| Salt-bath furnace refers to immersing workpieces into salt liquid for heating by adopting molten salt liquid as heating medium. According to operating temperature of furnace, heating medium usually adopts sodium chloride,potassium chloride, barium chloride, sodium cyanide, potassium cyanide, sodium nitrate, potassium nitrate etc. Salt-bath furnace has fast heating speed and uniform temperature. Being continuously heated in salt liquid, workpiece form a layer of salt membrane on the surface after coming out from the furnace so as to prevent workpiece surface from oxidation and decarburization. Salt-bath furnaces are applicable to such heat treatment heating as quenching, annealing, tempering, nitriding and aging for carbon steel, alloy steel, tool steel, mold steel and aluminum alloy etc. as well as to less oxidation heating of steel material precision forging. Being harmful to human body, the steam of salt-bath furnace heating medium must be used under ventilated condition. Electrode salt-bath furnace leads low voltage (5.5¡«36) high current AC to the furnace through metal electrode and current flows through salt liquid to give out heat. Salt liquid is heating unit and the medium for workpiece heating as well. Salt liquid temperature ranges from 150 ¡æ to 1300 ¡æ according to salt liquid component. Magnetic action can make salt liquid turning circularly, which facilitates uniformity of salt liquid temperature and increase heating speed of workpieces. Electrode salt-bath furnace consists of electrode, fire-resistant furnace lining, insulting layer and furnace shell and is electrified by special transformer. Because of non-conductivity of solid state salt, firstly convey electricity to starting electrode in time of starting up the furnace, utilize resistance heating of starting electrode to melt partial salt, then connect main electrode to make current pass through molten salt for heating operation. |
