Electrode for the Tube Welder

Most tube welder equipment requires certain replaceable parts in order to operate. In most cases, that replacement part is the weld head. For the orbital tube welder, one of the most important parts is the Tungsten electrode. It is easily one of the most important elements of the welding system. Surprisingly, this is one of the aspects of the machinery that is usually ignored by the operators.

Because of this ignorance, welding efficiency and success falters. By selecting the proper Tungsten parameters, you can begin to find the proper process to create a better product. It can help to prevent arc wander and promote good weld penetration.

In the past, Tungsten manufacturers found it necessary to include oxide to pure Tungsten in order to improve the arc starting characteristics and the longevity of the Tungsten electrodes. In the orbital welding industry, the most commonly used electrode materials are two percent thoriated Tungsten and two percent ceriated Tungsten. So what are the advantages to using these two different types of electrodes instead of a pure electrode?

Pure tungsten melts at a lower level temperature. This causes it to easily form a rounded ball at the tip. When the ball at the tip grows too large, it interferes with the ability to see the weld puddle. This causes the arc to become unstable. Obviously, instability is not good.

Ceriated Tungsten can withstand higher temperatures and works very well with the newer models. This is because is holds onto a point longer than a pure electrode, and it starts well at low temperatures. It can be used on bath AC and DS polarities as well. When welding aluminum, it has become very acceptable to grind a point on ceriated tungsten. This also allows welding amperages to be increased by twenty-five to thirty percent compared to pure tungsten of the same diameter.

Thoriated Tungsten allows for easier arc starting. It currently has a higher capacity than ceriated tungsten. It also provides greater arc stability. These electrodes have a longer lasting life and they have a high resistance to weld pool contamination. It is difficult to maintain balled end on AC however.

Overall, it is obviously that using a pure tungsten electrode is not recommended. It is best to use a two percent ceriated tungsten electrode or a two percent thoriated tungsten electrode. Using one of these two electrodes will work the most efficiently with the orbital tube welder.