Lanthanted Tungsten (Color Code: Gold 1.5% or Blue 2.0%)
Lanthanated tungsten electrodes (AWS classification EWLa-1.5 or EWLa-2.0) contain a minimum of 97.80 percent tungsten and 1.30 percent to 2.0 percent lanthanum, or lanthana, and are known as 1.5 percent or 2.0 percent lanthanated. These electrodes have excellent arc starting, a low burnoff rate, good arc stability, and excellent re-ignition characteristics—many of the same advantages as ceriated electrodes. Lanthanated electrodes also share the conductivity characteristics of 2 percent thoriated tungsten. In some cases, 1.5 percent lanthanated can replace 2 percent thoriated without having to make significant welding program changes.
Lanthanated tungsten electrodes are ideal if you want to optimize your welding capabilities. They work well on AC or DC electrode negative with a pointed end, or they can be balled for use with AC sine wave power sources. Lanthanated tungsten maintains a sharpened point well, which is an advantage for welding steel and stainless steel on DC or AC from square wave power sources.
Unlike thoriated tungsten, these electrodes are suitable for AC welding and, like ceriated electrodes, allow the arc to be started and maintained at lower voltages. Compared with pure tungsten, the addition of 1.5 percent lanthana increases the maximum current-carrying capacity by approximately 50 percent for a given electrode size.