What active gas is commonly used in GMAW due to its low cost, despite producing a violent arc?

The choice of carbon dioxide as an active gas in Gas Metal Arc Welding (GMAW) is attributed to its cost-effectiveness and widespread availability, which makes it a popular choice in industrial applications. While carbon dioxide can produce a more aggressive and violent arc compared to other gases, this characteristic can also lead to deeper penetration and faster welding speeds, making it desirable for certain welding tasks. Additionally, its use helps in the production of a fine, dense weld bead, which can improve the overall quality of the weld in certain materials.

In contrast, while both helium and argon are noble gases used in GMAW, they tend to be more expensive and may not provide the same penetration characteristics as carbon dioxide. Nitrogen is also less common in GMAW processes and is typically not used as a primary shielding gas due to its reactive nature, which can lead to weld defects.