Cryogenic Technical Articles Options

[lmcchesney]

I have reviewed all the messages from the foum regarding cryogenic processing of engine parts. However, it lacks good/significant documentation regarding the different processes done.
Does anyone know the source of technical articles regarding this process.
There must be some University site with this information.
Yes, I have searched the MIT site without success.
Anyone have the information?
Thanks,
L. McChesney

[kdfoust]

It wouldn't surprise me if the legitimately developed and tested methods are held as trade secrets. As you say, university research may be the best source of information. I'll talk to some people and let you know if I find any leads that have actual test data to back up the claims.

Are you planning to DO IT, or USE it? Have you called some local heat treatment shops and asked them about it?


***********here's a nugget of nfo for you***************
A quick patent search yielded this as a hit. Note the austenite decrease claim.

Patent Assignee: INST STIINT ING TEH
Inventors: BUMBEA E; DRUGA L; FRANCISC V; GIACOMELLI I; MUNTEANU A; PANTEA V; TEACA M; VASILIU A
Patent Family Patent Number Kind Date Application Number Kind Date Week Type
RO 92459 A 19870930 RO 119206 A 19870619 198804 B

Priority Applications (Number Kind Date): RO 119206 A ( 19850619); RO 119206 A ( 19870619)

Abstract:
RO 92459 A

The process comprises nitriding or carbonitriding to give a 0.05-0.15 mm hardened layer. Thus thread rolling jaws and other cold plastic deformation tool can be hardened in this way.

The heating is followed by sub-zero treatment to decrease the residual austenite content to below 5%.

ADVANTAGE - The process increases cold working tool quality.

[kdfoust]

Wear \"Chilled Out\" of Stamping Dies & Punches

Cryogenic Tempering Extends Part and Tool Life

Cryogenic Process Improves Engine, Brake Life
I found a patent to go with the above link: US 20020179204


[/URL]Thiokol to Use Cryogenic Tempering Technology

[Mark Henry]

My first reaction to cryo was "snake oil". But heat-treating is almost cryo in reverse so maybe it has some merit. In doing the little bit of research that I have done I couldn't find any hard data that came from "independent" sources. So for now I'm keeping an open mind but I find the claims dubious at best.

I know Jake swears by cryo and I respect his opnion, but again he's not what I call "independent" from the cryo industry.

kdfoust said:
"It wouldn't surprise me if the legitimately developed and tested methods are held as trade secrets."

The process is a trade secret but the end result should not be, what's the rockwell hardness before/ after, etc.

An interesting article came from a woodworking tool catalogue that I just received last week. Veritas tools are made by Lee Valley, high quality and costly, sort of the Snap-on of woodworking tools. I know it may not directly relate to engine parts, but it was interesting to see.

[Jake Raby]

One day I was in my ocal Barber shop... My regular guy was on vacation so I went to some chick... well.

About the time I'm about to fal asleep in the chair the "Scissor shaprenin guy" comes in... He takes a ton of scissors from everyone in the place except the chick cutting my hair. He asks her "So why haven't you needed your shears sharpened in the last year?"

She comes bback with "My husband froze them" and then the conversation began... Come to find out her husband "Freezes" almost every engine in the NASCAR field.... I did not believe it till he froze the engine parts for my bus and I went over 15K miles without touching a valve for an adjustment....


I'm independant in the cryo industry... I don't own one cryo tool but have helped to perfect 31 cryo profiles for my engine components.....

[ArtechnikA]

it's pretty well thought of in the rifle barrel industry.

think about this: why would we believe the effects of heat-treating stop at room temperature just because that's a comfortable environment for humans ? the theory, as i've heard it explained, is that the heat-treat chemical process in the steel continues right down approaching absolute zero.

i have seen before/after tests on gun barrel accuracy in which residual stresses produced 'stringing' (asymetrical thermal expansion causing barrel curvature and a 'string' (line) of hits) that wa eliminated following cryo treatment.

i know some people who claim wonderful effects in aluminum alloy, but as that does not have the austenite/martensite bi-phase thing, i'm skeptical there. but i haven't seen any 'before and after' product tests either, so i donno.

i know life extension is claimed for brake rotors, but since it seems to double life at double the cost, i'd think it beneficial mostly to endurance racers who could potentially avoid a mid-race rotor swap and gain a competitive advantage.

for other parts - connecting rods ? crankshafts ? camshafts ? i s'pose it couldn't hoit, especially if there were a friction reduction. my water-VW camshafts have shown no visible lobe wear after 350,000 mi so i hope it has a more compelling reason than just wear reduction. OTOH - those cams may have had an expensive surface treatment that costs more than cryo would. i'm no metallurgist, i just know what i read ...

