All need to charge preheating before entering furnace, to remove the surface of the water, shorten the melting time.
2. Crucible and melting tool preparation
(1) new crucible before use should be clean and carefully check without penetrating defect, confirmed the absence of any defects can be put into use, preheating to dark red (500 - 600 degrees) insulation for more than 2 hours, to burn except attachment in the crucible wall of water and the combustible matter, be cooled to below 300 degrees, carefully clean the inner wall of the crucible, at a temperature of not less than 200 degrees, spray paint brush, dry after appearing to use.
(2) Press spoon, mixing spoon, ladle melting tool before use must be as residual metal and oxide skin and dirt removal. After 200-300 degrees preheating after coating with protective coating, brushing after drying stand-by.
3. Melting temperature control
Alloy liquid quickly rose to high temperature (705 degrees), reasonable stirring, in order to promote the dissolution of all alloy elements, confirming that all elements are dissolved, in addition to gas, in addition to the expense of dross is approaching the pouring temperature refining. (for aluminum solution temperature is difficult with the naked eye to judge, so must be used to control the temperature of instrument for temperature measurement, temperature measurement instrument should be regular calibration and maintenance; thermowell should cycle with the metal brush clean, Tu to protective coating, to ensure the accuracy of the measurement results and prolong the service life.
4. Melting time control
In order to reduce the oxidation of aluminum solution, air suction, the residence time in the furnace can be shortened, and the rapid melting of aluminum solution can be reduced. In order to speed up the melting process should be first join the secondary fragmentation, low melting of recycled material, so that in the bottom of the crucible as soon as possible the formation of molten pool, then add out of aluminum ingots, which can slowly immersed gradually expanded molten pool and accelerate melting; after the main burden partially melted, then add with high melting point, number of alloy elements, heating, stirring so as to accelerate melting, finally cooling,, easily pressed into the oxidation of alloy elements.
