What is the primary purpose of the inert gas in TIG welding stainless?

The primary purpose of the inert gas, typically argon or helium, in TIG welding stainless steel is to protect the weld puddle from atmospheric air. This is crucial because stainless steel can readily oxidize when exposed to oxygen, nitrogen, or moisture in the air during the welding process. The inert gas creates a shielding atmosphere around the weld area, which prevents contamination and oxidation, resulting in a cleaner and stronger weld.

By ensuring that the weld puddle remains free from these atmospheric elements, the inert gas helps maintain the integrity and properties of the stainless steel, such as its corrosion resistance. This protective environment is essential for producing high-quality welds that meet the demanding requirements often associated with stainless steel applications.