Vacuum induction casting forming method and device for copper-chromium-zirconium alloy

Abstract

The invention discloses a copper-chromium-zirconium alloy vacuum induction casting forming method and device, and belongs to the field of alloy casting, and the method comprises the following steps: metal chromium and electrolytic copper are put into a crucible, a smelting furnace and a pouring chamber are isolated after vacuumizing, heating is carried out until metal in the crucible is molten, inert gas is introduced into the smelting furnace, metal zirconium in the smelting furnace falls into the crucible, and heat preservation is carried out; and the smelting furnace and the pouring chamber are communicated again, and the molten metal leaks into the mold. When metal chromium and electrolytic copper are melted, oxidation reaction and nitridation reaction are inhibited in a vacuum environment, inert gas is introduced, and metal zirconium is delayed to be added, so that the metal zirconium can be prevented from being burnt and volatilized, and the pressure difference between a communicated pouring chamber and a smelting furnace is recovered, so that molten metal can quickly leak into a mold under the action of gravity and the pressure difference; in the whole process, materials are not communicated with the outside, casting surface oxidation can be greatly reduced, slag floating on the surface of molten metal cannot enter a mold, the casting quality is greatly improved, a dumping device is not needed, and the workshop space is saved.

Description

Technical Field

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

[0002] In the prior art, when casting copper-chromium-zirconium alloy, vacuum melting and casting process is usually adopted. Metal raw materials such as copper, chromium and zirconium are melted under vacuum conditions, which can reduce the oxidation of alloy elements and accurately control the alloy composition. The molten metal is then 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 and complex copper-chromium-zirconium alloy castings, such as conductive parts in some large electrical equipment.

[0003] There are still some disadvantages when casting copper-chromium-zirconium alloy with the current vacuum melting and casting process. The vacuum melting and casting process is suitable for manufacturing large castings weighing hundreds of kilograms to several tons, so the volume of the molten metal is also large. The molten metal is poured into the mold by pouring, which means that the mechanical parts related to the pouring operation also have a considerable volume, and enough space must be left to avoid the overturned crucible, resulting in the melting and casting device consuming a lot of plant space and occupying too much floor space. Moreover, although melting metal under vacuum conditions can reduce the oxidation of alloy elements, there is still a long time for the molten metal to contact the outside air during pouring, and the actual casting has a thicker oxide layer. At the same time, part of the 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 copper-chromium-zirconium alloy vacuum induction melting and casting method and device, which can reduce the oxidation of the copper-chromium-zirconium alloy and save plant space.

[0005] The technical solution adopted by the present invention to solve its technical problem is: In a first aspect, the present application provides a copper-chromium-zirconium alloy vacuum induction melting and casting method, comprising the following steps: 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.

[0006] The copper-chromium-zirconium alloy vacuum induction melting and casting method provided by the present application creates a vacuum environment to inhibit oxidation reaction and nitridation reaction, remove volatile impurities, delay the addition of metal zirconium, and introduce an insoluble inert gas to restore normal pressure before adding the metal zirconium, which can avoid the burning of metal zirconium and inhibit the volatilization of metal zirconium. The inert gas filled in just forms a pressure difference with the casting chamber under negative pressure during the 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 to fill the mold. During the whole process, the material is in a vacuum environment or an inert atmosphere, which can greatly reduce the oxidation of the surface of the finished product, and because 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, which greatly improves the quality of the casting. Furthermore, the present invention does not require a dumping device, which can save factory space.

[0007] Furthermore, the preset power of the induction heating is 120kW~150kW; and during the process from the induction heating being turned on to reaching the preset power, the power increase amplitude is 10kW / min.

[0008] The induction heating parameters ensure that copper and chromium are fully melted and fully mixed under the action of electromagnetic stirring. Gradually increasing the induction heating power to the preset power can avoid metal vaporization and help extend the life of the equipment.

[0009] Furthermore, 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.

[0010] The use of this heat preservation parameter can ensure that the zirconium added later can also be fully melted and evenly mixed with the copper liquid, and the burning and volatilization of zirconium can be avoided.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] Furthermore, a mold entrance door is opened 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. The mold base is vertically connected to the sealing door panel.

