CN102806329A - Continuous blank casting system capable of performing semi-solid processing on non-ferrous alloy - Google Patents

Abstract

A non-ferrous alloy continuous blank casting system capable of semi-solid processing is composed of a die-casting chamber capable of semi-solid processing, a non-ferrous alloy liquid storage chamber, an induction heater, a non-ferrous alloy liquid injection chamber, a liquid discharge hole and a The non-ferrous alloy pump connects the holding furnace device of the melting casting room and the alloy liquid storage room through a tunnel, and another system consisting of a crystallizer device with a pulse agitator and a water cooling system. Crystals solidify. The system works stably, and can eliminate defects such as segregation and shrinkage porosity of large-diameter billets, so that high-quality non-ferrous alloy billets can be obtained, and the production of high-quality non-ferrous alloy continuous ingots can be realized.

Description

A non-ferrous alloy continuous billet casting system capable of semi-solid processing

technical field

The invention belongs to the liquid processing and forming technology of metal materials, in particular to the high-performance semi-solid processing and forming technology of various metal materials.

The invention also belongs to the technology of continuous billet casting of metal materials, especially the technology of continuous billet casting of non-ferrous alloys.

Background technique

The development of modern science and technology has put forward higher and higher requirements for the performance of various high-performance special-shaped components. Semi-solid processing technology can refine the grains of metal materials and obtain fine, nearly spherical, non-dendritic structures, thereby greatly improving the mechanical properties of workpieces, especially improving the performance of various high-performance special-shaped components and reducing processing costs. significance.

There is an increasing demand for non-ferrous metal materials such as copper, aluminum, magnesium, zinc and other alloys, especially copper alloys, but due to the high price of copper alloys, magnesium, aluminum, and zinc are more common metals, second only to iron, Aluminum and copper, and many properties of zinc are similar to copper, so more and more attention has been paid by the industry.

Horizontal continuous casting has the advantages of short process flow, good quality, low investment and fast start-up. The invention has important significance for promoting the application of non-ferrous alloy materials, especially for improving the performance of zinc alloy. the

The semi-solid processing technology of metal materials is a key technology in the precise forming technology of various high-performance components, which directly affects the performance quality of various high-performance special-shaped components, "New Technology for Preparation and Processing of Semi-solid Metal Paste" ( Jiang Yunxi, Xie Shuisheng, Li Xinggang, "Forging Technology" 28.6 in 2003), disclosed the current development of semi-solid processing technology at home and abroad.

The traditional semi-solid processing methods mainly include:

(1) New MIT process The "new MIT process" method was proposed by Flemings of the Massachusetts Institute of Technology (MIT) in 2000, and Idraprince Co., Ltd. obtained the patent for this technology. The principle is that at the liquidus temperature of the alloy solution, due to the joint action of stirring and cooling, the supercooled nucleation of the alloy grains in the solution volume is caused, and then the alloy solution is rapidly cooled to obtain a more ideal semi-solid slurry , and then injected into the cavity to form.

(2) cooling chute method  The principle of the cooling chute method is: pour the molten metal slightly higher than the liquidus temperature on the cooling chute, due to the cooling effect of the chute, there are fine grains nucleate and grow on the chute wall, and the metal fluid The impact of the impact and the self-weight of the material make the grains fall off the wall of the chute and turn over to achieve the stirring effect. The metal slurry that passes through the cooling chute falls into the container, and the temperature of the container is controlled, that is, it is cooled slowly. After cooling to a certain semi-solid temperature, it is kept warm to reach the required solid phase volume fraction, and then rheological deformation and thixotropic deformation can be performed. .

(3) Double-helix semi-solid metal rheological injection molding method The working principle of this method is that molten metal is melted in a crucible to a predetermined temperature about 50°C higher than the liquidus temperature, and the molten metal is kept warm for 15 minutes to obtain Uniform chemical composition. When the molten metal is magnesium alloy, the crucible is protected by argon gas. The molten metal enters the twin-screw shearing device at a certain speed, adjusts its temperature, and is sheared by the twin-screw at the same time to obtain an ideal semi-solid slurry with a certain percentage of solid phase.

