It's a "discada" or "Cowboy Wok"
It's used for cooking over a fire. Made from an old plow disc and a couple of used horseshoes (Thanks Britta). I added removable pipe legs to hold it over our propane campfire. 22" in diameter, oughta hold enough for Kat and I...
Easy to make, except for the hours of grinding to remove the rust pits... Next time I'll just buy a new disc that's not all rusty.
Sam