Originally posted by: raptor13
Easy question.
That is very clearly a micro-pictograph of steel. You can very clearly see the layered pearlite crystalline structure(where the black stuff is) intermixed with a bainite matrix. It looks to me like a relatively high carbon steel, perhaps SAE 1045 or 1060, but it's hard to tell especially since we don't know anything about the processing that metal went through. I'd guess it was normalized... it sure wasn't quenched.
NEXT!
P.S. Yay for school!