(4) Shearing-cooling-rolling method The working principle of this method is: the molten metal heated to a certain temperature is injected into the guide groove above the roll gap through the nozzle, and a certain gap is left between the roll and the shoe seat. At the same time, the surface of the roll has a certain roughness, and the inside of the roll is cooled by water. Due to the cooling effect of the roll and the shoe-shaped seat, the alloy liquid solidifies, and the rotating roll produces shear and agitation on the partially solidified alloy, so that the alloy liquid is converted into a semi-solid slurry, and the semi-solid slurry is separated by the friction force exerted by the roll. The material is dragged out from the gap between the roller and the shoe seat, and the semi-solid slurry is guided to flow through the stripper installed at the discharge port. It can be rheologically formed directly, or it can be made into a semi-solid billet of the required size, and then thixoformed.

(5) NRC process  The production process of the NRC method is as follows: ① Control the molten metal within a few degrees above the liquidus temperature; ② Pour the molten metal into a heat-insulated container. Due to the cooling effect of the container, a large number of primary phases are generated inside the molten metal. ③ Cover the container with ceramics to prevent overcooling; ④ Use air cooling to cool the metal to the set semi-solid temperature; ⑤ Adjust the temperature of the slurry through the high-frequency induction heater outside the heat-insulated container to adjust the metal The solid phase volume fraction of the slurry forms a spherical slurry to meet the forming needs. This process takes 3 to 5 minutes; ⑥Turn over the heat-insulated container and pour the semi-solid slurry into the sleeve. At the same time, the oxide layer on the upper surface sinks to the bottom of the sleeve, which can prevent the oxide layer from entering the product; ⑦ Pour the slurry directly into the mold cavity and form it.

(6) Different liquid mixing method The different liquid mixing method is to mix two or three molten metals of hypoeutectic composition, or to mix molten metals of hypoeutectic and hypereutectic composition, and keep the molten metals to be mixed above the liquidus line, and the molten metal There are no crystal nuclei or few crystal nuclei. The mixing is carried out in an insulated container, or in a static mixing tank that is coated with graphite on the surface of the insulated container. The mixing tank should be preheated to ensure that the temperature of the melt is maintained at the liquidus temperature when it flows through the mixing tank. above. The melt flows in a turbulent manner on the mixing tank, which makes it well mixed. The mixing of the two melts leads to spontaneous heat conduction (heat release), the hypoeutectic absorbs the heat of the hypereutectic, and the temperature of the new alloy obtained after mixing is above and below the liquidus temperature, containing a large number of crystal nuclei, and further heat treatment can be formed. , a semi-solid slurry of spherical tissue.

(7) Near-liquidus casting method The near-liquidus casting method mainly uses factors such as controlling the casting temperature, standing time, casting speed and cooling intensity to make the melting temperature above the liquidus temperature or close to the liquidus temperature After standing for heat preservation, it is poured at a certain cooling rate to obtain a fine, nearly spherical, non-dendritic semi-solid structure.

The new processes introduced above are all semi-solid rheological forming technologies. The current semi-solid processing technology can be divided into semi-solid rheological forming and semi-solid thixoforming. It is made into semi-solid slurry, and then rheological or thixotropic forming process is carried out. The rheological forming process is to directly cast and roll the prepared semi-solid slurry into a slab, and the thixoforming process is to cast the prepared semi-solid slurry into an ingot, then heat it again, and remelt it. The process of thixoforming. The main problem of the current semi-solid rheological technology is that a semi-solid cooling and pulping process is required before casting, which requires strict temperature control and certain pulping equipment, which greatly increases the manufacturing cost and process complexity.

