A method and device for vacuum induction melting and casting forming of a copper-chromium-zirconium alloy

Abstract

The present invention discloses a method and device for vacuum induction melting and casting of copper-chromium-zirconium alloy, belonging to the field of alloy casting. The method is as follows: Put metallic chromium and electrolytic copper into the crucible, evacuate the air and isolate the melting furnace from the pouring chamber, heat until the metals in the crucible melt, introduce inert gas into the melting furnace, let the metallic zirconium in the melting furnace fall into the crucible and keep warm, restore the connection between the melting furnace and the pouring chamber, and the molten metal leaks into the mold. When melting metallic chromium and electrolytic copper, the vacuum environment inhibits oxidation reaction and nitridation reaction. Introducing inert gas and delaying the addition of metallic zirconium can avoid the burning loss and volatilization of metallic zirconium. There is a pressure difference between the restored-connected pouring chamber and melting furnace, enabling the molten metal to quickly leak into the mold under the action of gravity and pressure difference. During the whole process, the materials do not communicate with the outside world, which can greatly reduce the surface oxidation of the casting. The slag floating on the surface of the molten metal will not enter the mold, greatly improving the quality of the casting. There is no need for a pouring device, saving factory space.

Description

Technical Field

[0001] The present invention relates to a method and device for vacuum induction melting and casting of copper-chromium-zirconium alloy, belonging to the field of alloy casting. Background Art

[0002] In the prior art, when casting copper-chromium-zirconium alloy, a vacuum melting and casting process is usually adopted. Under vacuum conditions, metal raw materials such as copper, chromium, and zirconium are melted, which can reduce the oxidation of alloying elements and precisely control the alloy composition. Then, the melted metal liquid is poured into a specific mold and naturally cooled and solidified under the action of gravity. The vacuum melting and casting process is suitable for manufacturing large-sized and complex-shaped copper-chromium-zirconium alloy castings, such as conductive components in some large electrical equipment.

[0003] When casting copper-chromium-zirconium alloy with the current vacuum melting and casting process, there are still some disadvantages. The vacuum melting and casting process is suitable for manufacturing large castings weighing from several hundred kilograms to several tons. Therefore, the volume of the metal liquid is also very large. Pouring the metal liquid into the mold means that the mechanical components related to the pouring operation also have a relatively large volume, and enough space must be reserved to avoid the overturned crucible, resulting in the melting and casting device consuming a lot of factory space and having too large a floor area. Moreover, although melting the metal under vacuum conditions can reduce the oxidation of alloying elements, there is still a relatively long time for the metal liquid to contact the outside air during pouring. The actually obtained casting has a relatively thick oxide layer. At the same time, some slag is easily involved in the metal ingot during pouring. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a method and device for vacuum induction melting and casting of copper-chromium-zirconium alloy, which can reduce the oxidation of copper-chromium-zirconium alloy and save factory space.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0006] In the first aspect, the present application provides a method for vacuum induction melting and casting of copper-chromium-zirconium alloy, including the following steps:

[0007] Put metal chromium and electrolytic copper into the crucible in the melting furnace, and place metal zirconium in the melting furnace outside the crucible;

[0008] Preheat the mold in the pouring chamber located below the melting furnace and communicating with the melting furnace, and evacuate the melting furnace;

[0009] Use a movable liquid leakage mechanism to isolate the melting furnace from the pouring chamber, inductively heat until the metal in the crucible is completely melted, introduce an inert gas into the melting furnace to normal pressure; let the metal zirconium fall into the crucible, and inductively keep warm;

[0010] Use the movable liquid leakage mechanism to restore the connection between the smelting furnace and the pouring chamber, so that the molten metal in the crucible leaks into the mold;

[0011] Terminate the inductive heat preservation, introduce air into the smelting furnace to make the pouring chamber reach normal pressure, remove the mold from the pouring chamber, and obtain a formed copper-chromium-zirconium alloy in the mold.

[0012] In the vacuum induction melting and casting forming method of copper-chromium-zirconium alloy provided by this application, when melting metallic chromium and electrolytic copper, a vacuum environment is created to inhibit oxidation reaction and nitridation reaction, and remove volatile impurities. The addition of metallic zirconium is delayed, and before adding metallic zirconium, an inert gas that is difficult to dissolve is introduced to restore normal pressure, which can avoid the burning loss of metallic zirconium and inhibit the volatilization of metallic zirconium. The inert gas filled just forms a pressure difference with the negative-pressure pouring chamber during the liquid leakage stage, so that the chromium-containing copper liquid with poor fluidity can quickly fall and leak under the action of gravity and pressure difference, filling the mold. Throughout the process, the materials are in a vacuum environment or an inert atmosphere, which can greatly reduce the surface oxidation of the finished product. Moreover, since the molten metal in the present invention leaks into the mold from the bottom of the crucible, a small amount of slag formed floats on the surface of the molten metal and will not enter the mold, greatly improving the quality of the casting. Further, the present invention does not require a pouring device, which can save factory space.

