Shadow.

[Alarion]

I've seen on vairous occasions reference to a separation between perlitic and austenitic crystalline structures in hot steel called the "shadow". According to what I've read it should be something fairly simple to see, but even if I observed carefully some pieces of steel get hotter and hotter, I couldn't see anything.
Can anybody explain it better to me and give some advice on how to see this phenomenon?

 

[Sweany]

The phase change does indeed throw a shadow across the steel. Harder to see in a gas forge. easier in coal or charcoal. Dim light like moonlight helps a WHOLE GREAT BIG BUNCH. I can see it in my little gas forge if it is dark, can't see it in daylight or with shop lights on.

Heat very slowly, to much blast will coalecse the outside of the steel before tyhe center reachers temp. and you won't see it.

too much blast is not a good idea when trying for hardening temp anyway.

 

[Alarion]

Thank you for both the tip about the shadow and the heat treating.
I'm a real rookie and every bit of advice is highly welcome