The nozzle for aluminum roll casting provides the casting and rolling zone with a uniform, stable and continuous molten aluminum in the width direction of the plate, which is a prerequisite for the smooth progress of rapid ultra-thin continuous casting and rolling. The existing casting and rolling machines have different casting nozzle structures, and the flow state of the caster nozzles during production is a major problem that restricts normal production. The problem of poor casting nozzle flow leads to strip shape defects, which will affect the subsequent cold rolling process and cannot produce high-quality strip products stably and efficiently.
During the fast ultra-thin casting, due to the reduction of the roll gap of the casting roll and the increase of the speed, the flow state of the aluminum melt in the casting nozzle is more complicated, and the flow resistance and flow velocity distribution will change greatly. The corresponding change in the flow heat loss of the aluminum melt causes the temperature distribution of the molten aluminum to also change, which makes the distribution problem more prominent. Therefore, how to solve the problem of flow distribution in the nozzle cavity is the key to achieving fast ultra-thin casting and rolling and obtaining high-quality cast slabs.
The nozzle for aluminum roll casting has a small gap and a large fluid resistance, which can improve the flow of the melt. However, it is precisely because of the small gap between the runners that the viscosity of the melt changes with the ambient temperature affects the balance of the melt flowing through these gaps, and the unreasonable split gap directly leads to local blockage and affects the quality of the cast slab. Therefore, the size and clearance of some flow blocks in the casting nozzle are strictly required, and the manufacturing process is complicated.