Heating source classification of vacuum smelting equipment

    Vacuum smelting equipment can be divided into non-ferrous metal vacuum smelting equipment and ferrous metal vacuum smelting equipment according to the types of metal materials to be smelted. Vacuum distillation can only be used for non-ferrous metal smelting. Vacuum electron beam smelting can be used for both non-ferrous metal smelting and ferrous metal smelting.

    According to different heating sources, vacuum smelting equipment can be divided into the following types.

    (1) Resistance heating

    Under vacuum conditions, the resistance heat generated by the heater is energized to melt the metal material, or the resistance heat generated by the resistance element heats the metal material through radiation. Vacuum electroslag furnace is the former, while vacuum heat treatment furnace is the latter.

    (2) Induction heating

    Under vacuum conditions, the metal material is put into the induction coil. When an alternating current is applied to the coil, an alternating magnetic field will be generated, and an induced current will be generated on the surface of the metal material. The flow of the induced current will generate resistance heat and heat the metal. The material melts. The vacuum smelting equipment heated by this method is called a vacuum induction furnace.

    (3) Arc heating

    Under vacuum conditions, metal materials are smelted using arc heat generated by arc discharge. Usually, the metal material to be smelted (consumable electrode) is connected to the negative electrode, and the water-cooled copper crucible is connected to the positive electrode. When the electricity is turned on, an arc discharge occurs between the two electrodes. The positive ions are hit on the negative plate and the electrons are hit on the positive plate, so the electrical energy is converted into heat. , Produce high temperature, melt the metal material. The vacuum smelting equipment heated by this method is called a vacuum electric arc furnace. Because the negative plate is the metal material to be smelted, it is also called a vacuum consumable furnace.

    (4) Electron beam heating

    Under vacuum conditions, an electron gun is used to emit a high-speed electron beam under the action of a high-voltage electric field. The focused energy of the electron beam hits the smelted metal material, converting electrical energy into heat energy, and melting the metal material. This kind of vacuum metallurgical equipment heated by electrons is called a vacuum electron beam furnace, and it is also called an electron bombardment furnace.

    (5) No heat source heating

    The molten steel smelted by the open hearth, converter, and electric arc furnace, due to the inhalation of oxygen, nitrogen, hydrogen and other gases during the production process, will form various defects in the interior and surface of the steel. In order to reduce these defects, vacuum secondary refining is usually used. Through low pressure treatment, the gas in the molten steel is removed. In this process, there is no heat source heating, and vacuum smelting can also be realized. Therefore, some people call it the vacuum treatment of molten steel.

(Huiputech)