Continuous casting and rolling for aluminum sheet is a process in which liquid aluminum crystallizes in a twin strip caster. In terms of production cost, energy saving and consumption reduction, cast rolling method and continuous casting and rolling method have advantages over traditional ingot rolling method. However, the export thickness of cast rolling products is much thicker than that of continuous casting and rolling method, so the subsequent cold rolling passes need to be increased; and the cast rolling slab is mostly as-cast structure, which is unfavorable for subsequent processing.
The continuous casting and rolling process for aluminum sheet, like the casting rolling method, saves the energy consumption of aluminum ingot cutting, milling surface and aluminum ingot preheating in the traditional aluminum ingot rolling method, and the lower limit of hot rolling strip thickness of continuous casting and rolling is only 1 mm, which is much thinner than that of traditional aluminum ingot rolling method, and can save most cold rolling passes. In the process of continuous casting and rolling for aluminum sheet, hot top accessories such as flow control box, Ladle Shroud, casting launder, caster tip and nozzle, which can control the flow rate of molten aluminum very well.
The continuous caster has a high cooling rate, which makes it easy to obtain smaller grain size. The crystal structure of the strip is compact and fine, the dendrite spacing is small, and the solid solubility of alloy elements is large, so the product performance is improved to a certain extent. Compared with cast rolling method, continuous casting and rolling method can meet the requirements of producing alloy varieties with wider crystallization range.
In order to improve the effect of purification treatment and ensure the stability and reliability of melt quality, continuous purification treatment in the furnace and outside furnace is adopted. The main functions of the on-line refining equipment are to refine grain size, strengthen degassing refining, remove slag, and alkali metal impurities. Online degassing and filtering devices include: degassing unit, electrical control cabinet, gas control cabinet, immersion heater, rotary nozzle, lifting device, filter box, filter plate, and heating device, etc.