacuum pump group to a vacuum degree of <10Pa, and then fill the bin body with high-purity argon gas to normal pressure (gauge pressure is 0). After filling, open the charging bin gate valve to complete the feeding of the medium frequency induction melting crucible, and finally close the charging bin gate valve to enter the next feeding cycle.

14. In step (6) according to claim 10, the rotation speed range of the 1# classifier and the 2# classifier is adjustable from 0 to 3600 r / min, which can be adjusted according to the required particle size distribution, and coordinated with the overall air volume to achieve online precise classification.

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