Thermacycle : Researching Metal Treatment

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Can I infer from your statements that by cryo treating a knife made of 52100 I will see a 400+ % increase in the wear resistance (edge holding??) of said knife?

-Mike-
 
I'm not really going to get into this, but wanted to clear up one thing.

I never stated that cryo doesn't work ( I cryo all my stainless blades). I only stated that most sellers of any process or product state that theirs is far superior to the others. Some are bogus from the start, and some are merely the same as all the others.

I will leave the discussion of what steels benefit and to what degree, to the metallurgists and engineers. As far as 52100 goes, well, I couldn't say.

If my post conveyed the impression that i don't believe in cryo, please note that I do.

Stacy
 
micad said:
Can I infer from your statements that by cryo treating a knife made of 52100 I will see a 400+ % increase in the wear resistance (edge holding??) of said knife?
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Mike, when the deep cryogeneic treatment is done with the correct profile (meaning not a dunking in liquid nitrogen then whipped out again) 52100 will exhibit 400+% gains inb wear resistance. It has been proven in research papers under controlled conditions, and those research papers have been replicated by other people with repeatable results.

My real intent with spending the time in this thread was to see what profiles people are using, see if anyone knew anything about this thermacycle patent pending process and to expand my knowledge of what profiles are being used.

After many phone calls to shops in my country and digging through papers the one profile accessible to me is a slow progressive 24 hour cool down, 24 hour at -310F and then 24 hours back to ambient temps. Its the only one the shop was prepared to do in my area. Im trying to identify other profiles and better understand what might be an optimal set of heat treating and deep cryogenic treatment for 52100 blades.
 
im just a poor knife maker all i can do is "dunk" my blades in LN over night and then pull them in the morning let them warm to room temp and then temper them

i think it helps some steels but not all

if what you are doing is reading papers and then making your own paper of your thoughts on other papers. what are you really doing? how bout tring a few "profiles" and lettign us know what YOU find not what you read and speculate

we here are the type that have little problem heat treating many different ways then braking the blades to see and even to send off to get tests done
we also post what we find to help other makers both good and bad that happens

i think you will find little in the way of BS or snake oil here by the main posters as those that play that game are soon shown to be just hype mongers
 
I think that the 420% increase only works if you use the special medical grade charcoal and aren't willing to share information to communist parasites. :D

While I find the whole cryo treatment talk interesting, I don't really find it that useful on the simple steels I forge.

Remember there are lies, damn lies and statistics. :D
 
nullack said:
http://www.angelswordstore.com/index.php?option=com_content&task=view&id=37&Itemid=70
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The Charpy comparison states that they are comparing their own independent Charpy test with the numbers from Crucible. The problem is, Crucible uses a Charpy C-notch, which is a notch they created/modified for their own purposes, as a Charpy V-notch (the standard), gives very low values for most tool steels; it's hard to compare toughness when all the values are between 1 and 2 ft. lbs. Anyway, I don't believe that they asked Crucible what the parameters of their test are, then tested it that way, yet they are comparing values. I'm having serious doubts that they did anything but make up the numbers. If they really did Charpy tests they would have just compared it with a standard heat treatment rather than using Crucible numbers. If a representative of the company will truthfully back up the numbers I'll reconsider, but for now I'm going to call BS.
 
nullack said:
Mike, when the deep cryogeneic treatment is done with the correct profile (meaning not a dunking in liquid nitrogen then whipped out again) 52100 will exhibit 400+% gains inb wear resistance. It has been proven in research papers under controlled conditions, and those research papers have been replicated by other people with repeatable results.

My real intent with spending the time in this thread was to see what profiles people are using, see if anyone knew anything about this thermacycle patent pending process and to expand my knowledge of what profiles are being used.

After many phone calls to shops in my country and digging through papers the one profile accessible to me is a slow progressive 24 hour cool down, 24 hour at -310F and then 24 hours back to ambient temps. Its the only one the shop was prepared to do in my area. Im trying to identify other profiles and better understand what might be an optimal set of heat treating and deep cryogenic treatment for 52100 blades.
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Nullack,

I figured that this would be your response. My specific question had to do with directly equateing the supposed 400+ % increase in wear resistance to an equal increase in edge rentention. Not sure you directly asnwered that.

