Friends who use cast aluminum doors should know that the structure of cast aluminum doors is different, so he can be divided into three types of doors, namely solid wood doors, solid doors and plywood doors, they are for people in life. With good security, do you know what issues need to be paid attention to when using cast aluminum doors? Let the editor explain to you:

1. Water gas: it comes from furnace gas, incompletely dried charge, refining agent, covering agent, modifier, incompletely dried lining, enamel and tool coating, and remains on the enamel, tool and charge. The water-containing solvent reacts with aluminum to generate: 2AL+3H2O→←AL2O3+6H to generate hydrogen, which enters the aluminum liquid in an atomic state.

2. The oil comes from loading and greased tools. The oil reacts with aluminum to form hydrogen.

The furnace material contains aqueous corrosives.

To reduce the absorption of gas by the aluminum alloy liquid, reasonable raw materials should be properly stored to prevent moisture. It should be fully preheated and dried before use; the smelting crucible and tools should be fully preheated to remove water vapor before use. In order to remove gas from the aluminum alloy liquid, all aluminum alloy liquid must be degassed before pouring.

3 Nitrogen purification method (also known as inert gas degassing method)

Basic principle: Nitrogen is introduced into the bottom of the molten aluminum through a certain process device. When the nitrogen floats upward from the bottom of the molten aluminum in the form of bubbles, the partial pressure of hydrogen at the interface is different. The partial pressure of the bubbles and the molten aluminum, as well as the hydrogen inside the bubbles, is very low. As the hydrogen partial pressure approaches equilibrium, the hydrogen in the alloy liquid continuously enters the bubbles. When the bubble rises to the liquid level, the hydrogen then escapes into the atmosphere and the bubble rises. In this process, the oxidized slag and its fixed impurities are simultaneously adsorbed and floated to the surface of the liquid together. The inert gas should be condensed and dehydrated before use to prevent moisture from entering the aluminum liquid. The refined quality is good, and the pores are inevitably small.

4 Mold temperature

In order to obtain high-quality castings with stable quality, the mold temperature must be strictly controlled within the optimal process range. It is necessary to apply mold cooling and heating device to ensure that the mold works in a constant temperature range, aluminum alloy: 200-260°C.

In addition to these issues, there are many things that need your attention!