[0013] Further, the preset power of the inductive heating is 120 kW to 150 kW; during the process of the inductive heating from starting to reaching the preset power, the power increase amplitude is 10 kW / min.

[0014] Adopting these inductive heating parameters can ensure that copper and chromium are fully melted and fully mixed under the action of electromagnetic stirring. Gradually increasing the inductive heating power to the preset power can avoid metal vaporization and is beneficial to extending the equipment life.

[0015] Further, before restoring the connection between the smelting furnace and the pouring chamber, the power of the inductive heat preservation is 120 kW to 130 kW, and the time is 20 min to 30 min.

[0016] Adopting these heat preservation parameters can ensure that the later-added zirconium can also be fully melted and evenly mixed with the copper liquid, and can avoid the burning loss and volatilization of zirconium.

[0017] In the second aspect, the present application provides an apparatus for the vacuum induction melting and casting method of copper-chromium-zirconium alloy as described in the first aspect, comprising a pouring chamber, a smelting furnace with a furnace cover and a crucible arranged in the smelting furnace, wherein the pouring chamber is connected to the bottom of the smelting furnace, a liquid leakage port is provided at the bottom of the crucible and is connected to a movable liquid leakage mechanism, wherein the movable liquid leakage mechanism is provided with two guide holes superimposed one on the other, wherein the two guide holes connect the crucible and the pouring chamber when they are aligned, and isolate the smelting furnace and the pouring chamber when the two guide holes are staggered, and the furnace cover is provided with a gas guide port and a funnel buffer chamber for feeding materials into the crucible.

[0018] The device provided in the present application can meet the requirements of the method described in the first aspect. The air guide port on the furnace cover is used for vacuuming and introducing gas. By utilizing the funnel buffer chamber, the addition of metal zirconium can be delayed without opening the furnace cover when adding metal zirconium to the molten metal. The movable liquid leakage mechanism aligns the two guide holes during vacuuming to allow the smelting furnace and the pouring chamber to be vacuumed simultaneously through the air guide port on the furnace cover. The two guide holes are staggered before the metal is melted by inductive heating to prevent copper and chromium from falling directly into the mold after melting. The two guide holes are aligned only after the zirconium is melted and mixed to allow the molten metal to leak into the mold.

[0019] Furthermore, a partition is provided between the smelting furnace and the pouring chamber to separate the two, the movable liquid leakage mechanism includes a guide tube passing through the partition, the guide hole includes an upper guide hole fixed relatively to the crucible and a lower guide hole fixed relatively to the guide tube, the part of the guide tube in the pouring chamber is transmission-connected to a driving mechanism for driving the guide tube to rotate around the axis of the guide tube, and the axis of the guide tube does not coincide with the guide hole.

[0020] The smelting furnace and pouring chamber arranged up and down can switch between an isolated state and a connected state through a combination of partitions, guide pipes and guide holes, which is equivalent to replacing a bulky dumping structure with a smaller component, thus saving factory space.

[0021] Furthermore, the movable liquid leakage mechanism also includes a fixed plug for sealing the leakage port and a rotating plug for sealing the upper end of the guide tube, the upper guide hole is penetrated by the fixed plug, the lower guide hole is penetrated by the rotating plug, the fixed plug and the rotating plug are abutted against each other up and down, the bottom of the fixed plug is provided with at least one upwardly recessed annular groove, and the top of the rotating plug is provided with a convex ring matching the annular groove.

[0022] In actual production, there is usually a need to replace the crucible, etc. A fixed plug is provided to seal the bottom of the crucible and a rotating plug is provided to seal the upper end of the guide tube. The rotational connection between the two is used to control the alignment and staggering of the guide holes, so as to facilitate the disassembly and reorganization of the equipment when replacing the crucible. The fixed plug and the rotating plug are abutted against each other up and down, and the cooperation of the annular groove and the convex ring can improve the sealing performance of the fixed plug and the rotating plug, avoid residual molten metal between the fixed plug and the rotating plug, and avoid blockage of the internal channel of the movable leakage mechanism due to solidification of the residual molten metal.

[0023] Furthermore, the inner bottom of the crucible is inclined downward from the outside to the center, the inner diameter of the liquid leakage port is gradually expanded from top to bottom, and the inner wall of the liquid leakage port has at least one turning angle formed by the expansion of the inner diameter.

