A common shielding gas when performing GMAW is what?

In Gas Metal Arc Welding (GMAW), the use of shielding gas is crucial for protecting the weld pool from contamination, ensuring a clean and strong weld. The combination of Argon and Carbon Dioxide (CO2) is frequently used because it provides favorable characteristics for a range of materials, particularly mild steel.

Argon serves several purposes: it is an inert gas that helps stabilize the arc and produces a smooth, well-controlled weld bead. When mixed with a small percentage of CO2, it enhances the overall arc stability and provides a deeper penetration, which is beneficial when working with thicker materials. This mixture also helps reduce spatter compared to using pure CO2 alone, while still allowing for good wetting and fusion properties of the weld.

Using pure argon is more common for welding non-ferrous metals or stainless steel. Pure CO2, while it can work for mild steel, is more prone to spatter and less controllable when it comes to arc dynamics. Therefore, the Argon/CO2 mix is often seen as the most versatile and effective shielding gas option for GMAW, especially in fabrication and repair work where quality is a priority.