The advantages of horizontal continuous casting are short process, low process cost, high production efficiency, and small footprint. It is often used for non-ferrous metal alloy materials with poor thermal processing performance.

Contents of the invention

The purpose of this invention is to design a new non-ferrous metal continuous casting device capable of semi-solid processing, which can make non-ferrous alloy metal liquid crystallize and solidify after semi-solid processing, thereby eliminating the difficulty of traditional continuous casting of large-diameter billets. Defects such as segregation, shrinkage porosity, and coarse crystal dendrites are produced to obtain high-quality non-ferrous alloy casting embryos.

The general technical scheme of the present invention is: set up one by the crystallizer device (A) of band pulse stirrer and water cooling system and another by the die-casting chamber that can carry out semi-solid processing, colored alloy liquid storage chamber, induction heater, nonferrous alloy Liquid injection room, liquid discharge hole, holding furnace device (B), induction heating device (C), quantitative pouring device (D) and ingot withdrawal device (E) connected by non-ferrous alloy pump through tunnel to die casting room and alloy liquid storage room "A semi-solid continuous casting device for non-ferrous metals" to realize the production of high-quality non-ferrous alloy continuous casting billets, as shown in Figure 1.

The present invention is composed of crystallizer device, holding furnace device, induction heating device, quantitative pouring device, ingot pulling device and other parts. , Constant pressure tunnel, non-ferrous alloy pump, semi-solid processing die-casting chamber, control valve, high-pressure gas container, crystallizer, pulse agitator, billet drawing machine, trolley, synchronous saw.

The pouring device is connected to the injection chamber through an intrusive intersection, and the injection chamber communicates with the adjacent storage chamber at the lower part, and the storage chamber and the semi-solid processing die-casting chamber are also connected through the lower constant pressure tunnel, which is installed inside the constant pressure tunnel to drive the flow of the alloy solution The non-ferrous alloy pump is equipped with an induction heating device to control the temperature of the alloy. The welding pipe on the upper part of the semi-solid processing die-casting room is sealed and connected with the high-pressure gas container. A control valve is installed on the pipe to control the pressure of the semi-solid processing die-casting room. Semi-solid processing die-casting The outlet of the chamber is connected to the crystallizer by welding, a pulse agitator is installed outside the crystallizer, and an ingot pulling device and a billet drawing machine are installed at the outlet of the crystallizer.

One or more pulse agitators can be set, which can be pneumatic transmission or hydraulic transmission; the gas in the high-pressure gas container can be argon or other inert gas; the high-pressure gas control valve on the semi-solid processing die-casting chamber can discharge when filling liquid Gas can also be inflated when pressurized, and can also be kept under pressure; the induction heating device can be core power frequency heating.

The implementation process of the present invention is: the non-ferrous alloy melt smelted by the smelting furnace is poured into the mouth of the injection chamber through the quantitative pouring ladle, and enters the storage chamber through the lower opening of the storage chamber. Open, when the non-ferrous alloy melt entering the storage chamber reaches the specified liquid level, the non-ferrous alloy pump installed at the mouth of the constant pressure tunnel starts, and the non-ferrous alloy melt is injected into the semi-solid processing die-casting chamber and crystallizer. The control valve on the processing die-casting chamber is in the exhaust state. When the non-ferrous alloy melt entering the semi-solid processing die-casting chamber reaches the specified liquid level, the pulse agitator installed on the crystallizer is opened, and at the same time, it is set in the semi-solid processing die-casting chamber. The control valve on the top is opened, and the high-pressure gas in the container enters the upper part of the semi-solid processing die-casting chamber through the control valve and semi-solid-processes the non-ferrous alloy melt in the semi-solid processing die-casting chamber. When the pressure of the semi-solid processing die-casting chamber reaches the set value , the non-ferrous alloy melt at the front of the crystallizer has solidified, the casting machine makes a straight line drawing motion, the non-ferrous alloy ingot is slowly pulled out under the joint action of the pulling force of the drawing machine and the pressure of the high-pressure gas, and the semi-solid non-ferrous alloy casting billet After being pulled out, the synchronous saw installed on the trolley will saw off according to the set size. At the same time, the non-ferrous alloy pump continues to input the non-ferrous alloy liquid into the semi-solid processing die-casting chamber, and the quantitative pouring ladle continuously injects the non-ferrous alloy liquid into the injection chamber according to the set flow rate. Reciprocating in this way realizes the continuous production of semi-solid non-ferrous alloy casting blanks. When the continuous casting is stopped, the remaining non-ferrous alloy metal liquid in the room is discharged from the liquid discharge port.

