What gases can be passed through a vacuum tube furnace?

There are various types of gases that can be introduced into a vacuum tube furnace, depending on the needs of the experiment or production. Here are some common gases that can be introduced into a vacuum tube furnace:

Inert gas:
Nitrogen (N ₂): commonly used to protect the surface of heat-treated parts from oxidation, and can also be used in conjunction with other ventilation gases to improve the heat treatment effect.
Argon (Ar): As an inert gas, it is commonly used to provide inert gas environmental protection and prevent oxidation or contamination of heat-treated parts at high temperatures.
Helium (He): Used in certain special situations, such as heat treatment under high vacuum conditions.
Reductive gas:
Hydrogen (H ₂): Used to accelerate heating processes, improve heat treatment efficiency, and is particularly suitable for processes that require a reducing atmosphere.
Oxidative gas:
Oxygen (O ₂): Provides oxygen supply agent in certain processes, promotes combustion process, accelerates heating speed, and improves process efficiency. Meanwhile, it can also promote redox reactions, which is beneficial for improving the heat treatment effect.
Other gases:
Carbon dioxide (CO ₂): used as a reactive gas or protective atmosphere in certain specific processes.
Water vapor (H ₂ O): participates in chemical reactions as a reactive gas in certain processes.
Ammonia decomposition gas: Hydrogen and nitrogen are produced through the decomposition of ammonia gas, which is used in processes that require a mixed atmosphere.
Hydrocarbons (such as methane, ethane, etc.): used as carbon sources in certain carburizing processes.
In addition, according to specific heat treatment processes and experimental requirements, other types of gases or mixed gases can also be introduced. The ventilation system of a vacuum tube furnace is usually designed with inlet and outlet ports, which can control the flow rate and pressure of gas through valves to meet different process requirements.

It should be noted that before introducing gas, the sealing of the vacuum tube furnace should be ensured to prevent gas leakage. At the same time, appropriate gas types and flow rates should be selected based on the specific requirements of the experiment or production to ensure the stability of the process and the quality of the product.