Normalizing O1?

J

jawilder

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Jun 27, 2006
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I have started using O1 more often since I can get it PG in thin stock. My HT routine is:
- Preheat oven to 1200 for 20 minutes
- Insert blade for a 20 minute stress relief cycle
- Ramp blade within 10 minutes to 1480
- Let blade soak for 20 minutes
- Quench (still playing around with various quenching mediums: Peanut Oil, Canola Oil, Parks 50, Aluminum Plates, Edge quinch only, etc)

I don't do any grinding pre HT on the 3/32 stock I am using so I don't generate any uneven heat except during the profile process.

My question is, I would like to refine the grain, so that means I should normalize - 1600, 1500, 1400. But do I still need to give the steel a stress relief cycle if I normalize? If so, should I normalize, then relieve stress, then soak? Or should I relieve stress, then normalize, then soak?

What do you think?
 
the blade should be in an ideal state for hardening when you get it. No need to normalize. The only reason I see for a stress relieve cycle is that it was sheared, whick can induce stress.
 
The only reason I suggest that it might need normalizing is that I broke a blade to look at the grain and wasn't all that happy with how it looked. I mean, it wasn't too bad but I would like to refine it even further.
 
You might wanna consult Kevin Cashen ( http://www.cashenblades.com/) directly on this question. Maybe even have him look at what you didn't like. He has some SERIOUS microscopes....................

Syn
 
What are you comparing the grain of the broken blade to that makes it unsatisfactory?
 
The stress relieving cycle is added insurance against warping. Normalizing cycles will refine grain and accomplish the same thing in reducing the chance of warp. So, unless you are inducing uneven heat into the steel after normalizing, there is no need to stress relieve prior to HT.
 
Rick, it is my understanding that the steel goes through quite a bit of stress through the rolling and PG process. Enough to warrant a stress relief cycle.
 
I was talking about normalization cycles done by you. After you do it, there is no need to stress relieve, IMO. Unless you are grinding the crap out of it. I would ALWAYS run grain refining cycles on bar stock. You never know what nasties are induced at the mill.
 
Rick Marchand said:
So, unless you are inducing uneven heat into the steel after normalizing, there is no need to stress relieve prior to HT.
Click to expand...

Sorry, didn't catch that part. So you say to normalize only and forget about stress relief if forging as well as stock removal. I suppose that makes sense. So then under which circumstances should steel go through a stress relief cycle?
 
Forging should always be followed by normalizing.
If you're not forging then stres relieving is used to remove stresses that may cause warping during HT .
 
jawilder said:
Sorry, didn't catch that part. So you say to normalize only and forget about stress relief if forging as well as stock removal. I suppose that makes sense. So then under which circumstances should steel go through a stress relief cycle?
Click to expand...
I would normalize everything if you have the means. Unless you have certs from the mill (CPM stuff comes to mind) you can only hope that the internal structure is consistant. If you are forging, it is a must. Stress relieving would come into play only if (after normalizing) you do heavy grinding or cold working(straightening). Stress relieving will not refine grain.

You could probably get away with simply stress relieving barstock from the mill. I like to have more control over the internal structure(thermal cycling) and feel I gain more consistency doing so.

Rick
 
if your not happy with the grain size... normalize it
-and add abit of a soak to each step of the normalizing ...
o1 is a great steel with a fine grain, i like it alot
 
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