A few years ago I ground a few blades of diff. steels to test what cryo would do to the blades in terms of edge retention.

Two blades each of 1084, ATS34 and 52100. I heat treated each blade in a friends shop and immeditately took one of each to a local cryo company (iirc it was known as 300 below) that made the same claims about 400+ % improvment in wear resistance. They used a pretty sophisticated computer control process that took over 24 hours to complete, with blades spending about 18 hours at -310 deg.

The other three I finished heat treating with my normal temper and no cryo. I had each blade checked for hardness and the cryo'd blades showed a point or two higher than the non-cryo'd blades.

What I found in my very limited test was that, in terms of edge retention that1084 had vary little gain, perhaps (iirc) about 3%.
52100 showed a little better, again iirc, about 7-8%.
ATS34 showed about twice what I saw with 52100.

My cutting test was simply to count the number of cuts made on a 3/4 diameter manila rope. When the blade started to skate I resharpened and tried again (three times for each blade).

Not the most scientific of tests, but if the cryo did what they claimed and gave a 400% improvment I certainly would have seen HUGE differences between the two sets of blades. I did not.

Again, all this was a few years ago and my memory is not the best so those percentages may be off a few points, but the point is that the wild claims of 400+ % improvements in wear resistance are just that---WILD claims.

I do believe that most blades will benefit from a good cryo treatment, but nothing near 400%.

Your results may vary.........


-Mike-
 
Mike thanks for the info that's exactly what Im after :)

My initial hunch is that the profile of the treatment you used and the profiles being used today are quite different - 3days vs 1day. US Government spent significant amounts on research with NASA, Dept of Energy and military groups....along with allot of money from the industrial tooling industry. The profiles are changing rapidly as more is learnt.

I believe the art to it will be in the profile much as it is with heat treating.

Anyway I have a sample booked in, there is a three week wait on the shop as its a small job but Ive booked it now.
 
Also Mike, can I quickly please comment on the assertion about those papers making "wild claims". They are actually very specific test results obtained under specifically controlled tests. I think its more fair to say the work of what those research people have done is to say that your application should be considered a different situation with different testing outcomes. It doesnt make scientific research papers useless.

I think once the samples are back and if I replicate results like yours, theres lots more questions. What and why is it different? Is the profile wrong? Does deep cyro require different blade geometry to be optimal? and so on and on. In science understanding it is most of the battle in being able to improve it in my experience.
 
Well, I find it hard to believe that the profile can have much to do with what happens to a steel structure when cyro is preformed. On an atomic level the edge of a blade is huge and if you looked at even a razor sharp edge at an atomic level, I bet it is hardly smooth in any profile. How can that be possible. This doe not make any sense Jim
 
I was simply giving some possible questions to consider if my tests do not correlate to the 420% wear resistance. This is all part of normal science - when people cant replicate others test results more inquiry is needed to understand why. The example questions werent meant to be serious, sorry if that was understood.

I do appreciate the difference between edge retention and wear resistance. In fact plastic deformation of an edge can be modelled on a computer all day doing what if analysis using finite element analysis.

Adding to Busse, Bark River Knife Tool guru Mike Stewart is quoted as saying:

"I cryo treat all of my blades and have since I found out about the Process in 1987.

Cryo Treating in the Heat Treat Process is usually done between first and second Temper or for some Steels--Before the First Temper.

Some steels respond just fine at about -115 and others need the Full -300 process.

I hate to be a dingle but How I do each steel is not open to Discussion.

It is one of the Few things I do not share."

Please not I dont Agree on his -115f comments and neither does research paper test results. Full deep cryo is the place to be for steels.