[0024] The beneficial effects of the present invention are as follows: when melting metal chromium and electrolytic copper, the present invention creates a vacuum environment to inhibit oxidation reaction and nitridation reaction, introduces inert gas that is difficult to dissolve to restore normal pressure and delays the addition of metal zirconium, thereby avoiding burning and volatilization of metal zirconium, and restoring the pressure difference between the connected pouring chamber and the smelting furnace, so that the metal liquid with poor fluidity can quickly fall into the mold under the action of gravity and pressure difference. During the whole process, the material is in a vacuum environment or an inert atmosphere, which can greatly reduce the surface oxidation of the finished product, and no dumping device is required, which can save plant space.

[0025] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is one of the three-dimensional schematic diagrams of a device provided in an embodiment of the present application.

[0027] Figure 2 It is a structural schematic diagram of an active liquid leakage mechanism provided in an embodiment of the present application.

[0028] Figure 3 It is a schematic diagram of the internal structure of the smelting furnace and pouring chamber.

[0029] Figure 4 yes Figure 3 Enlarged view of point A in the middle.

[0030] Figure 5 This is the second stereoscopic schematic diagram of a device provided in an embodiment of the present application.

[0031] Figure 6 It is a stereoscopic image of the fixed plug at different viewing angles.

[0032] Figure 7 It is a stereoscopic image of the rotary plug at different viewing angles.

[0033] Figure 8 It is a stereogram of the leakage pipe.

[0034] Fig. 9 It is a schematic diagram of the internal structure of the funnel cache chamber.

[0035] Fig.10 It is a schematic diagram of the internal structure of the crucible.

[0036] Fig.11 This is a cross-sectional view of a sample obtained in the implementation case.

[0037] Fig.12 yes Fig.11 A partial enlarged view of .

[0038] Reference numerals: 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 protrusion; 624, cylinder; 63, diversion tube; 631, second bevel gear; 633, second convex ring; 634, square pit. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0041] The present application provides a vacuum induction melting and casting method for a copper-chromium-zirconium alloy, comprising the following steps: S1: 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.

[0042] S2: Preheating the mold in a pouring chamber located below the melting furnace and connected to the melting furnace, and evacuating the melting furnace.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Among them, "induction insulation" refers to insulation in the form of heating by electromagnetic induction.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The copper-chromium-zirconium alloy targeted by the present invention is a copper-chromium-zirconium alloy with a Cu:Cr:Zr=98.7~99:1:0.3~0.5. Since the copper liquid contains Cr, the fluidity of the metal liquid deteriorates. At the moment when the connection between the smelting furnace and the pouring chamber is restored in step S4, the inert gas filled in the previous step S3 just forms a pressure difference between the pouring chamber and the smelting furnace, so that the flow rate of the metal liquid is accelerated, and it is not easy to stick and block in the leakage channel, so that the metal liquid can be poured quickly and smoothly.

[0052] The smelting scale of the present invention is 500kg~6t, the raw material electrolytic copper is in strip form, and the metal chromium and metal zirconium are in granular form. The preset power of induction heating is 120kW~150kW; from the start of induction heating to the reaching of the preset power, the power increase is 10kW / min. Gradually increase the power to avoid the volatilization of elements caused by instantaneous high temperature, while ensuring the rapid melting of copper and chromium. Slowly increasing the heating power can reduce the thermal shock to the crucible and mold, and extend the life of the equipment. Before turning on the heating, the cooling water of the induction coil should be turned on first.

[0053] In step S3, the power of the inductor insulation is 120kW~130kW, and the time is 20min~30min. Correspondingly, the graphite mold in the casting chamber is preheated to 300℃~400℃. In step S3, the insulation allows zirconium, copper and chromium to diffuse fully, reduces component segregation, and maintains an appropriate temperature gradient between the mold and the casting to avoid local overheating or cold shut defects.

[0054] Reference Figures 1 to 5 ,as well as Fig.10 To implement the above method, the embodiment of the present application further provides a device for the above method, comprising a pouring chamber 2, a smelting furnace 1 with a furnace cover 4 and a crucible 3 arranged in the smelting furnace 1, the pouring chamber 2 is connected to the bottom of the smelting furnace 1, a liquid leakage port 31 is provided at the bottom of the crucible 3 and is connected to a movable liquid leakage mechanism, and two guide holes stacked up and down are provided in the movable liquid leakage mechanism, the two guide holes are connected to the crucible 3 and the pouring chamber 2 when they are aligned, and the two guide holes are separated from the smelting furnace 1 and the pouring chamber 2, and 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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, and one end of the adjusting rod 52 outside the pouring chamber 2 is connected to 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 tooth 54, and the part of the diversion tube 63 in the pouring chamber 2 is provided with a second bevel tooth 631 meshing with the first bevel tooth 54.

