Views: 13 Author: Site Editor Publish Time: 2021-08-06 Origin: Site
Gas arc discharge is characterized by low voltage between electrodes, large current through the gas, bright white light, high arc temperature (about 5000K). The huge current density comes from the hot electron emission of the cathode and the self-emission of the electron, that is, there is a positive ion layer near the cathode, resulting in a strong electric field that causes the cathode to actively emit electrons.
Lots of electrons bump into the gas molecules at the electrode, ionizing them, and then lots of positive ions and subelectrons occur. Under the effect of electric field, they collide with the cathode and anode separately, resulting in high temperature. Because some of the energy is used for electron emission, the temperature of the cathode is lower than that of the anode. High temperatures can also occur between the poles due to the combined heat release of some positive ions and electrons. Vacuum arc furnaces are industrial furnaces that use this principle to smelt metals. Electric arc furnace under vacuum environment is a vacuum electric arc furnace. Vacuum arc furnace smelting uses high current, low voltage, due to short arc operation.
In general, the arc voltage is 22-65V and the corresponding arc length is 20-50mm (the latter being the large ingot). Since the successful melting of platinum wire in 1839, people have been studying the melting of refractory metals in the next 100 years. In 1953, vacuum electric arc furnace was officially put into industrial application. Titanium was smelted in non-consumable furnaces in the United States and much of Europe until 1956, and steel was smelted in consumable furnaces in 1955. Around 1960, the weight of steel ingot produced by self-consuming furnace reached more than 30 tons, and began to take shape.
At present, the two furnaces share a main power supply, a vacuum system and an active control system in order to improve production power and equipment utilization. Vacuum heat treatment of the workpiece (or material) can improve the service life of things and molds, no oxidation, no decarbonization, smooth surface, small deformation, energy saving, no pollution, change mechanical metallurgical properties.