When is helium typically used in GTAW welding?

Helium is typically used in Gas Tungsten Arc Welding (GTAW) to enhance heat input and increase welding speed. When helium is utilized as a shielding gas, it provides a higher thermal conductivity compared to argon, which allows for a more concentrated arc. This concentrated arc results in higher temperatures that facilitate faster welding, especially when working with materials that require greater heat input, such as aluminum and certain nickel alloys.

By improving the overall heat distribution in the weld area, helium also supports improved penetration and helps achieve a strong bond between the base metals. This characteristic makes it particularly beneficial in applications needing significant heat input while maintaining a faster travel speed.

While helium can be mixed with argon to optimize characteristics for specific situations, solely relying on argon would not achieve the same effects in terms of speed and heat input that helium does. Thus, the use of helium in GTAW is specifically aimed at achieving higher welding speeds and enhanced heat, making it valuable in various welding operations.