Aluminum alloy smelting has the characteristics of heat consumption, easy oxidation, easy inspiration, easy absorption of impurities metal.
1) Burning More Calories:
Although the melting point of aluminum is low, the potential heat of melting is large, the specific heat is large, the blackness is small, the [SCALE STEEL]reflection of heat is strong, and other commonly used metals such as iron, copper, when melting heat consumption.
2) Easily Oxidation:
Aluminum has a great affinity for oxygen and it can oxidize very quickly to form Al2O3. Although the alumina film formed on the melt surface has a protective effect, it is difficult to remove the oxide film once it is damaged and enters [SCALE STEEL]the melt. Because one Al2O3 is not easy to reduce, the second is its density and melt similar. It is suspended in the melt, with the melt into the ingot, to the quality of processing materials will be adversely affected. What's more, aluminum oxide is a good carrier of various gases, and its presence will make aluminum melt absorb a lot of hydrogen. Therefore, reducing oxidation as much as possible is an important problem in aluminum alloy smelting.
3) Easy to Inhale:
Aluminum and aluminum alloys have a strong ability to inhale (mainly hydrogen), especially in the presence of water vapor or reducing atmosphere in the furnace gas. Although the absolute amount of hydrogen absorption of aluminum [SCALE STEEL]and aluminum alloy is not large, but at the melting point, the solubility of hydrogen in the solid phase and the liquid phase is very different, the formation of porosity and porosity of the ingot crystallization tendency is very large. Therefore, reducing hydrogen absorption as much as possible is another important problem in aluminum and aluminum alloy smelting.
4) Easy to Absorb Metal Impurities:
Some of the alloyed elements in aluminium and aluminium alloys are highly chemically active. They not only absorb iron dissolved directly from iron crucible and tools, but also replace iron, silicon, zinc and other metallic impurities [SCALE STEEL]from many oxides in furnace lining and many chlorine salts in fluxes. Once these metallic impurities enter the aluminum melt, they cannot be removed. And the more times of melting, the higher the impurity content, the greater the impact on the performance of the alloy, the serious grade degradation of pure aluminum, the alloy composition exceeds the standard and scrapped. [SCALE STEEL]Therefore, to prevent the pollution of metal impurities is the third important problem in the smelting of aluminum and aluminum alloy.
FROM SCALE STEEL