Need Cryo treatment

[Nathan the Machinist]

warbird436

I have had enough involvement in both university and corporate level research to know that when folks with an interest in an outcome are performing research - that outcome should be taken with a grain of salt.

I have also evaluated the use of cryo in knife blades. I use cryo. But I know, from first hand experience, that many of the claims from the cryo industry do not translate into performance in knives. The only noticeable improvement I have even seen can be attributed to reduction of retained austenite. And cryo after temper reduces the improvement to the point it is not even worth the bother. I don't pretend to know anything about the performance characteristics of cryogenically treated cast iron brake rotors. Do you pretend to know something about cryogenically treated knife steels? If so, what? Otherwise, I call bullshit - this is snake oil.

In the interest of full disclosure, would you care to tell us who you are and what is your dog in this fight? Are you affiliated with Controlled Thermal Processing, Inc?

 

[mete]

Warbird, please tell us what the "other affects" are. On another forum we gave every opportunity to a member of the ASM committee on cryo to explain . He couldn't !
What we do know is cryo's effect on RA. Tell us what happens for example with aluminum or brass .
My feelings as a metallurgist are that Cryo , except for RA reduction, is a lot of hype ,an embarrassment to me and other metallurgists.

 

[Larrin]

Phil, dunking a blade in LN2 is like water quenching D2. If you go down to quickly, you not only induce cracks, you miss some of the better happenings in a cryogenic process. You see, a lot of things are going on in metal (not only steel) as the temperature drops, but they do not happen if you go too quickly.

False.

 

[warbird436]

Fitzo:

I understand your frustration. For years people have said there is no research. When we cited research we were criticized for not publishing it so people could read it. When we publish it we get cited for not having enough.

First of all, there are new papers there. The Bensley paper is quite interesting. It takes time to put the papers in the data base because of the copyright laws. We have to get permission from the holder of the copyright in order to publish the papers

Secondly, the data base was put on the web in September, so it is not well known. I have been pointing it out to researchers so that they send their papers in. Give it a chance.

Thirdly, the data base is done by volunteers and was paid for by a cryo company. Money and time are valuable, and companies and individuals have higher priorities. We (cryo companies) see the research, so it does not help us to have the database other than we can refer people to it when they say there is no research. So it is not always our highest priority to work on the data base.

Fourthly, the data base is an extension of the one I started years ago. Most of the papers in it were ones I collected. The web presence of the data base was put together by U. S. Cryogenics which turned it into and advertisement for their company, which has caused other cryo companies to boycott it. I do not believe it was the intent of the CSA to allow this to happen, and I am certainly against having a cryo company listed so prominently. The data base should be entirely neutral.

There is a lot of new research coming into being in India and China. I have seen some interesting stuff, and will probably be putting some excerpts on my web page. There is some very interesting research into carbide formation going on at Iowa State University but it is not done and is privately funded.

Its out there and we are trying to make it public, but it is not a simple task.

Nathan:

That is why we use independent labs for testing. Independent labs are, well, independent. They come back with the data that is uncolored because they do not know what they are looking for. Are saying that NASA, Los Alamos National Lab, Illinois Institute of Technology and others somehow have an interest in cryo processing? Are you saying that when Greening Labs gets two rotors and tests them they somehow know which one is cryo'd and lean toward that one?

We do knives for manufactures who sell them on their increased performance for a premium price. These are knives that are used in industry and just work better and longer. Some are used to cut paper in newspapers. Some cut fabric in the clothing industry. Some are used in the meat packing industry.

Have you looked at the production of fine carbides? David Collins' research shows this as does some of the recent research from India. What about the reduction in point defects in the basic crystal structure? You can calculate that from stuff you learn in basic metallurgy courses for crying out loud.

As for your involvement with university and corporate level research, it only proves that you hang around with the wrong sort of people and that you are therefore also suspect. As to not knowing the performance characteristics of cryo'd rotors, it seems to me that you would want to know why this happens and what relationship that has to what you can do with other ferrous metals.

