Welding gas is an essential component of the welding process. It plays a critical role in providing a safe and consistent welding environment. The main purpose of a welding gas is to shield the weld zone from the atmosphere and protect the weld pool from oxidation and contamination. In this article, we will discuss the commonly used welding gas and their applications.
Argon
Argon is one of the most popular and commonly used welding gases. It is a non-reactive, inert gas that is composed of 79% argon, 21% nitrogen, and small amounts of oxygen, carbon dioxide, and other trace gases. Argon is used with many types of welding processes, and it is the most common shielding gas for TIG (tungsten inert gas) and plasma arc welding. This is because its low reactivity prevents contamination of the welding arc, which results in a better weld quality.
Helium
Helium is an inert, non-reactive gas that is composed of 99.997% Helium and 0.003% Nitrogen. Helium is most commonly used in welding processes where higher welding speeds are necessary to improve productivity. The higher thermal conductivity of Helium allows for faster heating rates and higher welding speeds, which ultimately lead to a higher welding quality. In addition, Helium provides better protection from the atmosphere, which reduces oxidation and the risk of contamination during welding.
Carbon Dioxide
Carbon Dioxide (CO2) is a reactive gas that is composed of one Carbon atom and two Oxygen atoms. It is the most commonly used shielding gas for MIG (metal inert gas) welding. CO2 is highly reactive and helps in controlling the heat and creating an arc that is stable and deep enough to produce high quality welds. Its higher reactivity also promotes faster cooling, which helps reduce the risk of weld defects and distortion.
Mix Gases
When using a gas mixture, two or more gases are mixed together to form a unique shielding gas. Gas mixtures are often used to improve weld characteristics and optimize the performance of the gas. Mix gases are commonly used in TIG welding and MIG welding and they can help provide a higher quality weld and better metal penetration.
Conclusion
Welding gas is essential in providing a safe and productive welding environment. The type of shielding gas used will depend on the type of welding process and the chemistry of the base metal. Arron, helium, and CO2 are the most commonly used shielding gases and can be used with many different welding processes. Mix gases are also available to provide more control over the welding characteristics.
