Tungsten is ideal for transmitting the current needed for welding to the arc as it is sturdy and has a high temperature resistance. To get the job done properly, like in any other industry, you need the right equipment with each component playing its role to perfection. The tungsten electrode, which is a non-consumable metallic element that has the highest melting point of any known metal, is a core component of the TIG welding tungsten process.
Making a decision on the type of tungsten for the TIG welding tungsten task is not difficult at all but needs one to have a given level of awareness. Tungsten electrodes are available in a variety of diameters ranging from 0.040-5/32’’ which are the industry standards but can also come customized, though a bit more expensive.
The tungsten are made of pure or hybrid tungsten, other earth elements and oxides. To prevent confusion, the tungstens come bearing different colors on the tips. Here are the different types of tungsten electrodes:
Pure tungsten (green in color)
These as, stated above, are the most widely consumed in TIG welding tungsten and contain 99.5% tungsten as a component. However not used for DC welding, the pure tungsten provides a good, clean and stable arc AC welding mostly on aluminium and magnesium.
2% Ceriated (Orange in color)
These are popularly found in thin metal welding because of the low amperages and contain 97.3% tungsten and the rest cerium as components. These orange tungsten electrodes can be used proficiently for both AC and DC TIG welding tungsten but favor DC welding more. In recent time, 2% ceriated tungstens have been used more than pure tungstens as they provide more current-carrying capacity.
1.5% Lanthanated (gold in color)
From its name, you would know the tungsten electrode contains 1.5% of lanthana and the rest tungsten as composition components. These closely resemble 2% thoriated tungstens and can increase the carrying capacity by more than 50%. Among its characteristics, it burns slowly, re-ignites easily, has a sharp edge and has good arc stability. They can be used for both AC and DC TIG welding tungsten but favor AC welding more.
Rare earth (gray in color)
Because of the various rare earth oxides and hybrid combination additives, the rare earth tungsten electrodes provide a stable arc in both AC and DC welding, offer lesser tungsten spitting and last longer than thoriated tungstens.
2% Thoriated (color is red)
Preferred for their ease of use during TIG welding tungsten, the Thoriated tungsten electrodes have a minimum of 97.3% tungsten and the rest thorium. They are also one of the most widely used electrodes in the welding industry as they also offer a higher current carrying capacity while operating below its melting temperature than the other types. This slows down the consumption rate considerably and promotes stability during TIG welding tungsten process.
Tungsten can be prepared for specific welding in three different ways, balled, pointed or truncated depending on the type of tungsten electrode chosen. To make the end into a ball, apply recommended AC amperage to the electrode and the ball will form itself. Pointed or truncated tips are used for thin metal welding using low current to prevent blow off and puddle contamination. A grind wheel can be used to sharpen the tungsten but be careful because some electrodes are known to contain radioactive properties. The above are the basics in TIG welding tungsten.