http://www-g.eng.cam.ac.uk/mmg/teaching/typd/index.html

Check out this link if you are interested in finding out how steel changes with heat.
Do a Web search "iron carbon phase diagram" Thanks Mete.

Jerry

Chemical phase diagrams may have several axes that plot different things. The version that is of most interest to knifemakers plots temperature against time, t-T plot. This diagram only shows stable phases and excludes the quenched (metastable) areas, i.e. Martensite and Bainite. To view this you would need to look at flat slices cut perpendicular through this one at the point of the Fe-C composition of your steel.