Which type of shielding gas is commonly used in GMAW?

The use of carbon dioxide as a shielding gas in Gas Metal Arc Welding (GMAW) is significant due to its ability to provide good arc stability and penetration. Carbon dioxide is typically used because it is cost-effective and enhances the heat of the arc, which is essential for welding thicker materials. This gas can create a more concentrated arc and better weld bead characteristics, making it a popular choice among welders for various applications.

While other gases like oxygen, nitrogen, and hydrogen may be used in specific welding contexts, they are not as commonly associated with GMAW. For instance, oxygen can lead to oxidation of the weld metal, which is undesirable. Nitrogen is typically not utilized as a shielding gas in welding due to its inert qualities. Hydrogen may be used in certain situations but generally in conjunction with other gases rather than as a primary shielding gas in GMAW. Therefore, carbon dioxide stands out as the primary choice owing to its advantages in creating strong welds and maintaining arc quality.