[0024] The tilted design of the bottom of the crucible can ensure that the molten metal can flow smoothly to the leakage port after melting. The structure of the leakage port is conducive to sealing with the fixed plug and increasing the friction between the crucible and the fixed plug, ensuring that the fixed plug is always stationary relative to the crucible.

[0025] Furthermore, the driving mechanism includes an adjusting rod passing through the pouring chamber, the adjusting rod having an end outside the pouring chamber connected to a diversion opening and closing handle, the adjusting rod having an end inside the pouring chamber provided with a first bevel tooth, and the portion of the diversion tube in the pouring chamber provided with a second bevel tooth meshing with the first bevel tooth.

[0026] When the opening and closing handle is rotated, the adjusting rod drives the first bevel tooth to rotate, which is transmitted to the second bevel tooth to change the rotation plane. The guide tube and the rotating plug rotate synchronously with the second bevel tooth, so that the worker can control the alignment or stagger of the guide holes through the opening and closing handle outside the casting chamber, ensuring that the atmosphere in the casting chamber and the smelting furnace is not communicated with the outside world when adjusting the movable leakage mechanism.

[0027] Furthermore, the funnel buffer chamber includes a tank body, a tank cover and a rotating shaft passing through the tank cover, the rotating shaft is connected to a knob at one end outside the tank body, and the rotating shaft is connected to a blade for scraping the inner bottom surface of the tank body at one end inside the tank body, the inner bottom surface of the tank body is inclined relative to the horizontal plane, and a feeding hole leading to the crucible is provided on the higher side of the inner bottom surface of the tank body.

[0028] When preparing materials, electrolytic copper and metallic chromium can be directly placed in the crucible, and metallic zirconium can be placed on the lower side of the bottom of the tank body. When the smelting furnace is sealed, after the copper and chromium are melted, the knob is manipulated to rotate the blade around the rotation axis to scrape the metallic zirconium to the higher side of the bottom of the tank body, so that the metallic zirconium enters the crucible through the feeding hole. There is no need to open the furnace cover or the tank cover during the process.

[0029] Further, a mold inlet / outlet door is provided on the side of the pouring chamber. The mold inlet / outlet door is equipped with a sealed door panel. A first track extends outwardly downward from the pouring chamber. The sealed door panel is slidably connected to the first track. A second track is provided on the inner bottom surface of the pouring chamber. A mold base is slidably connected to the second track. The mold base is perpendicularly connected to the sealed door panel.

[0030] The beneficial effects of the present invention are as follows: When melting chromium metal and electrolytic copper, the present invention creates a vacuum environment to inhibit oxidation reactions and nitridation reactions, introduces an inert gas that is difficult to dissolve to restore normal pressure and delays the addition of zirconium metal, which can avoid the burning loss and volatilization of zirconium metal. The restored connected pouring chamber and melting furnace have a pressure difference, enabling the metal liquid with poor fluidity to quickly fall into the mold under the action of gravity and pressure difference. During the whole process, the materials are in a vacuum environment or an inert atmosphere, which can greatly reduce the surface oxidation of the finished product. Moreover, without a pouring device, it can save factory space.

[0031] Other features and advantages of the present application will be described in the subsequent specification. And, in part, they will become obvious from the specification, or can be understood by implementing the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures specifically pointed out in the written specification and the drawings. Brief Description of the Drawings

[0032] Figure 1 is one of the three-dimensional schematic diagrams of a device provided by an embodiment of the present application.

[0033] Figure 2 is the structural schematic diagram of a movable liquid leakage mechanism provided by an embodiment of the present application.

[0034] Figure 3 is the internal structural schematic diagram of the melting furnace and the pouring chamber.

[0035] Figure 4 is Figure 3 the enlarged view of part A in

[0036] Figure 5 is the second three-dimensional schematic diagram of a device provided by an embodiment of the present application.

[0037] Figure 6 is the three-dimensional view of the fixed plug at different perspectives.

[0038] Figure 7 is the three-dimensional view of the rotating plug at different perspectives.

[0039] Figure 8 is the three-dimensional view of the leakage tube.

[0040] Figure 9 is the internal structural schematic diagram of the funnel buffer chamber.

[0041] Figure 10 It is a schematic diagram of the internal structure of the crucible.

[0042] Figure 11 It is a cross-sectional view of the sample obtained in the implementation case.

