Which type of gas is most commonly used in GTAW?

In Gas Tungsten Arc Welding (GTAW), argon is the most commonly used shielding gas. Argon is an inert gas, meaning it doesn't react with the materials being welded or with the tungsten electrode, which is crucial for producing a clean and high-quality weld. Its properties allow it to provide effective shielding around the welding arc, protecting it from atmospheric contamination, which can lead to defects in the weld.

The use of argon is preferred due to its excellent arc stability and ability to create a smooth, stable arc, which is vital when working with thin materials and delicate welds. Additionally, argon can efficiently cool the tungsten electrode, prolonging its life and improving the overall welding process.

While other gases like helium and carbon dioxide can be used in certain applications or for specific materials, they do not generally offer the same level of control and quality that argon provides, particularly in GTAW processes. Helium, for example, can provide higher heat input and is sometimes mixed with argon for specific applications but is not as commonly used as pure argon in GTAW. Carbon dioxide, on the other hand, is not suitable for GTAW as it is reactive and can lead to oxidation and other issues in weld quality.