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

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.

--
Paul
In bocca al Lupo!
.

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