Knife steels form carbides, they lose point defects, they lose residual stresses when cryogenically treated. There is redistribution of the alloying atoms. We believe, but have not proven that cryo makes the atom to atom distances more even in the crystal structure. This reduces the energy in the crystal lattice structure. Read the research. As for being bullshit, all you offer are opinions. Without theory or research they are bullshit. Show me some theory or some research.

Who am I? I am the owner of Controlled Thermal Processing. I am Co-Chair and founder of the ASM Cryogenic Processing Sub-Committee. I work closely with CSA and am on the committee that reads and ok's the submissions to the CSA database. I have 15 years experience in cryogenic and 30 years experience in wear resistance engineering. By the way, the first time I tested Cryo it failed. Someone had dipped the part in LN2. It took a lot for me to try it again. Who the heck are you?

mete
Go to the CSA database and read the NASA paper on Aluminum and the Linde paper on cryo. You will get a lot more info than I can type out in the few minutes I have left to put to this. You offer no research to counter the claims of cryo, nor do you offer any theories or criticisms of the existing research. You call the findings of respected researchers in respected institutions "hype" and imply that they are liars without any explanation. You are much like the guys who persecuted Galileo. Come up with something substantial

Larrin:

False. Your'e IT
Tell me why it is false.

 

[fitzo]

Fitzo:

.....

First of all, there are new papers there. The Bensley paper is quite interesting. It takes time to put the papers in the data base because of the copyright laws. We have to get permission from the holder of the copyright in order to publish the papers

Secondly, the data base was put on the web in September, so it is not well known. I have been pointing it out to researchers so that they send their papers in. Give it a chance.

Thanks for the info, Rick. I found the citation for Bensley's 2005 paper about case hardened materials; hopefully it is the one you meant. Unfortunately, it is only the citation and not the article itself. It is apparently available from Science Direct, though.

I have bookmarked the CSA website and will check back occasionally to see if there are updates to the database.

 

[Larrin]

Fitzo:

I understand your frustration. For years people have said there is no research. When we cited research we were criticized for not publishing it so people could read it. When we publish it we get cited for not having enough.

First of all, there are new papers there. The Bensley paper is quite interesting. It takes time to put the papers in the data base because of the copyright laws. We have to get permission from the holder of the copyright in order to publish the papers

Secondly, the data base was put on the web in September, so it is not well known. I have been pointing it out to researchers so that they send their papers in. Give it a chance.

Thirdly, the data base is done by volunteers and was paid for by a cryo company. Money and time are valuable, and companies and individuals have higher priorities. We (cryo companies) see the research, so it does not help us to have the database other than we can refer people to it when they say there is no research. So it is not always our highest priority to work on the data base.

Fourthly, the data base is an extension of the one I started years ago. Most of the papers in it were ones I collected. The web presence of the data base was put together by U. S. Cryogenics which turned it into and advertisement for their company, which has caused other cryo companies to boycott it. I do not believe it was the intent of the CSA to allow this to happen, and I am certainly against having a cryo company listed so prominently. The data base should be entirely neutral.

There is a lot of new research coming into being in India and China. I have seen some interesting stuff, and will probably be putting some excerpts on my web page. There is some very interesting research into carbide formation going on at Iowa State University but it is not done and is privately funded.

Its out there and we are trying to make it public, but it is not a simple task.

Nathan:

That is why we use independent labs for testing. Independent labs are, well, independent. They come back with the data that is uncolored because they do not know what they are looking for. Are saying that NASA, Los Alamos National Lab, Illinois Institute of Technology and others somehow have an interest in cryo processing? Are you saying that when Greening Labs gets two rotors and tests them they somehow know which one is cryo'd and lean toward that one?

We do knives for manufactures who sell them on their increased performance for a premium price. These are knives that are used in industry and just work better and longer. Some are used to cut paper in newspapers. Some cut fabric in the clothing industry. Some are used in the meat packing industry.

Have you looked at the production of fine carbides? David Collins' research shows this as does some of the recent research from India. What about the reduction in point defects in the basic crystal structure? You can calculate that from stuff you learn in basic metallurgy courses for crying out loud.

