What is the primary benefit of using CO2 as a shielding gas in GMAW?

The primary benefit of using CO2 as a shielding gas in Gas Metal Arc Welding (GMAW) lies in its ability to provide better penetration compared to other gases. When CO2 is used, it creates a hotter arc during the welding process, which enhances the melting of the base material. This results in deeper and more effective penetration, making it well-suited for welding thicker materials and improving the weld quality.

While CO2 is indeed more economical than other shielding gases, especially argon or a mixture of argon and CO2, the key reason it is widely favored in many applications is due to the improved penetration it provides. This characteristic is crucial in various welding scenarios where a strong joint is necessary. Additionally, CO2 can reduce spatter and improve arc stability to some extent, but these are supportive benefits rather than the primary reason for its use.