After the die-casting aluminum alloy is melted and refined, the aluminum water is taken from the subcontract during the subcontracting and degassing, the time before and after the refining agent is added, the nitrogen flow of the rotating degassing aluminum, the speed of the graphite rotor, the degassing time, the diameter and height of the graphite rotor. The density of molten aluminum is measured and analyzed during the production process.
After degassing, the degassing effect of different positions of the aluminum liquid in the subcontract is inconsistent, and the position near the turntable is the worst.
Nitrogen flow has a certain impact on the bubble generation location, large flow bubbles spread farther, but cause aluminum liquid toss more heavily, which will cause production safety hazards.
The rotation speed has a great influence on the degassing effect of the molten aluminum. A high rotation speed can ensure more sufficient gas diffusion and ensure that the molten aluminum does not roll.
The putting time of the refining agent has little effect on the rotating degassing aluminum, and it cannot achieve the purpose of refining the inside of the molten aluminum. The surface scum on the molten aluminum can be treated. It is recommended to use a slag remover to treat the surface aluminum slag. According to the refining agent specification, the use temperature of the refining agent is 700-750℃, and the use temperature of the slag removal and degassing agent is ≥680℃. Not easy to control.
Rotation speed and nitrogen flow must be used in conjunction to ensure the degassing effect and the molten aluminum will not roll and be oxidized. The flow rate of 15L/min at 400r/min can meet the requirements.
During the degassing process, the tumbling of the molten aluminum and the splashing of the molten aluminum affect the degassing and oxidation of the molten aluminum. After degassing, the aluminum slag on the surface of the molten aluminum and the sample density can reflect the degassing effect of the molten aluminum.