As for your involvement with university and corporate level research, it only proves that you hang around with the wrong sort of people and that you are therefore also suspect. As to not knowing the performance characteristics of cryo'd rotors, it seems to me that you would want to know why this happens and what relationship that has to what you can do with other ferrous metals.

Knife steels form carbides, they lose point defects, they lose residual stresses when cryogenically treated. There is redistribution of the alloying atoms. We believe, but have not proven that cryo makes the atom to atom distances more even in the crystal structure. This reduces the energy in the crystal lattice structure. Read the research. As for being bullshit, all you offer are opinions. Without theory or research they are bullshit. Show me some theory or some research.

Who am I? I am the owner of Controlled Thermal Processing. I am Co-Chair and founder of the ASM Cryogenic Processing Sub-Committee. I work closely with CSA and am on the committee that reads and ok's the submissions to the CSA database. I have 15 years experience in cryogenic and 30 years experience in wear resistance engineering. By the way, the first time I tested Cryo it failed. Someone had dipped the part in LN2. It took a lot for me to try it again. Who the heck are you?

mete
Go to the CSA database and read the NASA paper on Aluminum and the Linde paper on cryo. You will get a lot more info than I can type out in the few minutes I have left to put to this. You offer no research to counter the claims of cryo, nor do you offer any theories or criticisms of the existing research. You call the findings of respected researchers in respected institutions "hype" and imply that they are liars without any explanation. You are much like the guys who persecuted Galileo. Come up with something substantial

Larrin:

False. Your'e IT
Tell me why it is false.

All you have offered is name dropping and vocabulary lessons for those unfamiliar with terms like "point defects." The research is on the side of those observing the transformation of retained austenite in steels. I gladly await the references for other studies to change my mind.

 

[warbird436]

Fitzo:

Email me and I will try to get you a copy.

Larrin:
You still have not explained "FALSE".

Name dropping? Those "names" did research. If I had said "imporant organizations" you would complain that I did not name any so there must be none.

You guys ask for some other things that happen with cryogenic processing and when you are told about some of them you accuse me of giving vocabulary lessons. Sorry, but the easiest way to talk about point defects is to call them what they are, point defects. What should I call them?


The research says that there is the transformation of retained austenite, the formation of carbides, the relief of residual stresses, and the change in the distribution of alloy elements. Here are some quotes from the research and the citations.

The following is a copy of what is on my webpage.


We are often told that cryogenic processing is bogus because there is no research to support it. Here are some quotes from research papers from a variety of sources. The headlines are ours, the quotes are from the research with minor clarifications where needed. We've quoted our sources so you can look these up yourself to assure the accuracy and read the papers. We strongly urge you to read the papers to gain a complete understanding of how these conclusions came about and their precise meaning.

1. 50 % Tooling Cost Reduction

The deep cryogenic treatment (-196 degrees C) of quenched and tempered high speed steel tools improves their properties, in particular, it increases the hardness and improves the hardness homogeneity reduces the tool consumption and the down time for the equipment's set up, thus leading to about 50% cost reduction. ...While in the AISI M2 steel the increase can be attributed to the increased hardness, in the case of AISI H13 steel the increased wear resistance can be correlated to the increased toughness.
EFFECT OF DEEP CRYOGENIC TREATMENT ON THE MECHANICAL PROPERTIES OF TOOL STEELS, A. Molinan, M. Pellizzari, S. Gialanella, G. Straffelini, K.H. Stiasny. Journal of Materials Technology 118 (2001), Pages 350-355. The above named researchers are with University of Trento, Trento Italy, and/or GKN Birfield AG. GKN is a world wide manufacturer of automotive drive line parts for OEM and replacement markets.