[airsix]

Cryo treatment is common as part of the heat-treatment of several carbon and stainless tool steels. When heat treating steel it is taken to a specific temp where it undergoes a molecular change to a state called austenite. The steel is then 'quenched' to quickly reduce it's temperature. Quenching changes the steel to a state called martensite (assuming everything went according to plan). Some steel has molecules that tend to linger and may not fully convert to martensite, but instead end up as something else like pearlite. Cryo treatment of certain steels can get some of these lingering molecules transformed to martensite. The result is more uniform grain and hardness. Cryo treatment of certain stainless tool steels can increase hardness after heat treat by one or two points on the Rockwell C scale. I don't know what legitimate benefits can be had from cryo treatement of metals that are not being subjected to a heat-treating/hardening process. When I hear about iron brake rotors and the like being cryo treated I tend to raise and eyebrow. Sounds like snakeoil (but I could be wrong).

-Ben M.

[airsix]

Rich,
Your comments about gun barrel stress are interesting. Cryo treatment actually can increase stresses. You can actually fracture some hardened tool steels durring cryo treatment if they haven't gone through a tempering (moderate heating - usually something like 500-650 degrees F for a regulated period) cycle first to releave internal stresses. I bet these gun barels are going through several preperatory steps before and possibly after the cryo treatment. Interesting stuff.

-Ben

[kdfoust]

To me the discussion is not around "the whether" or "the how" of it working in one application. The important discussion is around practical significance. I'm reasonably certain that structural changes are manifested in materials through cryo treament processes. The question is: "does it matter?"

The cryo rotor application is an easy target for the "who cares" sort of argument.

Substantial test data is lacking to say the least. Ancedotal evidence...well "in god we trust, every one else bring data."

[lmcchesney]

The concept is intriging but the lack of data is worrisome.
I can understand that each company can develop their proprietary methods to achieve a desired result. This provides for a market advantage. However, it also provides no assurance to the consumer as to what company method is successful.
There also has to be ranges of successful methods. Rember, our fathers/uncles placed their crankshafts out at night. DD reminded us of the serindupitous finding of the results of metal objects returning from space.
I have some experience with cyopreservation and destruction of cells. Some time ago, to control the nucleation step required an expinsive equiptment for the step wise cooling and freezing of cells. Creative research techs found that they could approximate, not match, but approximate the same process using a alcohol bath and step wise use of the refrig, freezer, gas phase N2 and then Liquid N2. Same way with the thawing fo the cells.
I continue to seek the .edu sites in hope to find a grad students thesis.

L. McChesney

[Jake Raby]

I talked to my cryo guy- he'll be here later..

[Targa]

I plan on incorperating this process into my engine rebuild. I found ONE guy in the bay area that will treat parts, engines, etc. The proof I will be looking for will be in lower head temps, lower oil temps, life of valve adjustments, life of engine. It will be an ongoing test until I need another rebuild which I won't plan on for a hundred thousand miles or so.

[Dave_Darling]

So far, the evidence that I have seen is all anecdotal. The bit about treated parts having harder Rockwell numbers is new to me, and very intriguing. It could easily lead to the sort of info that could convince me...

Some of the folks on the Racing Rennlist email list tried cryo'd brake rotors. The one application I remember was on a 944 (over 3,000 lbs in racing trim) and the owner found zero difference in the stopping power or life span of the cryo'd rotors versus the plain untreated ones.

At the very least, this says to me that the treatment is sensitive about its application or about how it is applied. It would be helpful to have a way to verify that whatever good things are supposed to happen inside the metal actually did...

I have also heard one metallurgist opine that "even if it did anything, the effects would be lost the first time you heat-cycled it." I think he was talking about rotors again, though. Engines are obviously at least a bit different.

--DD

[TimT]

even if it did anything, the effects would be lost the first time you heat-cycled it

Everytime you run your engine you heat cycle it..

I know a bit about metalurgy (far from an expert but AWS, ASTM etc seem to think Im ok) Most of the changes in the crystal structure take place when the metal is cooling from a liquid to a solid state... then there are various holds where metals lose the various ferrites ie austentite, martensite etc....

I did alot of searching a few years ago regarding the merits of cryo...... like Dave said alot of anecdotal claims..... no hard #'s..

Having said that I doubt I cryo my $100 rotors

I might freeze my crank though...

Alot of succesful race teams use it....

