Vacuum metallurgy melting equipment. Furnace for airtight containers, pumping into a vacuum or filled with inert gas. The electrode and the bottom water-cooled crystallizer, which are led in from the top of the furnace, are energized and arc-generated, the metal or alloy is melted by the heat of the arc and solidified in the crystallizer. The electrodes are made of molten metal called "consumable electrode vacuum arc furnace", such as using non-melting material for the electrode called "non-consumable electrode vacuum arc furnace." Products less impurities, low gas content, good ingot structure, with excellent mechanical and physical properties. Suitable for melting high melting point metals, active metals, special steels and metals.
Arc is an arc discharge of gas. Gas arc discharge showed very low voltage between the electrodes, but the current through the gas is large, bright white light, the arc zone temperature is high (about 5000k). The huge current density comes from the cathode's hot electron emission and the electron's self-emission, that is, there is a positive ion layer near the cathode to form a strong electric field so that the cathode emits electrons automatically. A large number of electrons collide with gaseous molecules in the ionization chamber to ionize them, resulting in a larger amount of positive ions and secondary electrons, which collide with the cathode and the anode respectively under the effect of an electric field. As a result, high temperatures are obtained. Cathode due to the electron emission to use part of the energy, so the temperature is lower than the anode. Extremely due to some positive ions and electrons combined heat generated high temperature.
Electric arc furnace is the principle of using this principle smelting metal furnace. In the vacuum environment of the electric arc furnace is a vacuum electric arc furnace, vacuum arc melting with high current and low voltage, are short arc operation. General arc voltage is 22 ~ 65V, the corresponding arc length of 20 ~ 50mm (the latter for the ingot). From the successful experiment of melting white gold wire in 1839, more than one hundred years later people began to study the smelting of refractory metal. 1953 vacuum electric furnace was officially used in industry. Until 1956, many countries in the United States and Europe still smelted titanium with non-consumable furnaces, and steelmaking began with consumable furnaces in 1955. In 1960 about the consumption of furnace production of ingot has reached more than 30 tons, beginning to take shape. The current development of the situation can be used in the United States made by the company Saussac vacuum consumable furnace as the representative. In order to increase productivity and equipment utilization, two stoves share a main power supply, vacuum system and automatic control system.
In the vacuum state of the workpiece (or material) for heat treatment, can improve the service life of mold, mold, no oxidation, no decarburization, surface brightness, small deformation, energy saving and pollution-free, and change the mechanical properties and metallurgical properties and so on.