2. Martensite Changed by Cryo

Our recent research results have proved that the martensite formed in prior heat treatment is further changed during the cryogenic treatment.
"Cryogenic Treatment: The History, The Hype, and The Science", Yuntian Theodore Zhu, Los Alamos National Laboratory, Lecture at Illinois Institute of Technology, June 4, 2001

3. Reduced Residual Stress in Aluminum

The following results were observed for this particular Al(aluminum) alloy after cryogenic treatment:

1. Residual Stress was reduced by up to 12 ksi in the HAZ of weld specimens and by up to 9 ksi in the parent metal.
2. Significant improvements in SCC (stress corrosion cracking) performance were seen for weld specimens.
3. Minor increases in tensile strength and hardness were noted for the parent metal.
EFFETCS OF CRYOGENIC TREATMENT ON THE RESIDUAL STRESS AND MECHANICAL PROPERTIES OF AN AEROSPACE ALUMINUM ALLOY, Po Chen, Tina Malone, Robert Bond, Pablo Torres: NASA and IIT Research Institute, George C. Marschall Space Flight Center.

4. Increased Fine Carbides, Increase Wear Resistance, Increased Toughness

The effects of this deep cryogenic treatment mechanism are:
A much greater number of fine carbide particals in the microstructure.
A different partition of alloying elements between matrix and carbides, compared with conventionally treated steels.
An improvement in wear resistance of the steel.
An increase in toughness
Little or no increase in hardness.
CRYOGENIC TREATMENT OF TOOL STEELS, David N. Collins, National Heat Treatment Centre, University College, Dublin Ireland; Advanced Materials & Processes, December 1998, H23 to H29.

5. Micro Cracks Eliminated, Carbides Modified

1. There is distinctive change in the microstructure of AISI T42 High speed steel during Deep Subzero treatment.
2. The change takes place during the warming up of the steel between 8 and 16 hrs of DSZ
3. There is change in the morphology of carbides. This change contributes towards ‘rounding off’ of the irregularly shaped carbides at corners and edges in to regular round shape.
4. The phenomenon of merging / migration / dissolution of finer globular carbides takes place during the process leading to uniform distribution in the matrix.
5. The micro cracks present due to earlier processing are eliminated completely in the process.
6. The stress generated dislocations at the interface of the particles and the matrix causes diffusion, which is driven by the concentration gradient.
7. The soaking time more than 8 and 16 hrs leads excessive contraction of the matrix thereby preventing any diffusion phenomenon.
8. With the aforesaid changes taking place during the DSZ process, there is improvement in the tool life, which has been experienced by number of researchers.
DEEP SUB ZERO PROCESSING OF METALS AND ALLOYS – PART II EVOLUTION OF MICROSTRUCTURE OF AISI T42 TOOL STEEL, C.L.Gogte1 , Kumar M. Iyer 2, R.K.Paretkar1, D.R.Peshwe1
1. Department of Metallurgical and Materials Engineering, VNIT, Nagpur, Maharashtra, India.
2. Assab Sripad Steels Ltd., Chennai, India


6. Modification of Carbide Population

In summary, cryogenic treatment cannot only facilitate the carbide formation and increase the carbide population and volume fraction in the matensite matrix, but can also make the carbide distribution more homogeneous. Our results are consistent with previous studies that show increases in carbide density and volume fraction, which may be responsible for the improvement in wear resistance.
Microstructure of cryogenic treated M2 tool steel. J. Y. Huang, Y. T. Zhu, X. Z. Liao, I. J. Beyerlein, M. A. Bourke, T. E. Mitchell: Materials Science and Technlogy Division, Los Alamos National Laboratory, MS G 755, Los Alamos, NM 87545. Publishe in Materials Science and Engineering A339 (2003) pages 241-244

7. Copper Welding Electrodes Last Longer

Cryogenic treatment of copper welding resistance electrodes increases their life by a factor 2 to 9 . Both durability and conductivity were increased although the mechanisms behind the improvement are being further researched. Metallurgists suspect that stress relaxation through recrystallization is responsible for the property improvement.
Sub-zero Treatment of Steels Technology/Processes/Equipment, Linde AG | Linde Gas Division | 82049 Höllriegelskreuth | Germany

 

[Nathan the Machinist]

it only proves that you hang around with the wrong sort of people and that you are therefore also suspect.

