What is the main gas used for MIG welding?

The main gas used for MIG (Metal Inert Gas) welding is indeed Carbon Dioxide (CO2). This gas plays a crucial role in the MIG welding process as it is employed to protect the molten weld pool from atmospheric contaminants, helping to create a stable arc and improve the overall quality of the weld. CO2 is commonly used because it is cost-effective and provides good penetration when welding thicker materials.

While other gases like Argon and Helium are also utilized in MIG welding, especially in combination with CO2 for specific applications, CO2 is the most frequently used shielding gas in standard MIG processes. Argon is often blended with CO2 to enhance weld quality for certain materials, and Helium is primarily used in welding applications that require higher heat input, but it is not the main gas in typical MIG welding operations. Oxygen is generally not used in MIG welding as it can lead to oxidation of the weld and negate the protective benefits that the shielding gas is intended to provide.