[0060] By rotating the handle outside the pouring chamber 2, the flow guide tube 63 can be controlled to rotate, and the crucible 3 is stationary throughout the process, thereby controlling the alignment or stagger of the upper flow guide hole 611 and the lower flow guide hole 621. Specifically, the adjustment rod 52 is connected to the first bevel gear 54 through a universal joint 53. When the crucible 3 is replaced and the movable leakage mechanism is disassembled, the first bevel gear 54 can be swung downward to facilitate the disassembly of the movable leakage mechanism. In some embodiments, an observation window 27 is provided on the pouring chamber 2, which is convenient for observing the leakage while operating the rotating handle and observing whether the lower end of the flow guide tube 63 is aligned with the pouring port of the mold.

[0061] Reference Figure 6 , Figure 7 , Figure 8 and Fig.10 , Figure 6 The middle a is the angle of view of the fixed plug when looking down diagonally. Figure 6 Point b in the middle is the angle of view for observing the fixed plug obliquely upward. Figure 7 The middle a is the angle of view of the rotating plug when looking down diagonally. Figure 7Point b in the middle is the perspective for observing the rotating plug obliquely upward. The movable leakage mechanism also includes a fixed plug 61 for sealing the leakage port 31 and a rotating plug 62 for sealing the upper end of the guide tube 63. The upper guide hole 611 is penetrated on the fixed plug 61, and the lower guide hole 621 is penetrated on the rotating plug 62. The fixed plug 61 and the rotating plug 62 are abutted against each other up and down. At least one upwardly recessed annular groove 612 is provided at the bottom of the fixed plug 61, and a convex ring 622 matching the annular groove 612 is provided at the top of the rotating plug 62.

[0062] The inner bottom of the crucible 3 is inclined downward from the outside to the center, the inner diameter of the leakage port 31 gradually increases from top to bottom, and the inner wall of the leakage port 31 has at least one turning angle formed by the increase of the inner diameter, such as Figure 2 Median angle β.

[0063] The upper part of the fixed plug 61 is a frustum, which cooperates with the leakage port 31 whose inner diameter gradually expands from top to bottom, increases the friction between the crucible 3 and the fixed plug 61, and is easier to achieve a sealed connection when it cooperates with multiple alternative crucibles 3. The lower part of the fixed plug 61 is approximately a cylinder, and there is also a turning angle between the upper and lower parts of the fixed plug 61, which is equal to the angle β and cooperates with the bottom of the crucible 3 to achieve a more sealed connection. The bottom of the fixed plug 61 is also provided with a second annular groove 613 on the periphery of the annular groove 612.

[0064] The upper part of the rotating 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 the upper end of the guide tube 63. The guide tube 63 is also provided with a square pit 634 that cooperates with the square convex block 623. The top of the guide tube 63 is provided with a second convex ring 633 connected to the second annular groove 613, and the fixed plug 61 and the rotating plug 62 are abutted against each other up and down so that the lower edge of the upper guide hole 611 and the upper edge of the lower guide hole 621 are on the same horizontal plane.

[0065] In this way, the fixed plug 61 , the rotating plug 62 and the flow guide tube 63 have a good sealing effect when connected, and the flow guide tube 63 can drive the rotating plug 62 to rotate and slide relative to the fixed plug 61 .

[0066] Reference Fig. 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 to a knob 414, and one end of the rotating shaft 416 inside the tank body 412 is connected to 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, and a feeding hole 415 leading to the crucible 3 is provided on the higher side of the inner bottom surface of the tank body 412.

[0067] Here, "the higher side" means: 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, and an imaginary horizontal plane is established through the bottom end of the rotating shaft 416. The part higher than the horizontal plane is called the higher side, and the part lower than the horizontal plane is called the lower side.

