What is the primary source of heat in the GTAW process?

In the Gas Tungsten Arc Welding (GTAW) process, the primary source of heat is generated by an electric arc that forms between the non-consumable tungsten electrode and the workpiece. This arc produces intense heat, allowing the welder to melt the base materials at the joint being welded. The tungsten electrode is maintained at a relatively low temperature due to its high melting point, while the arc provides the necessary heat for melting the metal.

The electric arc is fundamental to the GTAW process, as it not only creates the heat required for welding but also facilitates the control over the welding process. By adjusting the arc length and the current, a welder can control the heat input and, subsequently, the penetration depth and bead shape.

Other options like a flame from a torch or pre-heated gas are not utilized in the GTAW process, which distinguishes it from other welding techniques that rely on combustion for heat. Additionally, while induction coils can be used to heat metals in other processes, they are not applicable in GTAW, where the focus is on the direct heat from the electric arc.