1.5% lanthanated tungsten electrodes (AWS classification EWLa-1.5) contain a minimum of 97.80% tungsten and 1.30 to 1.70% lanthanum, or lanthana. These electrodes have excellent arc starting, low-burn-off rate, good arc stability and excellent re-ignition characteristics—many of the same advantages as ceriated electrodes. 1.5% lanthanated electrodes also closely resemble the conductivity characteristics of 2% thoriated tungsten, meaning, in some cases, it can replace 2% thoriated without having to make significant welding program changes.
1.5% lanthanated tungsten electrodes are ideal if you want to optimize your welding capabilities. Lanthanated electrodes 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. The lanthana is dispersed evenly throughout the entire length of the electrode during manufacturing. It also maintains a sharpened point well, which is an advantage for welding steel and stainless steel on DC or the AC from squarewave power sources.
Unlike thoriated tungsten, these electrodes are suitable for AC welding and, like ceriated electrodes, allow for the arc to be started and maintained at lower voltages. AC Compared to pure tungsten, the addition of 1.5% lanthana increases the maximum carrying capacity by approximately 50% for a given size electrode.