What is the primary shielding gas used in gas tungsten arc welding?

What is the primary shielding gas used in gas tungsten arc welding?

• A. Oxygen
• B. Argon
• C. Helium
• D. Carbon dioxide

Answer: (B)

The primary shielding gas used in gas tungsten arc welding (GTAW) is argon. Argon is favored in this process because it is an inert gas, meaning it does not react with the molten metal being welded. This property is crucial as it protects the weld puddle from atmospheric contamination, which can lead to defects in the weld such as oxidation or porosity. Argon provides a stable arc and is effective in preventing oxidation in a variety of metals, making it suitable for welding materials like aluminum and stainless steel, where clean and high-quality welds are essential. Helium, while also a shielding gas, is typically used in less common applications or when larger penetration is required, but argon remains the most widely used gas in GTAW due to its effectiveness and lower cost. The other gases listed are either reactive or not suitable for the GTAW process, thereby making argon the standout choice for this application.

The primary shielding gas used in gas tungsten arc welding (GTAW) is argon. Argon is favored in this process because it is an inert gas, meaning it does not react with the molten metal being welded. This property is crucial as it protects the weld puddle from atmospheric contamination, which can lead to defects in the weld such as oxidation or porosity.

Argon provides a stable arc and is effective in preventing oxidation in a variety of metals, making it suitable for welding materials like aluminum and stainless steel, where clean and high-quality welds are essential. Helium, while also a shielding gas, is typically used in less common applications or when larger penetration is required, but argon remains the most widely used gas in GTAW due to its effectiveness and lower cost. The other gases listed are either reactive or not suitable for the GTAW process, thereby making argon the standout choice for this application.