[Physics] Why does carbon alloy with iron specifically


Everyone knows what an alloy is: it's a metal made by melting two (or more) other metals together.

Unless of course you're talking about steel. That's a metal made by mixing carbon (very much not a metal) into molten iron. But you never hear about carbon alloys with any other metal, and that's kind of strange. If a few percentage points of carbon can turn iron into the miracle metal that is the foundation of the Industrial Age, just imagine what it could do to aluminum or titanium, for example. (Or even bronze, for that matter, which is superior to iron in many ways, from a materials science perspective.)

But you only ever hear about carbon alloying with iron to form steel. So what's so special about iron?

Best Answer

It's true they are not common, but there are other alloys that use carbon. Nickel is probably one of the more common metals that form alloys with carbon that have desirable properties. For example, Nickel 200, Nickel 201, and Nickel 205 all contain carbon. (See: http://www.asminternational.org/documents/10192/1852239/ACFA9D7.pdf/d490dee6-620e-4e38-b64d-53dd02c5fc81). Chromium and Tungsten also form alloys with carbon called Stellite Alloys: See http://en.wikipedia.org/wiki/Stellite (although some, but not all, stellite alloys contain iron too).

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