Which current type is seldom used for GTAW?

In the context of Gas Tungsten Arc Welding (GTAW), the choice of current type significantly influences the welding process and the characteristics of the weld. Direct Current Electrode Positive (DCEP) is seldom used in GTAW because it results in a higher concentration of heat at the workpiece compared to the tungsten electrode. This can lead to excessive wearing of the tungsten electrode and may not provide the clean, precise welds typically required in GTAW applications.

GTAW predominantly utilizes Direct Current Electrode Negative (DCEN) or Alternating Current (AC). DCEN is favored for most materials as it allows for greater heat concentration on the workpiece while minimizing tungsten wear, leading to finer control and precision in the weld. AC, on the other hand, is particularly beneficial for welding non-ferrous materials like aluminum, as it allows for the cleaning of the oxide layer from the surface of the metal.

Pulsed DC is also commonly employed for its ability to control heat input and improve the quality of welds, especially in thin materials or during out-of-position welding.

In summary, the limited use of DCEP in GTAW is due to its tendency to wear out the tungsten electrode quickly and the preference for current flows that provide optimal heat