[0043] Figure 12 It is Figure 11 a partial enlarged view of

[0044] Reference numerals in the drawings: 1, melting furnace; 12, partition; 121, bearing; 14, lifting mechanism; 2, pouring chamber; 21, mold inlet and outlet door; 22, sealing door panel; 23, first track; 24, mold base; 241, third track; 25, trolley; 26, telescopic mechanism; 27, observation window; 28, second track; 3, crucible; 31, liquid leakage port; 4, furnace cover; 41, funnel buffer chamber; 42, air guide port; 411, tank cover; 412, tank body; 413, blade; 414, knob; 415, feeding hole; 416, rotating shaft; 51, diversion opening and closing handle; 52, adjusting rod; 53, universal joint; 54, first bevel gear; 61, fixed plug; 611, upper diversion hole; 612, annular groove; 613, second annular groove; 62, rotating plug; 621, lower diversion hole; 622, convex ring; 623, square convex block; 624, cylinder; 63, diversion pipe; 631, second bevel gear; 633, second convex ring; 634, square pit. Detailed implementation manners

[0045] The following details the implementation manners of the present invention. Examples of the implementation manners are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The implementation manners described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0046] The following disclosure provides many different implementation manners or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various implementation manners and / or settings discussed.

[0047] The embodiment of the present application provides a method for vacuum induction melting and casting of copper-chromium-zirconium alloy, including the following steps:

[0048] S1: Put metallic chromium and electrolytic copper into the crucible in the melting furnace, and place metallic zirconium in the melting furnace and outside the crucible.

[0049] S2: Preheating the mold in a pouring chamber located below the melting furnace and connected to the melting furnace, and evacuating the melting furnace.

[0050] S3: Using a movable liquid leakage mechanism to isolate the melting furnace from the pouring chamber, heating by induction until the metal in the crucible is completely melted, introducing inert gas into the melting furnace to normal pressure; allowing the metal zirconium to fall into the crucible, and heat preservation by induction.

[0051] S4: Use the active liquid leakage mechanism to restore the connection between the smelting furnace and the pouring chamber so that the molten metal in the crucible leaks into the mold.

[0052] S5: terminate the induction heat preservation, introduce air into the smelting furnace to make the pouring chamber reach normal pressure, move the mold out of the pouring chamber, and obtain the formed copper-chromium-zirconium alloy in the mold.

[0053] Among them, "induction insulation" refers to insulation in the form of heating by electromagnetic induction.

[0054] After the raw materials are melted, a small amount of slag will float on the surface of the molten metal. When the traditional device pours the mold in the form of pouring, the slag is easily rolled into the mold cavity, reducing the quality uniformity and purity of the casting. After adopting the method of the present invention, the slag is on the top surface of the molten metal and finally leaks down, and at most only reaches the gate of the mold, which does not affect the quality of the casting.

[0055] In step S3, the metal zirconium is added into the crucible only after the copper and chromium added first are melted, which is beneficial to avoid burning of the metal zirconium. In step S1, the metal zirconium is first put into the smelting furnace but not in the crucible. In step S3, the metal zirconium can be put into the crucible without interacting with the external atmosphere, which can reduce material oxidation.

[0056] Liquid metal will dissolve gas at high temperature, and precipitate to form pores or cracks after cooling. A vacuum environment can significantly reduce the solubility of gases and reduce casting defects. Step S2 is to evacuate the gas to 1Pa~10Pa, and by extracting the gas in the furnace, the content of oxygen and nitrogen is reduced to extremely low levels, cutting off the contact between the liquid metal and the active gas. Highly active elements such as Cr can cause oxidation or nitridation even with trace amounts of oxygen or nitrogen. A vacuum environment can avoid such problems and remove volatile impurities.

[0057] In step S3, the zirconium is added into the crucible only after the inert gas (such as argon) is introduced to normal pressure, which is beneficial to reduce the volatilization of zirconium. The inert gas introduced in step S3 has low solubility, and the alloy will not precipitate to form pores or cracks after cooling.

[0058] The copper-chromium-zirconium alloy targeted by the present invention is a copper-chromium-zirconium alloy with Cu:Cr:Zr = 98.7 - 99:1:0.3 - 0.5. Since the copper liquid contains Cr, the fluidity of the molten metal becomes poor. At the moment when the connection between the melting furnace and the pouring chamber is restored in step S4, the inert gas filled in the previous step S3 just creates a pressure difference between the pouring chamber and the melting furnace, causing the flow rate of the molten metal to increase, making it not easy to adhere and block in the liquid leakage channel, and realizing the rapid and stable pouring of the molten metal.

[0059] The melting scale of the present invention is 500 kg - 6 t. The electrolytic copper of the raw material is in strip shape, and the metallic chromium and metallic zirconium are in granular shape. The preset power of inductive heating is 120 kW - 150 kW; during the process from the start of inductive heating to reaching the preset power, the power increase amplitude is 10 kW / min. Gradually increasing the power can avoid element volatilization caused by instant high temperature, and at the same time ensure the rapid melting of copper and chromium. Slowly increasing the heating power can reduce the thermal shock to the crucible and the mold, and extend the equipment life. Before starting the heating, the cooling water of the induction coil should be turned on first.