In particular, the non-ferrous alloy pump installed at the entrance of the constant pressure tunnel can continuously inject the non-ferrous alloy melt from the non-ferrous alloy liquid storage room at normal pressure into the semi-solid die-casting chamber and crystallizer that can maintain a certain pressure, so as to realize the non-ferrous alloy in the crystallizer. The alloy melt crystallizes and solidifies after semi-solid processing. It is characterized in that the pulse agitator set on the crystallizer is always in a stirring state during the continuous production process.

The qualified non-ferrous alloy melt smelted by the melting furnace is poured into the mouth of the injection chamber through the quantitative pouring ladle, enters the storage room through the lower opening of the storage room, and enters the semi-solid processing die-casting room and crystallizer through the non-ferrous alloy pump through the constant pressure tunnel. Under the agitation of the pulse stirrer on the crystallizer, the semi-solid non-ferrous alloy is solidified into a high-quality ingot, which is pulled out and cut off by the waste machine, so that high-quality non-ferrous alloy ingot products are produced continuously and reciprocatingly.

The present invention can achieve following effect:

1. The present invention performs semi-solid processing on the non-ferrous alloy liquid in the die-casting chamber and the crystallizer, so that the traditional process of temperature control and semi-solid slurrying for the liquid metal outside the mold and the corresponding semi-solid process can be omitted. slurry and temperature control equipment.

2. The present invention performs semi-solid processing on the non-ferrous alloy liquid on the die-casting chamber and the crystallizer, so that the traditional electromagnetic stirring iron core and coil installed on the crystallizer can be omitted, and there are coils on the periphery, thereby eliminating the There are disadvantages such as peripheral magnetic flux leakage, inconvenient fixing with the shell, and high cost.

3. In the present invention, the non-ferrous alloy melt is continuously crystallized under the agitation of the semi-solid processing die-casting chamber and the pulse stirrer on the crystallizer, so the produced ingot has a dense structure and excellent product quality.

4. The present invention adopts a cored power frequency induction heating and holding furnace, which has high thermal efficiency, and overcomes the shortcoming of failure of work due to fusing of the melting channel.

5. The crystallizer of the present invention is under constant temperature and constant pressure, so the casting resistance is small and the work is stable.

6. The present invention adopts the non-ferrous alloy to pump the non-ferrous alloy liquid. Therefore, when the continuous casting is completed, the metal liquid in the casting pressure chamber and the storage chamber can be reduced to the minimum, and can be poured out from the liquid discharge hole conveniently.

7. Simple structure, easy to realize precise quantitative and automatic control.

8. It has a wide range of applications and can be widely used in various non-ferrous metals and alloys.

9. Energy saving and remarkable economic benefits.

Description of drawings

Fig. 1 is a structural representation of the present invention;

In the figure : A-crystallizer device, B-holding furnace device, C-induction heating device, D-quantitative pouring device, E-ingot drawing device;

1-Lower port of the storage chamber, 2-Drain port, 3-Injection chamber entrance, 4-Storage chamber, 5-Aeration hole, 6-Constant pressure tunnel, 7-Non-ferrous alloy pump, 8-Solid state processing die-casting chamber, 9- Control valve, 10-high pressure gas container, 11-crystallizer, 12-pulse agitator, 13-drawing machine, 14-car, 15-synchronous saw.

