What is the main function of shielding gas in gas tungsten arc welding?

The primary function of shielding gas in gas tungsten arc welding (GTAW) is to protect the weld area from atmospheric contamination. When welding, particularly with materials like aluminum and stainless steel, exposure to oxygen and nitrogen in the air can lead to the formation of oxides and other contaminants that weaken the weld joint. The shielding gas, typically argon or a mixture of argon and helium, creates an inert atmosphere around the weld area, effectively blocking these harmful elements.

This protective environment allows for a cleaner and stronger weld by preventing oxidation and other atmospheric reactions that could compromise the integrity and appearance of the weld. Moreover, using the appropriate shielding gas not only safeguards the weld from contamination but can also influence other factors, including arc stability, heat input, and bead appearance, thereby enhancing the overall quality of the weld.