Common sense of magnesium alloy smelters
Magnesium alloy melting is done in specialized furnaces that can be heated with wires, oil or gas, according to magnesium alloy smelters. Gas heaters are widely used in the United States because of the low cost of gas. But because the scale on the gas heating furnace will lead to the crucible wear, the formation of water vapor, so a lot of use of electric furnace. In Europe, electric heaters are dominant. The electric heating furnace is simple to operate and can accurately control the temperature. The thermocouple is installed inside the furnace, near the heating element, to prevent overheating.
For magnesium alloy hot chamber die casting machine, hot parts such as pot and punch ring are also very important. The die casting temperature of magnesium alloy in hot chamber is generally 630~650, much higher than that of zinc alloy. The hot parts working in high temperature magnesium alloy liquid should not only have good high temperature strength, but also have corrosion resistance of magnesium alloy liquid. Because the working conditions are very bad, there are special requirements for the materials used. Magnesium alloys have active chemical properties, which can corrode hot working materials and be corroded by protective gases in production. In addition, it has high working temperature and fast injection speed, which requires higher high temperature performance of hot working materials. The study of hot working materials in die cast magnesium alloy furnace has become one of the important factors affecting the development of die cast magnesium alloy.
Magnesium alloy smelters say the ingot must be preheated to more than 150 before being added to the smelter to remove moisture from the ingot and avoid the risk of explosion when added to the smelter. Preheating the ingot before subsequent addition can also avoid large fluctuations in the temperature of the liquid magnesium and improve the melting efficiency of the furnace. Therefore, the magnesium alloy melting furnace should be equipped with an automatic preheating device of the holding furnace type, and can also be connected with an automatic feeding device to automatically add the preheated magnesium ingot to the melting furnace.
Magnesium alloy smelting furnace manufacturers say that with the rapid development of magnesium alloy die casting at home and abroad, magnesium alloy melting quantitative furnace is paid more and more attention. Our magnesium alloy melting pot has experienced the transition from using covering agent to introducing advanced gas protection quantitative furnaces. Imported melting furnace is expensive, maintenance spare parts have a certain period, the cost is high. The rapid development of magnesium alloy die casting industry has promoted the technological update of melting furnace. At present, domestic manufacturers have produced gas protected magnesium melting quantitative furnace, but the reliability needs to be improved. Therefore, it is an important task for magnesium alloy industry to develop a reliable, safe and suitable quantitative melting furnace for our country.
Magnesium alloy continuous ingot casting machine manufacturers said that, at present, lead ingot casting equipment has been widely used in domestic lead smelters, the main operation has achieved varying degrees of mechanization or automation, casting, the use of lead pump molten lead pot liquid lead pump into the casting bag, liquid lead through the casting bag quantitative pouring device injected into the ingot mold for casting, scraper liquid lead ingot surface slag layer, Then, after cooling forming, printing and demudding process, the demudding lead ingot is stacked by cantilever hanging. It plays an active role in improving the working conditions and reducing the labor intensity of finished lead ingot.
The core of magnesium alloy continuous ingot casting machine is continuous casting technology. Continuous casting is a casting method in which liquid metal is continuously injected into one end of the die and molding materials are continuously pulled out from the other end. When the casting is drawn from the metal form to a certain length, the casting can be cut off while pouring; It is also possible to stop pouring when the casting reaches a certain length in order to obtain a certain length of casting. Magnesium alloy continuous ingot casting machine can be used for casting various high density plate, round bar, hollow pipe and other profiles.
Magnesium alloy smelters say that magnesium alloys are very active among all metals because they have an ignition point of 550℃ and a melting point of 650℃. At high temperatures, it reacts with oxygen to form magnesium oxide, while it reacts with water to form hydrogen and magnesium oxide, which causes an explosion. Therefore, metal oxidation or combustion must be prevented effectively in the process of melting magnesium alloy, which is usually achieved in the process of flux or no flux on the surface of metal melt. A large number of experimental studies show that gases such as C02.S02.SF6 can play a good protective role on magnesium and its alloy melt, but these substances will react with magnesium to form other substances. Such substances constitute impurities in magnesium soup, and a large number of impurities will float on the surface of the molten soup or adhere to the furnace side wall, and the dense ones will sink to the bottom of the furnace. When the substance becomes thicker and more concentrated, a large amount of this substance adheres to the crucible wall of the furnace. After a period of time, it will form a hard solid layer of material, causing a decrease in the volume of crucible. At the same time, heat from the external heating device of crucible cannot be properly transmitted into crucible, which reduces the melting speed and cannot meet the production requirements, thus reducing the production efficiency of die casting and seriously affecting the service life and product quality of crucible.
The shell of magnesium alloy furnace is made of high quality steel plate and high quality insulation material. The furnace has advanced structure, low energy consumption and fast melting speed. The design of double chamber crucible is reasonable and can be used in two die casting machines at the same time. High quality imported radiation processing thermal components, long service life, high thermal efficiency.
What are the advantages of magnesium alloy smelters? Let's find out.
In magnesium alloy smelting process, metal oxidation reaction should be avoided to prevent metal combustion. To achieve this effect, we usually sprinkle some flux on the metal melt. Sometimes, we can also use fluxless processes. The common flux is beryllium metal, and the common flux free process is flux free melting. The melting process of magnesium alloy is mainly flux melting. The flux removes impurities from the magnesium and forms a protective film on the surface of the magnesium alloy melt to isolate air. However, the effect of flux film on air isolation is not very ideal, and the magnesium loss caused by oxidation combustion in smelting process is relatively large.