In the aluminum coil rolled products industry, the continuous casting and rolling process have been widely used in the production of coils.
In the world’s total output of aluminum plates, strips, and foils, hot-rolled billets are less than 20%, and lower-cost twin-roll continuous casting billets are more than 80%.
Improving the quality of double-roll continuous cast-rolled aluminum coils can eliminate defects such as white strips, black spots, large grains, sticky rolls, and cracked edges of the cast-rolled sheet.
The characteristic of the twin-roll aluminum coil continuous casting-rolling process technology is continuous uninterrupted production. Any accident or frequent start and stop caused by power outages will cause the quality of the cast-rolled plate to fluctuate. Therefore, it is very important to maintain the long-term stable operation of the twin-roll continuous casting-rolling machine.
It is necessary to strengthen the degassing and filtration of molten aluminum, add grain refiners, and at the same time strengthen the sense of responsibility of the operators.
The method of purifying molten aluminum in the furnace can only remove the newly added impurities during the melting process, but cannot eliminate the secondary pollution of the molten aluminum during the pouring process. At the same time, due to the large area of the furnace and the shallow depth of the molten pool, flux refining is difficult to effectively purify molten aluminum in every corner.
Therefore, in the modern melting and casting process, the online degassing and filtering purification treatment method outside the furnace is used, it makes the aluminum liquid contact with the gas flux in the degassing filter box, and then flow into the semi-continuous casting mold or the continuous casting tip and nozzle. This ensures that all molten aluminum is effectively purified and prevents secondary pollution.
After online degassing and filtering purification treatment, the hydrogen content of molten aluminum can be reduced by 60%. Non-metallic inclusions with particle diameters below 50 um can be removed by 50%, and those above 100 um can be removed by 90%.