Re: "steel" vs "iron" [was:Re: Competing unions [was: Re: Native English]]

Paul Wolff <bounceme@xxxxxxxxxxxxxxx> wrote:

In message <1hcfsxm.1pbvzja1l4zf7yN@xxxxxxxxxxxxxxxxx>, J. J. Lodder
<nospam@xxxxxxxxxxxxxxxx> writes
Paul Wolff <bounceme@xxxxxxxxxxxxxxx> wrote:

Cast iron doesn't refer only to how much carbon is included in the
alloy, but also to how the metal was formed and processed, which
affects its molecular grain structure to give it the properties it has
for holding a shape and retaining its hardness. The amount of carbon
involved in the alloy is tiny; we're talking less than 0.5% or so. The
molten compound is poured into molds that create the shapes desired.

Cast iron generally has much more carbon than this, typically 2 to 4
percent. Blast furnace iron product is treated for steelmaking
primarily by burning off the excess carbon and removing other non-metals
with oxygen.

What's the differencew between 'burning off carbon'
and 'removing other non-metals with oxygen'?

I first wrote 'burning off carbon and other non-metals' but then I
decided that as a matter of usage 'burning off' could imply all gaseous
products. After carbon the next major non-metal that needs removing is
silicon which goes into the slag with much of the phosphorus. Phosphate
slag is a valuable fertiliser. I'd guess that sulfur goes both ways, to
sulfur dioxide gas and sulfate in the slag. But I'd have to ask a
steelmaker for the real life answer, or even look in a book.

I see, thanks,

Jan
.

Relevant Pages