What is the main purpose of shielding gas in Metal Arc Gas Shielded Welding?

The main purpose of shielding gas in Metal Arc Gas Shielded Welding, often referred to as Gas Metal Arc Welding (GMAW), is to prevent oxidation. During the welding process, the high temperatures can cause the molten metal to react with oxygen and other atmospheric gases. This reaction can lead to defects in the weld, such as porosity and weakened joints.

By using a shielding gas, which is typically an inert gas like argon or a mixture of gases, the atmosphere around the weld pool is protected from these harmful reactions. The shielding gas creates a protective barrier that displaces oxygen and moisture, allowing the molten metal to solidify without contamination. This contributes significantly to the integrity and quality of the weld, ensuring better performance in the final product.

While other options may have their own roles in different welding processes, they do not align with the primary function of shielding gas in this specific context.