[0060] In step S3, the power of inductive heat preservation is 120 kW - 130 kW, and the time is 20 min - 30 min. Correspondingly, the graphite mold in the pouring chamber is preheated to 300 °C - 400 °C. The heat preservation in step S3 enables zirconium to fully diffuse with copper and chromium, reduces composition segregation, and maintains an appropriate temperature gradient between the mold and the pouring, avoiding local overheating or cold shut defects.

[0061] Refer to Figures 1 to 5 and Figure 10 To implement the above method, the embodiment of the present application further provides a device for the above method, including a pouring chamber 2, a melting furnace 1 with a furnace cover 4, and a crucible 3 arranged in the melting furnace 1. The pouring chamber 2 is connected to the bottom of the melting furnace 1. The bottom of the crucible 3 is provided with a liquid leakage port 31 and is connected with a movable liquid leakage mechanism. The movable liquid leakage mechanism is provided with two vertically stacked diversion holes. When the two diversion holes are aligned, the crucible 3 is connected to the pouring chamber 2. When the two diversion holes are staggered, the melting furnace 1 is isolated from the pouring chamber 2. The furnace cover 4 is provided with a gas guide port 42 and a funnel buffer chamber 41 for feeding materials into the crucible 3.

[0062] The air guide port 42 is used to evacuate in step S2, to introduce argon in step S3, and to introduce air in step S5. The funnel buffer chamber 41 is used to place the metal zirconium in the smelting furnace 1 and outside the crucible 3 in step S1, and not to heat the zirconium before the copper and chromium are melted, and to release the metal zirconium after the copper and chromium are melted and mixed, so that it falls into the crucible 3. The pouring chamber 2 and the smelting furnace 1 arranged up and down cooperate with the active liquid leakage mechanism to replace the dumping mechanism in the prior art, saving the device floor space. The two guide holes are aligned in step S1 to step S2 (the particle size of the metal chromium is larger than the inner diameter of the guide hole), and the smelting furnace 1 and the pouring chamber 2 can be evacuated at the same time when evacuating through the air guide port 42; the two guide holes are staggered in step S3 to prevent the molten metal from leaking into the mold before the metal zirconium is added; the two guide holes are aligned in step S4 to step S5, and the pressure difference is used to make the molten metal after electromagnetic heating and electromagnetic stirring leak into the mold, and then air is introduced into the smelting furnace 1 and the pouring chamber 2 through the air guide port 42.

[0063] In some embodiments, instruments such as a pressure gauge and a flow meter may be provided on the furnace cover 4, and the air guide port 42 may be connected to an air pipe, but these parts are not shown in the drawings.

[0064] Reference Figure 3 and Figure 4 A partition 12 is provided between the smelting furnace 1 and the pouring chamber 2 to separate the smelting furnace 1 and the pouring chamber 2. The movable leakage mechanism includes a guide tube 63 passing through the partition 12. The guide holes include an upper guide hole 611 fixed relatively to the crucible 3 and a lower guide hole 621 fixed relatively to the guide tube 63. The part of the guide tube 63 in the pouring chamber 2 is transmission-connected with a driving mechanism for driving the guide tube 63 to rotate around the axis of the guide tube 63. The axis of the guide tube 63 does not coincide with the guide hole.

[0065] By driving the guide tube 63 to rotate using a driving mechanism, the upper guide hole 611 and the lower guide hole 621 can be switched between the aligned and staggered states. Figure 3 The inductively heated coil and the water cooling device for cooling the coil are not shown, and these components are actually located in the cavity between the outer wall of the crucible 3 and the inner wall of the smelting furnace 1. In some embodiments, a bearing 121 is also provided in the center of the partition 12 to cooperate with the guide tube 63 to achieve the sealing of the smelting furnace 1 and the pouring chamber 2 and enable the guide tube 63 to rotate smoothly.

[0066] The above-mentioned driving mechanism can be an electric mechanism, and the embodiment of the present application also provides a specific method of manual adjustment. Figures 3 to 5, the driving mechanism includes an adjusting rod 52 passing through the pouring chamber 2. One end of the adjusting rod 52 outside the pouring chamber 2 is connected with a diversion opening and closing handle 51, and one end of the adjusting rod 52 inside the pouring chamber 2 is provided with a first bevel gear 54. A second bevel gear 631 meshing with the first bevel gear 54 is provided on the part of the diversion pipe 63 in the pouring chamber 2.

