After the molten aluminium filling for a certain period of time, it starts to enter the casting stage. At this stage, the casting speed starts to rise from the initial speed to the normal casting speed, the casting temperature also starts to rise to the normal casting temperature, and the cooling water volume rises from the initial water volume to the normal casting water volume.
Pay attention to the following items during the molten aluminium casting stage:
This stage is the most prone to failure in casting, and it is prone to explosions and burns. According to relevant statistics, more than 70% of accidents in casting occurred at this stage. Therefore, special attention should be paid to safety at this stage, and the on-site personnel should be minimized.
The initial casting speed is generally 50% to 70% of the normal casting speed. Generally, the normal casting speed should be reached within the casting length of 200 mm.
The cooling water volume generally starts to rise from the initial water volume when the holding time begins. When the casting speed reaches normal, the water volume (water pressure) also reaches the normal casting cooling water volume.
Pay attention to observation at this stage, and the mold with aluminum leakage should be blocked with refractory fiber cone in time to avoid too much aluminum leakage, thereby avoiding explosion or other accidents.
At this molten aluminium casting stage, it is also easy to cause aluminum plugging due to aluminum condensation in the draft tube. There are many reasons for plugging aluminum, generally due to the low temperature of the molten aluminum or the too long filling and holding time. Specific analysis is required in actual production. The aluminum of the plug may remelt and leak during the casting process, causing an explosion. The aluminum of the plug may also cause the flow rate of the molten aluminum to be too low at a certain platform position, which makes it difficult to fill the molten aluminum and ultimately difficult to cast.
Generally, when the leaking pot or the aluminum plug reaches more than 5 crystallizers, the casting should be terminated in time to avoid danger.
At this stage, the liquid level of the casting platform will change greatly. Try to avoid large molten aluminum rolls. Pay attention to the tilting rate of the static furnace or the adjustment of the manual furnace eye. Make the platform liquid level reach a stable value in a short time. The general stability value should be 30 mm-40 mm lower than the highest surface of the platform.