That statement doesn't even make any sense. :thumbdn:



I am not the cryo salesman here making extraordinary claims. I am one of many people here who have tried cryo (controlled cool down, long soak, controlled return to ambient - not just a "dunk") and I have seen first hand that its utility in knives is best utilized as part of a quench and that no special properties can be expected on an already finished blade. I have tried it Rick, and I don't think it works. If you would like, send me an email with your shipping address and I will send you two finished D2 blades. One with RA, one without. I have control blades here. You can treat them and return them and I will evaluate them. I am an honest person with no problem admitting if I'm wrong and I give my word I'll be objective.

We are pragmatic, results oriented people here.

 

[Troop]

Warbird,
Let me just put this out to you, for whatever it's worth.
Nobody around here knows you. As far as we know, you could be some guy with an overactive imagination.
You need to develop trust, if any of us is going to take you seriously. Assuming, of course, that you're interested in any of us taking you seriously.
Conversely, Nathan and Mete (and many others) have developed trust with us over the years. Most, if not all, of us have verified the knowledge that they have shared with us, at least in part, in our own shops.
We're a pretty tight-knit group, and our trust doesn't come easily.

- Mitch

 

[warbird436]

Nathan:

If you are trying to eliminate retained austenite, you are correct that the process is best done quickly after quenching. But if all you are doing is trying to reduce retained austenite, you can do that at -140F with cold treating. The research I have read indicates that the martensitic transformation is about done at that point. The research also indicates that there is a change in the martensite created by cryogenic processing.

My claims may sound extraordinary, but as you can see, they are backed with the study of the research that I take a lot of trouble to find. Yes, I have seen some silly claims in the industry. I use them in my lectures to point out that the process needs real research. One was that "Nobody has ever blown up a cryogenically treated engine." Nuts, racers can break anything. Another was that the process increased the strength of steel by a factor of ten. But I have also seen some things actually take place that were extraordinary. For instance time after time when we do granulator blades we get huge increases in life, on the order of eight times that of an untreated blade.

I will be happy to process some blades for you, but first we have to establish what you are trying to achieve. One man's blade is another's club. (Reference broad swords that were used to break through armor rather than cut a body like a katana, or the difference between a sabre and an epee.) So contact me and let's see what is up.


Troop:
I appreciate your post.

The problem here is that this group sets itself up as experts and then makes disparaging remarks about something they really have not researched. People come and read these forums and decide that cryogenic processing is not a valid process based on these "experts". I actually don't care whether you fellows trust me or not. I do care that people who are looking for information about cryogenic processing get an accurate picture based on facts and research. I did not see that here. If you fellows want to continue with a discussion based on science and reallity, I will probably be able to spend some time here.

 

[cotdt]

The industry mostly uses tests for types of wear not useful to knife edges, ie. adhesive wear. We know about the carbide refinement that deep cryo gives, but 8x improvement in wear in drills and punches doesn't impress. It simply does not carry over to knives in the same magnitude, none of the knifemakers I know have detected any benefits whatsoever other than converting retained RA.

 

[nullack]

Codtd my friend, I think its fair to say that knife tribology is not scientifically understood. However, I would not reject adhesive wear as not occuring at all though. Sure abrasive wear is more common, along with corrosive wear, but I have in fact observed adhesive wear in knife tests I've conducted. I'm fully open in saying that the adhesive wear occured in using a test blade in ways that would not be common but for sure it does occur.

 

[cotdt]

Codtd my friend, I think its fair to say that knife tribology is not scientifically understood. However, I would not reject adhesive wear as not occuring at all though. Sure abrasive wear is more common, along with corrosive wear, but I have in fact observed adhesive wear in knife tests I've conducted. I'm fully open in saying that the adhesive wear occured in using a test blade in ways that would not be common but for sure it does occur.

Good points. I would imagine that adhesive wear would start taking effect if you cut really hard objects. What do you think about the data in ASM Metals Handbook - Heat Treating, page 490? That's a huge increase in abrasive wear resistance, but the numbers look unreal.