steel+copper

I have welded copper to steel with MIG/MAG several times. But the copper was thinner (2mm). Current was in the ballpark of 100A. You need a lot of power and aim the arc more to the copper than the steel. With the 8mm copper, I even would think about pre-heating it.

Didn't TIG it, can't say.

Power!

Nick

I would look at doing this with a silicon bronze, or some other "bronze" type filler metal. You do not want to melt the steel and copper together, they are metallurgicallly not compatible and the weld would likely have severe solidification cracking. The bronze type filler is more of a "braze weld" where the base metal is not melted.

I would probably silver solder copper to steel.

Dan

If I think of all the chrome-plated rims and handle-bars, I am really frightened!

Nick

Nick, I assume you are talking about a copper layer between the chrome and the steel? If that's the case, the copper is plated on, the steel and copper are not melted and mixed together in any way. If you are talking about welding through chrome/copper plating, this is not a good idea for something critical to safety, but probably the amount of copper in the plating is small enough not to cause catastrophic cracking.

Nick Mueller wrote:

Right!

Welding copper to steels also doesn't mix it. You have the same process like with brazing (brass also contains copper, like silver-solder). It is only diffusing (at different degrees) on the contact area.

Look at it as kind of "reverse" process of MIG-brazing (don't know how you call it), that uses Al-bronze or Si-bronze (both Al or Si in the 3% range, rest is copper). You replace the bronze with steel and have nearly the same effects on the boundary copper-steel.

Nick

I second the silver soldier and proper flux Ed ke6bnl

2) I know the following copper alloys: a) brass b)Copper nickels, nickel silvers

A) Aluminum Bronzes B)Silicon Bronzes C)Leaded Copper D)Tin Bronzes E)Manganese Bronzes F) berillium bronzes

What sort of quantity/area are you talking about? I ask because it may be easier to buy steel which has been clad by explosive.