Copper Welding Wire Electrode
A solid welding consumable for GMAW welding of copper and copper alloys with a specific surface finish. The copper coating primarily serves for corrosion protection and improves electrical contact transfer.
Copper in welding wire is not an additive applied to the weld, but mostly a thin coating on the wire. Its main purpose is to protect the wire from rust and ensure better contact in the contact tip. During welding, the coating melts and goes into the weld pool.
Too much copper in the weld metal is not good; it makes the weld brittle and prone to cracking. With normal copper-coated wires, the amount is so small that you don't have to worry about it. It's standard and works fine.
If you're welding with actual copper wire or flux-cored wire with copper content, then: keep away for normal steel welding. That's special stuff for hardfacing or joining copper materials. For normal steel, just use the standard wire, which is coated and good.