[0067] By rotating the handle outside the pouring chamber 2, the self-rotation of the diversion pipe 63 can be controlled, and the crucible 3 remains stationary throughout the process. Thus, the upper diversion hole 611 and the lower diversion hole 621 can be controlled to be aligned or staggered. Specifically, the adjusting rod 52 is connected to the first bevel gear 54 through a universal joint 53. When replacing the crucible 3 and disassembling the movable liquid leakage mechanism, the first bevel gear 54 can be swung downward to facilitate the disassembly of the movable liquid leakage mechanism. In some embodiments, an observation window 27 is provided on the pouring chamber 2 to facilitate observing the liquid leakage situation while operating the rotating handle and observing whether the lower end of the diversion pipe 63 is aligned with the pouring port of the mold.

[0068] Refer to Figure 6 , Figure 7 , Figure 8 and Figure 10 , Figure 6 , the view at point a in Figure 6 is the perspective of observing the fixed plug obliquely downward, and the view at point b in Figure 7 is the perspective of observing the fixed plug obliquely upward. The view at point a in Figure 7 is the perspective of observing the rotating plug obliquely downward, and the view at point b in

[0069] The inner bottom of the crucible 3 slopes downward from the outside to the center. The inner diameter of the liquid leakage port 31 gradually increases from top to bottom, and there is at least one turning angle formed due to the increase in the inner diameter on the inner wall of the liquid leakage port 31, such as the angle β in Figure 2 .

[0070] The upper part of the fixed plug 61 is a frustum of a cone, which cooperates with the liquid leakage port 31 with an inner diameter gradually increasing from top to bottom, increasing the friction between the crucible 3 and the fixed plug 61, and when cooperating with multiple alternative crucibles 3, it is easier to achieve a sealed connection. The lower part of the fixed plug 61 is approximately a cylinder. There is also a turning angle with the same angle as the angle β between the upper and lower parts of the fixed plug 61 to cooperate with the bottom of the crucible 3 to achieve a stronger sealed connection. The bottom of the fixed plug 61 is also provided with a second annular groove 613 outside the annular groove 612.

[0071] The upper part of the rotary plug 62 is a convex ring 622, the middle part is a square convex block 623, and the lower part is a cylinder 624. The cylinder 624 is used to insert into the upper end of the diversion pipe 63. A square pit 634 that cooperates with the square convex block 623 is also provided on the diversion pipe 63. A second convex ring 633 is provided at the top end of the diversion pipe 63 and is connected to the second annular groove 613. The fixed plug 61 and the rotary plug 62 are abutted against each other up and down so that the lower edge of the upper diversion hole 611 and the upper edge of the lower diversion hole 621 are on the same horizontal plane.

[0072] In this way, when the fixed plug 61, the rotary plug 62, and the diversion pipe 63 are connected, a good sealing effect is achieved, and the diversion pipe 63 can drive the rotary plug 62 to rotate and slide relative to the fixed plug 61.

[0073] Referring to Figure 9 , the funnel buffer chamber 41 includes a tank body 412, a tank cover 411, and a rotating shaft 416 passing through the tank cover 411. One end of the rotating shaft 416 outside the tank body 412 is connected with a knob 414, and one end of the rotating shaft 416 inside the tank body 412 is connected with a blade 413 for scraping the inner bottom surface of the tank body 412. The inner bottom surface of the tank body 412 is inclined relative to the horizontal plane. A feeding hole 415 leading to the crucible 3 is opened on the higher side of the inner bottom surface of the tank body 412.

[0074] Among them, the "higher side" means that: since the inner bottom surface of the tank body 412 is inclined relative to the horizontal plane, the inner bottom surface of the tank body 412 is not on the same horizontal plane. A hypothetical horizontal plane is established through the bottom end of the rotating shaft 416. The part higher than this horizontal plane is called the higher side, and the part lower than this horizontal plane becomes the lower side.

[0075] By manually operating the knob 414, the zirconium metal particles pre-placed on the lower side of the inner bottom surface of the tank body 412 can be scraped to the feeding hole 415. The overall height of this device is about 5 meters. In fact, a working platform will be built around this device to facilitate workers to feed materials, and the working platform is not drawn in the attached drawings. A jacking mechanism 14 is provided on the side of the melting furnace 1. The jacking mechanism 14 can be a hydraulic cylinder. After a round of pouring is completed, control the jacking mechanism 14 to lift the furnace cover 4 until the furnace cover 4 is not in contact with the melting furnace 1. The furnace cover 4 is rotatably connected to the jacking mechanism 14, and the furnace cover 4 can be pushed open to rotate around the jacking mechanism 14, thereby exposing the crucible 3, which is convenient for directly adding electrolytic copper and chromium metal. And zirconium metal is added to the lower side of the inner bottom surface of the tank body 412 by opening the tank cover 411 of the funnel buffer chamber 41. Here, only one form of opening the furnace cover 4 is exemplified. In fact, structures such as a sliding cover and a hinged cover can also be adopted.

