heat treating help

[mariobab]

Sometimes things just happens.The other day I have found forgotten axe head,old and missused,in fact , hatchet,rusted and dented ,and next day reading thread http://www.bladeforums.com/forums/showthread.php?t=535626,said to myself,lets play a little,ant try some tips given there.So I heated,cooled it,annealed,and OK it works.But what worries me is that on head surface is some thin crust,some can be pealed off,some not.What and why is that?I`m not a blacksmith, I never forged anything,so don't mind me asking silly question.

 

[Chris Meyer]

Sounds like scale from oxidation in the forge. You could try wire brushing it, but most people just grind it off. I've heard it can also be removed by soaking the steel in vinegar or similar, but I've never tried it myself.

I'm assuming you realize that you'll have to re-harden and temper the axe head if you intend to make it a useful tool again. If you can find out what type of steel it's made out of, you can look up the proper heat treating temps for it. Otherwise, it's essentially guesswork.