Plasteel

Plasteel was a grade 2 premium scavenged compound crafting material.

Source
Plasteel could be gathered from a Chanlon Vehicle Debris node, which required 80 skill in scavenging. It was most commonly found on Taris,  Balmorra, and Nar Shaddaa.

The following materials could also be found in Chanlon Vehicle Debris nodes:

It could also be obtained from grade 2 scavenging missions. Additionally, there was a chance to obtain Plasteel from reverse engineering the appropriate level and type of gear.