[0076] Referring to Figure 1 and Figure 5, a mold inlet / outlet door 21 is provided on the side of the pouring chamber 2. The mold inlet / outlet door 21 is equipped with a sealing door panel 22. A first track 23 extends outward (horizontally away from the pouring chamber 2) from the lower direction of the pouring chamber 2. The sealing door panel 22 is slidably connected to the first track 23. A second track 28 is provided on the inner bottom surface of the pouring chamber 2. A mold base 24 is slidably connected to the second track 28. The mold base 24 is perpendicularly connected to the sealing door panel 22.

[0077] A hydraulic cylinder can be provided between the sealing door panel 22 and the pouring chamber 2 for opening and closing the door. When opening the door, the sealing door panel 22 slides along the first track 23, and the mold base 24 slides along the second track 28. In some embodiments, the mold can be directly placed on the mold base 24, and the mold can be equipped with a mold heating system. However, due to the structure of this device, there is no connection relationship between the diversion pipe 63 and the mold. If the mold is directly placed on the mold base 24, it is difficult to ensure that the end of the diversion pipe 63 is exactly aligned with the pouring port after closing the door.

[0078] In a preferred embodiment, a trolley 25 for carrying the mold is provided on the mold base 24. A third track 241 for the trolley 25 to slide is provided on the mold base 24. A telescopic mechanism 26 for driving the trolley 25 is provided through the sealing door panel 22. In this way, the telescopic mechanism 26 can be controlled after closing the door, so as to adjust the position of the trolley 25 and finely adjust the position of the mold relative to the diversion pipe 63. More preferably, the mold is a multi-cavity mold, and there is a flow groove between adjacent pouring ports. The telescopic mechanism 26 is signal-connected to the controller, so that after one cavity is filled (it can be judged whether it is full according to the liquid leakage time), the trolley 25 is automatically controlled to move the mold so that the next pouring port is aligned with the end of the diversion pipe 63, and the liquid leakage pouring continues until all cavities are filled.

[0079] Implementation case

[0080] Prepare raw materials electrolytic copper, metal chromium, and metal zirconium, and the element ratio is Cu:Cr:Zr = 98.7:1:0.3.

[0081] Open the vacuum induction melting furnace, and put electrolytic copper and metal Cr into the graphite crucible; the metal Zr block is placed in the funnel buffer chamber inside the furnace cover, which is convenient for leaking into the graphite crucible for melting before pouring, and then close the melting furnace and the pouring chamber.

[0082] Turn on the cooling water of the induction coil, turn on the graphite mold heating system in the pouring chamber, preheat the graphite mold to 350 ± 20 °C and then keep it warm. The mold is a three-cavity mold. Open the air extraction valve connected to the air guide port, and evacuate the melting furnace and the pouring chamber simultaneously. Stop evacuating when it reaches 10 Pa, and rotate the diversion pipe so that the upper diversion hole and the lower diversion hole are staggered.

[0083] Turn on the heating system to heat the metal in the crucible, slowly increase the power of the induction copper coil to 150 kW. After the metal is completely melted, introduce argon gas into the melting furnace. After the pressure inside the melting furnace is balanced with the external pressure, open the funnel buffer chamber inside the furnace cover, and let the Zr metal block leak into the graphite crucible. Control the power at 120 kW and keep it warm for 20 minutes.

[0084] Rotate the diversion tube to connect the upper diversion hole and the lower diversion hole, and let the molten metal flow from the bottom of the graphite crucible into the graphite mold in the pouring chamber. After the first pouring port of the graphite mold is filled, the trolley automatically moves to the next pouring port and aligns with the end of the diversion tube until all cavities are filled.

[0085] Open the intake valve of the melting furnace to allow argon gas and air to enter the pouring chamber. After the pressure inside the pouring chamber is balanced with the external pressure, open the sealed door panel, and the mold is synchronously removed from the pouring chamber.

[0086] The castings obtained in this embodiment are as Figure 11 and Figure 12 shown. As can be seen from Figure 11 , the texture of the castings is uniform, and there are no cracks or pores inside; as can be seen from Figure 12 , the thickness of the black oxide layer on the surface of the castings is extremely low, which proves that the surface oxidation of the copper-chromium-zirconium alloy castings obtained by this method and device is very little.

