Among the numerous different types of welding processes available today, Gas Tungsten Arc Welding or GTAW, is generally considered the most challenging welding method to master. Although it is more time consuming than other welding methods, even when practiced with the care of an expert, the improved strength and quality of welds produced with GTAW can offer a practical alternative to simpler welding methods, particularly for narrow sections of stainless steel and non-ferrous metals such as copper, aluminum, and magnesium alloys.
GTAW, also known as tungsten inert gas (TIG) welding, is a type of arc welding which produces the weld using a non-consumable tungsten electrode. Inert gases such as argon or helium are used to protect the area being welded from contamination and most, although not all, welding applications will require filler metal. A column of plasma, made up of highly ionized gas and metal vapors, conducts energy across the arc and is produced by a constant-current welding power supply.
Another type of GTAW is pulsed GTAW, this process uses a power source that generates the pulsed welding current which makes the average current higher for better penetration and control of the weld craters, especially for root pass welding. The main benefit of the Pulsed GTAW is for pipe welding positions on stainless and non ferrous materials such as nickel.
GTAW can also be applied for automatic welding. This process requires a power source and programmable control, a wire feed system and a motion guide machine. This process has been used to manufacture high-quality tube-to-tubesheet welds and blunt welds on heat exchanger pipes.