Also note like Busse he wont reveal his thermal cycle profile. If any of you are serious about true high performance knives then I am convinced more collabaoration is needed between us enthusiasts if we want to match the professional companies. Afterall, anyone can buy a given grade of steel as raw material......the difference between poop and poetry comes in processing.
 
nullack said:
If any of you are serious about true high performance knives then I am convinced more collabaoration is needed between us enthusiasts if we want to match the professional companies. Afterall, anyone can buy a given grade of steel as raw material......the difference between poop and poetry comes in processing.
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Soooo if I don't join you in this cryo tempering process I'm not serious about high performance blades? :mad: Match the professional companies in what exactly? sales volume? :jerkit: While I agree that a bad process can turn good steel into barely usable trash, a good process turns out a good blade given a good blade steel at the start. Blade steel choice is just a starting point for a knife design.

I'm not going to join you in this cryo stuff, I've already conducted my tests. I guess I'll continue to make poop. BTW, we "enthusiasts" DO collaborate, that's what these freaking forums are for, we've been "collaborating" for quite a while.
 
Will your lack of courtesy is ugly and unnecessary.

Perhaps I did not express it very well. It just seems to me that busse and bark river and all the rest for obvious reasons dont want to collaborate on their process. Therefore the enthusiasts are left to themselves in that sense and thats why collaboration is important. Its a general comment thats not restricted to cyro, its about the whole processing of steel.

I have not even finished my tests so I dont have any results or conclusions of my own.
 
nullack said:
Will your lack of courtesy is ugly and unnecessary.

Perhaps I did not express it very well. It just seems to me that busse and bark river and all the rest for obvious reasons dont want to collaborate on their process. Therefore the enthusiasts are left to themselves in that sense and thats why collaboration is important. Its a general comment thats not restricted to cyro, its about the whole processing of steel.

I have not even finished my tests so I dont have any results or conclusions of my own.
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Whatever...... I edited my last comment because it may offend, I'll post after I finish coffee.
 
I'm with you Will.....I guess if we aren't a production company, we're "enthusiasts":rolleyes:

The internet is a funny thing. Funny how people "discover" something and say they are "convinced" or "you must do this".........otherwise you're a hack-- and you new about it , tested it, tried it, BTDT years before.

There's been quite a few people with magical heat treating processes, that are no longer in the business.
I find it odd that if these 400%+ claims are true, that ANY industry that uses 52100 doesn't use the process ( oh I forgot, it's super secret)
 
Ssheperd -

1. Do you think it is necessary for hobbyists to test every aspect of engineering for themselves before its trusted? Clearly youd never make a knife before you died of old age re-inventing the wheel.

2. Since there is inconsistent test results I am going to the time and expense for me personally to test deep cryo for knives. I am in fact testing it myself, in an open and honest manner.

3. Your claim no one uses deep cryo on 52100 is utterly false.

Its a sad reflection on the character of certain people on this forum that they think they have the right to be abusive. Wills first post was nonsense, his second jumped to conclusions I havent made inferring Im a wanker. Ad hominen attacks arent logical ways to proove an argument. Then his third post is more dribble on ad hominem topics which hes now edited.

You both need to get some maturity and rational thinking skills.
 
hardheart said:
I'll quote Busse and Mike Stewart.
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Thats a straw man tactic.

I quoted research papers showing test data and conclusions. Thats the premise, the data. I later discovered Busse and Stewart were doing it too, which is fairly relevant. Its not however my main premise. To suggest it is, is misleading.
 
http://www.airproducts.com/NR/rdonl...019GLB.pdf#search="cryogenic quenching steel"

The above linked article represents an independent study on the effects of various deep cryo treatments on tool steel (A2). Note that although the cryo treated A2 gained as much as 3 point HRC, it lost impact resistance.

I still cryo stainless steel blades, but no longer do it for the tool steels.

Just one question if you don't mind. What do they mean when they cite 420%? What are the quantitative parameters for deriving a 4.2 times gain?
 
Thanks for that Steve its always good to see more papers.

Im not all that interested in minor improvements of hardness - the real benefit is to wear resistance. Besides I could work harden the blade through plastic fracturing for more hardness anyway outside of heat cycles. The toughness issue is new to me so Ill look at that. Good to see another paper confirm the small carbides structure as well.

Read the papers in full for their test methods. Thanks again.
 
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