[TheForge] Normalize vs Annealing prior to hardening

[Paul]

Thanks Kim,
This is one of the things that confuses me. If I bring the steel back up 
to austenitic, doesn't the grain structure start to change and grow?
So each time I return to super-critical, I intuitively feel like I 
"undo" the previous normalization.

I have read about reducing grain size by repeated normalization, but I 
guess I don't understand what is happening in the steel. I'm having a 
hard time accepting it because it doesn't seem logical to me.

The pieces I harden aren't being used to smash stones or in any 
life-threatening application. So I have been able to get away with what 
I've been doing with reasonable success. But I've started making some 
hammers, and I'd like them to last, and also not have any threat of 
eventually exploding from work hardening. Hence my search for more 
information. (BTW, I'm using 1045 for my forging hammers. So far, they 
seem to be hard enough without any obvious embrittlement.)

**Paul

On 6/3/2013 10:37 PM, Kim George wrote:
> I normalize 3 times then quench. Heat past critical check for warps
> straighten then reheat. I let it cool in still air on two pieces round
> stock.By doing it 3 times you relieve the stress in stages.
>