[0068] By manually operating the knob 414, the metal zirconium particles pre-placed on the lower side of the bottom surface of the tank body 412 can be scraped to the feeding hole 415. The device is about 5 meters high as a whole. In fact, a working platform will be built around the device to facilitate workers to feed materials, but the working platform is not drawn in the attached figure. A lifting mechanism 14 is arranged on the side of the smelting furnace 1. The lifting mechanism 14 can be a hydraulic cylinder. After completing a round of pouring, the lifting mechanism 14 is controlled to lift the furnace cover 4 until the furnace cover 4 is not in contact with the smelting furnace 1. The furnace cover 4 is rotatably connected to the lifting mechanism 14, and the furnace cover 4 can be pushed open to rotate around the lifting mechanism 14, thereby exposing the crucible 3, which is convenient for directly adding electrolytic copper and metal chromium. The metal zirconium opens the tank cover 411 of the funnel buffer chamber 41 and is added to the lower side of the bottom surface of the tank body 412. Here, only one form of opening the furnace cover 4 is given as an example. In fact, structures such as sliding cover and lifting cover can also be used.

[0069] Reference Figure 1 and Figure 5 A mold inlet and outlet door 21 is provided on the side of the pouring chamber 2, and the mold inlet and outlet door 21 is provided with a sealing door plate 22. A first track 23 extends outward from the bottom of the pouring chamber 2 (horizontally away from the pouring chamber 2), and the sealing door plate 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, and a mold base 24 is slidably connected to the second track 28, and the mold base 24 is vertically connected to the sealing door plate 22.

[0070] A hydraulic cylinder may be provided between the sealing door plate 22 and the pouring chamber 2 for opening and closing the door. When the door is opened, the sealing door plate 22 slides along the first track 23, and the mold base 24 slides along the second track 28. In some embodiments, the mold may be placed directly on the mold base 24, and the mold may be equipped with a mold heating system. However, due to the structure of the device, there is no connection between the guide tube 63 and the mold. If the mold is placed directly on the mold base 24, it is difficult to ensure that the end of the guide tube 63 is aligned with the pouring port after the door is closed.

[0071] 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, and a telescopic mechanism 26 for driving the trolley 25 is provided through the sealed door panel 22. In this way, the telescopic mechanism 26 can be controlled after the door is closed to adjust the position of the trolley 25 and fine-tune the position of the mold relative to the guide tube 63. More preferably, the mold is a multi-cavity mold with a flow groove between adjacent pouring ports, and the telescopic mechanism 26 is connected to the controller signal so that after pouring a cavity (whether it is full can be judged based on the leakage time), the trolley 25 is automatically controlled to move the next pouring port of the mold to align with the end of the guide tube 63, and continue the leakage pouring until all cavities are filled.

[0072] Implementation Cases Prepare raw materials of electrolytic copper, metallic chromium and metallic zirconium, with the element ratio of Cu:Cr:Zr=98.7:1:0.3.

[0073] Open the vacuum induction melting furnace, put the electrolytic copper and metal Cr into the graphite crucible; put the metal Zr block into the funnel buffer chamber in the furnace cover to facilitate melting in the graphite crucible before pouring, and close the melting furnace and pouring chamber.

[0074] 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℃ and then keep it warm. The mold is a three-cavity mold. Open the exhaust valve connected to the air guide port, evacuate the melting furnace and the pouring chamber at the same time, stop when the vacuum reaches 10Pa, and rotate the guide tube to stagger the upper guide hole and the lower guide hole.

[0075] Turn on the heating system to heat the metal in the crucible, slowly increase the power of the induction copper coil to 150kW, and after the metal is completely melted, pass argon gas into the smelting furnace until the pressure of the smelting furnace is balanced with the external air pressure, then open the funnel buffer chamber in the furnace cover, and let the metal Zr block leak into the graphite crucible. Control the power at 120kw and keep warm for 20min.

[0076] Rotate the guide tube to connect the upper guide hole with the lower guide hole, allowing the molten metal to 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 cart automatically moves to the next pouring port and aligns it with the end of the guide tube until all cavities are filled.

[0077] Open the air inlet valve of the melting furnace to allow argon and air to enter the pouring chamber. After the pressure in the pouring chamber is balanced with the external air pressure, open the sealing door panel and move the mold out of the pouring chamber simultaneously.

[0078] The castings obtained in this embodiment are as follows: Fig.11 and Fig.12 As shown, from Fig.11 It can be seen that the casting has uniform texture and no cracks or pores inside. Fig.12 It can be seen that the thickness of the black oxide layer on the surface of the casting is extremely low, proving that the surface oxidation of the copper-chromium-zirconium alloy casting produced by the method and device is very little.

[0079] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0080] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection 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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