Detailed ways

The present invention is composed of crystallizer device, holding furnace device, induction heating device, quantitative pouring device, ingot pulling device and other parts. , Constant pressure tunnel, non-ferrous alloy pump, semi-solid processing die-casting chamber, control valve, high-pressure gas container, crystallizer, pulse agitator, billet drawing machine, trolley, synchronous saw.

The pouring device is connected to the injection chamber through an intrusive intersection, and the injection chamber communicates with the adjacent storage chamber at the lower part, and the storage chamber and the semi-solid processing die-casting chamber are also connected through the lower constant pressure tunnel, which is installed inside the constant pressure tunnel to drive the flow of the alloy solution The non-ferrous alloy pump is equipped with an induction heating device to control the temperature of the alloy. The welding pipe on the upper part of the semi-solid processing die-casting room is sealed and connected with the high-pressure gas container. A control valve is installed on the pipe to control the pressure of the semi-solid processing die-casting room. Semi-solid processing die-casting The outlet of the chamber is connected to the crystallizer by welding, a pulse agitator is installed outside the crystallizer, and an ingot pulling device and a billet drawing machine are installed at the outlet of the crystallizer.

The implementation process of the present invention is: the non-ferrous alloy melt smelted by the smelting furnace is poured into the mouth of the injection chamber through the quantitative pouring ladle, and enters the storage chamber through the lower opening of the storage chamber. Open, when the non-ferrous alloy melt entering the storage chamber reaches the specified liquid level, the non-ferrous alloy pump installed at the mouth of the constant pressure tunnel starts, and the non-ferrous alloy melt is injected into the semi-solid processing die-casting chamber and crystallizer. The control valve on the processing die-casting chamber is in the exhaust state. When the non-ferrous alloy melt entering the semi-solid processing die-casting chamber reaches the specified liquid level, the pulse agitator installed on the crystallizer is opened, and at the same time, it is set in the semi-solid processing die-casting chamber. The control valve on the top is opened, and the high-pressure gas in the container enters the upper part of the semi-solid processing die-casting chamber through the control valve and semi-solid processes the non-ferrous alloy melt in the semi-solid processing die-casting chamber. When the pressure of the semi-solid processing die-casting chamber reaches the set value , the non-ferrous alloy melt at the front of the crystallizer has solidified, the casting machine makes a straight line drawing motion, the non-ferrous alloy ingot is slowly pulled out under the joint action of the pulling force of the drawing machine and the pressure of the high-pressure gas, and the semi-solid non-ferrous alloy casting billet After being pulled out, the synchronous saw installed on the trolley will saw off according to the set size. At the same time, the non-ferrous alloy pump continues to input the non-ferrous alloy liquid into the semi-solid processing die-casting chamber, and the quantitative pouring ladle continuously injects the non-ferrous alloy liquid into the injection chamber according to the set flow rate. Reciprocating in this way realizes the continuous production of semi-solid non-ferrous alloy casting blanks. When the continuous casting is stopped, the remaining non-ferrous alloy metal liquid in the room is discharged from the liquid discharge port.

In particular, the non-ferrous alloy pump installed at the entrance of the constant pressure tunnel can continuously inject the non-ferrous alloy melt from the non-ferrous alloy liquid storage room at normal pressure into the semi-solid die-casting chamber and crystallizer that can maintain a certain pressure, so as to realize the non-ferrous alloy in the crystallizer. The alloy melt crystallizes and solidifies after semi-solid processing. It is characterized in that the pulse agitator set on the crystallizer is always in a stirring state during the continuous production process.