[0087] In the description of this specification, the descriptions referring to terms such as "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the said embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0088] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A vacuum induction melting and casting method for copper-chromium-zirconium alloy, characterized in that: The following steps are involved: Putting metallic chromium and electrolytic copper into a crucible in a smelting furnace, and placing metallic zirconium in the smelting furnace and outside the crucible; preheating a mold in a pouring chamber located below the smelting furnace and in communication with the smelting furnace, and evacuating the smelting furnace; The smelting furnace and the pouring chamber are isolated by a movable liquid leakage mechanism, and the metal in the crucible is completely melted by induction heating, and an inert gas is introduced into the smelting furnace to a normal pressure; the metal zirconium is allowed to fall into the crucible, and the temperature is kept by induction; The movable liquid leakage mechanism is used to restore the connection between the smelting furnace and the pouring chamber, so that the molten metal in the crucible leaks into the mold; The induction heat preservation is terminated, air is introduced into the smelting furnace to make the casting chamber reach normal pressure, the mold is moved out of the casting chamber, and a formed copper-chromium-zirconium alloy is obtained in the mold.

2. The vacuum induction melting and casting method of copper-chromium-zirconium alloy according to claim 1, characterized in that: The preset power of the induction heating is 120kW~150kW; from the time the induction heating is turned on to the time the preset power is reached, the power increases by 10kW / min.

3. The vacuum induction melting and casting method of copper-chromium-zirconium alloy according to claim 2, characterized in that: Before the smelting furnace and the pouring chamber are restored to be connected, the power of the inductive insulation is 120 kW to 130 kW, and the time is 20 min to 30 min.

4. An apparatus for the vacuum induction melting and casting method of copper-chromium-zirconium alloy according to any one of claims 1 to 3, comprising a pouring chamber, a melting furnace with a furnace cover and a crucible arranged in the melting furnace, characterized in that: The pouring chamber is connected to the bottom of the smelting furnace, a liquid leakage port is provided at the bottom of the crucible and is connected to a movable liquid leakage mechanism, two guide holes stacked up and down are provided in the movable liquid leakage mechanism, the two guide holes connect the crucible and the pouring chamber when aligned, and the two guide holes isolate the smelting furnace and the pouring chamber when staggered, and the furnace cover is provided with an air guide port and a funnel buffer chamber for feeding materials into the crucible.

5. The device according to claim 4, characterized in that A partition is provided between the smelting furnace and the pouring chamber to separate the two, the movable liquid leakage mechanism includes a guide tube passing through the partition, the guide holes include an upper guide hole fixed relatively to the crucible and a lower guide hole fixed relatively to the guide tube, the part of the guide tube in the pouring chamber is transmission-connected with a driving mechanism for driving the guide tube to rotate around the axis of the guide tube, and the axis of the guide tube does not coincide with the guide hole.

6. The device according to claim 5, characterized in that The movable liquid leakage mechanism also includes a fixed plug for blocking the liquid leakage port and a rotating plug for blocking the upper end of the guide tube, the upper guide hole is arranged through the fixed plug, the lower guide hole is arranged through the rotating plug, the fixed plug and the rotating plug are abutted against each other up and down, at least one annular groove recessed upward is arranged at the bottom of the fixed plug, and a convex ring matching the annular groove is arranged at the top of the rotating plug.

7. The device according to claim 6, characterized in that The inner bottom of the crucible is inclined downward from the outside to the center, the inner diameter of the liquid leakage port is gradually expanded from top to bottom, and the inner wall of the liquid leakage port has at least one turning angle formed by the expansion of the inner diameter.

8. The device according to claim 5, characterized in that The driving mechanism includes an adjusting rod passing through the pouring chamber, wherein the adjusting rod is connected to a diversion opening and closing handle at one end outside the pouring chamber, a first bevel tooth is provided at one end of the adjusting rod inside the pouring chamber, and a second bevel tooth meshing with the first bevel tooth is provided at the portion of the diversion pipe in the pouring chamber.

9. The device according to claim 4, characterized in that The funnel buffer chamber includes a tank body, a tank cover and a rotating shaft passing through the tank cover, the rotating shaft is connected to a knob at one end outside the tank body, and the rotating shaft is connected to a blade for scraping the inner bottom surface of the tank body at one end inside the tank body. The inner bottom surface of the tank body is inclined relative to the horizontal plane, and a feeding hole leading to the crucible is provided on the higher side of the inner bottom surface of the tank body.

10. The device according to claim 4, characterized in that A mold entrance door is provided on the side of the pouring chamber, and the mold entrance door is equipped with a sealing door panel. A first track extends outward from the bottom of the pouring chamber, and the sealing door panel is slidably connected to the first track. A second track is provided on the inner bottom surface of the pouring chamber, and a mold base is slidably connected to the second track, and the mold base is vertically connected to the sealing door panel.

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