In the context of GTAW, what does an inert gas prevent during welding?

In Gas Tungsten Arc Welding (GTAW), the use of an inert gas, such as argon or helium, plays a crucial role in maintaining the quality of the weld. The primary purpose of the inert gas is to prevent contamination of the weld pool. When welding, the weld pool is a molten area where the base metal is joined. If contaminants such as oxygen, nitrogen, or moisture were to enter this pool, they could react with the molten metal, leading to defects like porosity or weak bonding.

By providing a shielding atmosphere, the inert gas effectively excludes these contaminants, allowing for a cleaner and stronger weld. This is crucial for achieving high-quality welds, as even minor impurities can significantly affect the integrity and properties of the finished weld.