The qualified non-ferrous alloy melt smelted by the melting furnace is poured into the mouth of the injection chamber through the quantitative pouring ladle, enters the storage room through the lower opening of the storage room, and enters the semi-solid processing die-casting room and crystallizer through the non-ferrous alloy pump through the constant pressure tunnel. Under the agitation of the pulse stirrer on the crystallizer, the semi-solid non-ferrous alloy is solidified into a high-quality ingot, which is pulled out and cut off by the waste machine, so that high-quality non-ferrous alloy ingot products are produced continuously and reciprocatingly.

Claims (4)

1. A non-ferrous alloy continuous billet casting system capable of semi-solid processing, characterized in that: the system includes a crystallizer device, a holding furnace device, an induction heating device, a quantitative pouring device, and an ingot drawing device, and the specific structure includes: storage Chamber lower port, liquid discharge port, injection chamber port, storage chamber, vent hole, constant pressure tunnel, non-ferrous alloy pump, semi-solid processing die-casting chamber, control valve, high-pressure gas container, crystallizer, pulse agitator, billet drawing machine, trolley, synchronous saw; The pouring device is connected to the injection chamber through an intrusive intersection, and the injection chamber communicates with the adjacent storage chamber at the lower part, and the storage chamber and the semi-solid processing die-casting chamber are also connected through the lower constant pressure tunnel, which is installed inside the constant pressure tunnel to drive the flow of the alloy solution The non-ferrous alloy pump is equipped with an induction heating device to control the temperature of the alloy. The welding pipe on the upper part of the semi-solid processing die-casting room is sealed and connected with the high-pressure gas container. A control valve is installed on the pipe to control the pressure of the semi-solid processing die-casting room. Semi-solid processing die-casting The outlet of the chamber is connected to the crystallizer by welding, a pulse agitator is installed outside the crystallizer, and an ingot pulling device and a billet drawing machine are installed at the outlet of the crystallizer; The non-ferrous alloy melt smelted by the smelting furnace is poured into the mouth of the injection chamber through the quantitative pouring ladle, and enters the storage room through the lower opening of the storage room. When the alloy melt reaches the specified liquid level, the non-ferrous alloy pump installed at the entrance of the constant pressure tunnel starts, and the non-ferrous alloy melt is injected into the semi-solid processing die-casting chamber and crystallizer. At this time, the control valve located on the semi-solid processing die-casting chamber is at In the exhaust state, when the non-ferrous alloy melt entering the semi-solid processing die-casting chamber reaches the specified liquid level, the pulse agitator on the crystallizer is turned on, and the control valve on the semi-solid processing die-casting chamber is opened at the same time. The high-pressure gas enters the upper part of the semi-solid processing die-casting chamber through the control valve and semi-solid processes the non-ferrous alloy melt in the semi-solid processing die-casting chamber. When the pressure of the semi-solid processing die-casting chamber reaches the set value, the non-ferrous alloy at the front of the mold The melt has been solidified, and the drawing machine makes a linear drawing movement, and the non-ferrous alloy ingot is slowly pulled out under the joint action of the pulling force of the drawing machine and the high-pressure gas pressure. The synchronous saw on the top cuts off according to the set size. At the same time, the non-ferrous alloy pump continues to input the non-ferrous alloy liquid into the semi-solid processing die-casting chamber, and the quantitative pouring ladle continuously injects the non-ferrous alloy liquid into the injection chamber according to the set flow rate. Reciprocating realizes the continuous production of semi-solid non-ferrous alloy casting blanks. When the continuous casting is stopped, the remaining non-ferrous alloy metal liquid in the room is discharged from the liquid discharge port. 2. A non-ferrous alloy continuous billet casting system capable of semi-solid processing according to claim 1, characterized in that: one or more pulse agitators are driven by air pressure or hydraulic pressure. 3. A non-ferrous alloy continuous billet casting system capable of semi-solid processing according to claim 1, characterized in that the gas in the high-pressure gas container is argon or other inert gas. 4. A non-ferrous alloy continuous billet casting system capable of semi-solid processing according to claim 1, characterized in that: the induction heating device is core power frequency heating.

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