gasTIG

gasTIG refers to a variant of gas tungsten arc welding (GTAW or TIG) in which a secondary gas flow is introduced near the arc and weld pool. The aim is to alter the shielding environment and arc characteristics to improve weld quality. It is used by some practitioners and suppliers, but it is not a standard designation in major welding codes or norms.

In gasTIG, the torch still delivers the conventional shielding gas, typically argon, helium, or a mixture. A secondary gas is supplied through a separate line or coaxial nozzle and directed at the arc or weld pool. Common secondary gases include hydrogen or nitrogen, used in specific alloys and welding regimes. The secondary flow can influence arc stability, heat input, and penetration, with the goal of achieving better bead shape and reduced oxidation on certain metals.

Implementation requires compatible hardware: a TIG power source, a dual-gas delivery system with flow controls, and suitable nozzles or adapters. Operators tune the main shielding gas flow, secondary gas flow, current, and travel speed to balance weld quality, porosity, and heat input. Adequate ventilation and safety precautions are important when hydrogen-containing mixtures are employed.

Applications cited for gasTIG include thin-section welding and challenging alloys such as aluminum, titanium, and stainless steel, where conventional GTAW may exhibit oxidation or instability. Reported advantages include improved arc stability and surface integrity in some cases, while drawbacks include higher gas consumption, added hardware complexity, and the need for careful parameter optimization to avoid defects. The term remains largely vendor-specific and is not universally recognized as a distinct, standardized welding process.