Super duper CPM-s3v heat treatment recipe?

JG Custom Metal Works

JG Custom Metal Works

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Nov 27, 2013
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I keep seeing folks claiming a really great s3v heat treat. Some confirm the claim by doing some very substantial torture tests.

What I'm wondering is, other than the HT procedures for s3v listed by crucible or Alpha Knife maker, what are people doing to achieve such good results? I know people spend a good amount of money, effort, and time getting it just where they want things and may not be so keen to announce the research. I get that, and that's why I'm starting this thread instead of messaging people directly. I figure if anyone is willing to share their tips on extracting every last ounce of plus plus good knife stuff from heat treatment, they would share.

I'd very much appreciate it as I have a few 3v blades in the works right now. The 3v I've been using up until this point has been working very well, but am always trying to improve.
 
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Cryo as part of the quench and low 400F MOL temper seems to be the key.
 
1250f 10 min, 1550f, 10 min, 1950f 30 min, plate quench, cryo 12h, then 400f temper 2hx4, water quench between each temper. Should be Rc60/61 consistently.
 
Hey Willie, just curious, why the 12 hour cryo and the 4, 2hour tempers?

Did that give better results then just a standard 2-3hr LN and 2 tempers?

Thanks man.
Shawn
 
Willie71 said:
1250f 10 min, 1550f, 10 min, 1950f 30 min, plate quench, cryo 12h, then 400f temper 2hx4, water quench between each temper. Should be Rc60/61 consistently.
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Perfect! Easy-peasy. Thanks Willie! That's pretty close to what I have been doing.
 
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Willie71 said:
1250f 10 min, 1550f, 10 min, 1950f 30 min, plate quench, cryo 12h, then 400f temper 2hx4, water quench between each temper. Should be Rc60/61 consistently.
Click to expand...

I do basically the same except I only do 3 tempers
 
No snap temper. You defeat the purpose of the cryo if you do the snap temper. 12h cryo gives you eta carbides. Four tempers might not be needed. Three is probably good enough. I do four with z-wear.
 
Snap tempering essentially "locks in" a certain amount of RA, that won't then convert in cryo, right?

Willie71 said:
No snap temper. You defeat the purpose of the cryo if you do the snap temper. 12h cryo gives you eta carbides. Four tempers might not be needed. Three is probably good enough. I do four with z-wear.
Click to expand...
 
DeadboxHero said:
Hey Willie, just curious, why the 12 hour cryo and the 4, 2hour tempers?
Did that give better results then just a standard 2-3hr LN and 2 tempers?
Thanks man. Shawn
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I think the idea is that one temper (or two) doesn't convert all the RA - that each time you do a 2 hr temper a bit more RA gets converted.
 
Ken H> said:
I think the idea is that one temper (or two) doesn't convert all the RA - that each time you do a 2 hr temper a bit more RA gets converted.
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Yes, this is my understanding. Chuck at AKS relayed to me, that a rep recommended three tempers, and that a fourth was a good idea, but most people are turned off by that idea. When I heat treat 3v or z-wear, I have an evening, then the next day free to commit to the process. It might be overkill, but I know for sure it's not inadequate.
 
I was just looking over on Alpha Knife Supply and they had the data sheet on 3v there. It said to temper at 1000f-1050f. That's a pretty big difference than the 400f recommendations I'm getting here. I wonder what's up with that? Not doubting anyone here, just wondering why the data sheet would say that...
 
Also, when hardening, do you guys but your knives in prior to the oven reaching the target temp of the first stage(1250f), or wait until it reaches the temp and then put it in? I've always waited until it was at temp for the first stage, then put it in. I've always gotten good results from doing that. The other day a maker was telling me how he put his in for the entire ramp up to temp. That doesn't really make much sense to me.
 
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The data sheet is for industrial use, and the high temper is needed for secondary hardening and conversion of retained austenite. Cryo is optional and not part if the quench.

The low temper method gives you better fine edge stability, and uses cryo as part of the quench, needed to convert the retained austenitite. 400 temper without cryo wouldn't work as you would stabilize the retained austenite rather than convert it to matensite.
 
JG Custom Metal Works said:
Also, when hardening, do you guys but your knives in prior to the oven reaching the target temp of the first stage(1250f), or wait until it reaches the temp and then put it in. I've always waited until it was at temp for the first stage, then put it in. I've always gotten good results from doing that. The other day a maker was telling me how he put his in for the entire ramp up to temp. That doesn't really make much sense to me.
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The ideal would be three ovens, each set to the desired temps. Ramping isn't ideal, but it's the best we can do with only one oven.
 
Great! Thanks again Willie. Got my dewar filled today and am gonna get cracking here in a few minutes.

Thanks to everyone else too! I appreciate the help, as always.
 
Snap temper not necessary. If you are the nervous type you could hold above the LN for a while then dunk into the LN .Suspend the blade ,don't lay it on the bottom.
eta carbides form only upon tempering !! Don't temper high ,use 400 F for blades .2X maybe 3X should do it .12 hours at - 300 F ? I've been recommending 6 hrs but I'd like to do some testing for that . Each type of steel has different times here !! The whole cryo thing is weird .But I now understand [after years of searching ] the process so it comes down to tweaking.
 
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