[TheForge] Normalize vs Annealing prior to hardening

[Paul]

Thanks James,
Do you know if the normalizing differ substantially from the annealing 
(at least as I've described it) ? My guess is that if I get the piece up 
past critical, assuming a uniform temperature throughout, and stuff it 
into a drum of vermiculite, that it will stay hot enough for the grains 
to stabilize (essentially soaking for an extended, although uncontrolled 
period of time).

Without a controlled furnace and atmosphere (to prevent excessive 
scaling and decarborization) the "slow cooling" method seems like a 
reasonable compromise. What I hope to learn is what trade-offs I'm 
making by my choice in process.

Thanks,
**Paul

On 6/4/2013 2:06 AM, James Binnion wrote:
>
> To normalize one needs to hold the steel 100F above the austenizing temperature for an extended period of time (15 min-1 hr) then air cool. This extended time is needed to allow all the steel to convert to an austenite grain structure. This will result in a uniform, fine pearlite grain structure upon cooling. Whether you should do it will depend on the steel you are working. If the steel air hardens then normalizing is not a good idea because it can lead to cracking in the steel. So W-1, 1095, O-1 etc will benefit from normalizing but high alloy tool steels (A2, D2, H13, S7 etc.) are typically not considered good candidates for normalizing.
>
> James Binnion
> jbin at well.com
>
>
>
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