Metal Casting Zone

So I was messing around melting some bits of copper in a steel "cup" to make interesting objects for jewelry. I poured it onto a steel plate and worked it with a hammer...etc. When my cup cooled, it was covered in slag (yes, red hot, it was) so I sand-blasted it of and to my surprise, the entire thing was coated in copper, inside and out! The steel plate was also copperfied in the spot where I poured the blob.

What did I do? Did the copper "soak" all the way through the steel and get deposited on the outer surface? Is this long-lasting like electro-plating?

Forgive my ignorance if this is common knowlege, but I have no idea what happened.

Here is a pic of it next to one in its original state:

wow! i dont know. the other day i tried to melt some copper but my furnace wasnt up to the task like you i used a steel pot and noticed that although i hadnt melted the copper the pot has a copper look to it. my copper scrap had the usual green coating of oxide on it so my guess it had something to do with the copper oxide and the steel at high temp.

So in theory, a piece of steel glowing red dipped into a crucible of molten copper might become coated in copper. This might be an interesting way to patina a piece of steel sculpture! The problem is obtaining that much copper for cheap. The way things are right now, I don't think anyone is going to part with scrap metal, especially copper. I'll have to find a plumber who feels it's not worth his/her time saving tiny bits of tubing and used fittings.

I'll experiment some more and come back with updates.

Basically the copper brazed itself to the surface. Instead of it being localized like you were joining two pieces of steel to each other, it coated the entire surface. This is why if you have a steel ingot mold for pouring excess copper or brass in after you pour your mold, make sure the ingot mold is rusty, the oxide layer will prevent the brass/bronze/copper from brazing to it. That is why a lot of first time casters ruin their muffin tins when they can't get the ingot out.