Which statement is not an advantage of argon vs helium as a shielding gas in GTAW?

Which statement is not an advantage of argon vs helium as a shielding gas in GTAW?

• A. Argon yields smaller heat-affected zone
• B. Helium provides deeper penetration
• C. Argon is less expensive
• D. Argon provides good arc stability

Answer: (A)

Shielding gas choice changes how hot and stable the GTAW arc is, which in turn affects how the weld bead forms and how much heat gets into the base metal. Helium makes a hotter arc with deeper penetration, but this comes with more heat to the workpiece. Argon, on the other hand, generally gives a steadier arc and is cheaper to use, with heat input that’s easier to manage for many jobs. The heat-affected zone size isn’t guaranteed to be smaller just because argon is used; it depends a lot on welding current, travel speed, and material, so saying argon yields a smaller HAZ isn’t a reliable, universal advantage. That’s why that statement isn’t considered an advantage of argon over helium.

Shielding gas choice changes how hot and stable the GTAW arc is, which in turn affects how the weld bead forms and how much heat gets into the base metal. Helium makes a hotter arc with deeper penetration, but this comes with more heat to the workpiece. Argon, on the other hand, generally gives a steadier arc and is cheaper to use, with heat input that’s easier to manage for many jobs. The heat-affected zone size isn’t guaranteed to be smaller just because argon is used; it depends a lot on welding current, travel speed, and material, so saying argon yields a smaller HAZ isn’t a reliable, universal advantage. That’s why that statement isn’t considered an advantage of argon over helium.