[Mark Henry]

I talked to my cryo guy- he'll be here later..

Do you honestly think he will have anything but positive things to say about cryo?

"I'm independent in the cryo industry... I don't own one cryo tool but have helped to perfect 31 cryo profiles for my engine components..... "

Do you make any money when you (have them) cyro a customers part? If you do, then how can you call yourself independent?

I know a shop down the road that sold and used slick50 "independently" for years, when the government told slick50 to stop making their claims he stopped using it. He found no difference, he now thinks that he had been selling snake oil all that time.


What I think is being asked here is for hard scientific proof from a lab that is independent from the cryo industry.

[Dave_Darling]

Everytime you run your engine you heat cycle it..

Yes, but the cycle is different. Rotors, for instance, will see much higher temps than a crankshaft will.

--DD

[airsix]

Dave,
You might like reading some of the info Crucible publishes regarding their products. They pretty much lead the industry (IMHO) when it comes to steel technology.

Here is a link to a very basic overview of some heat-treat steps for tool-steels (in general - not specific) that includes some basic info on the role of cryo treatment in the hardening process. When I said that the cryo treatment could increase the hardness of a steel I mean specific to the heat-treat process. The benefit is in getting some of the more stuborn tool steels to more fully transform austenite to martensite. And you only get austenite when you take the steel to critical temp (as high as 2,100 F for some steels). If you cryo any old piece of anealed (non hardened) steel that's just laying around, the cryo will have no effect on hardness as far as I know.

Elsewhere on crucible's site they have whitepapers with specs on each of their steels with specific heat-treat proceedures for each including hardness tables for different heat-treat procedures including cryo and non-cryo treatments.

-Ben M.

[Jake Raby]

I am INDEPENDANT!

Want to see how??
When my parts are cryoed it means that they need the parts for atleast 1.5 weeks to do their processes..

That affects turnaround time on the entire engine. It als means that I have to do all the work, and mock up/balance the assembly before they pick up the parts for the service. It also means that I have to inventory all the stuff and box it all up for transport.

The standard cryo process for an entire engine cost me 475.00 it cost my customer 500.00 as an inclusion in the process of the build. So for 25.00 I spend all the time to have the parts processed, pack them up and go through those hassles.

I have to for instance buy valve seats, send them out for the process and then have the seats sent back to the head shop for installation since the entire head should not be treated when it is assembled (expansion issues between aluminum and seat material)

I easily LOSE money on the process, and maybe break even. What it does do is give my engines another edge over the rest and keeps my reputation wher its at and has been. Thats more important than a 10 million dollar check!

I have NEVER seen a failure using cryoed parts with the guys that do my work.... I can say that I have seen a broken (cracked 3/4 way through the center main)crankshaft purposely installed into bus engine and driven 10K and it never broke... (don't ask why)

Please don't imply that something does not work until you experience it yourself. It takes risks to find out what works and what don't I take those risks with my test engines and have yet to see a problem with any cryo process. I doubted the cryo process just as much as many of you do here, BUT I can say it has proven its self to me and many others that have been able to directly compare the results we have seen with it against parts that were not treated.

My lab is called a dyno cell.... I'm not a metallurgist and don't care how/why it works.. I just know that I like the results and use the process.

[ArtechnikA]

<bunch of irrelevant stuff snipped...>

...BUT I can say it has proven its self to me...

i think all we're asking is HOW has it proven itself ?

"parts didn't fail" - sorry - that's very nice, but it doesn't prove a thing.

have you run tests like cryo'ing half the lifters in an engine and then checking for wear ?
the valve seats on one side of the engine but not the other ?

(don't get me wrong - i actually -do- believe it's helpful, i'm just trying to clarify the question.)

what physical comparison tests have you done to verify the difference between a treated and untreated part ?

the arm-waving part about costs has nothing to do with independence, or metals properties, BTW.
you could just as easily say it's expensive and time-consuming for you to paint every part blue. okay, it's time-consuming and expensive, but how do you know the parts are any better for having done it ?

[JmuRiz]

I see it as a parts don't wear out as fast issue. That's good enough for me. A test on 1/2 of the lifters/cyls etc treated and the other 1/2 not would be good. Granted it'd take time and $ to do such a test.

If people had not experimented with heat treating and rapidly cooling we'd still be in the bronze age or w/ crappy steel that breaks. Must be something to it if the (NASCAR) racers do it...I'd like to see if the Porsche factory guys as well as sportscar/F1 cars do it (especially with the new longevity rules in F1 this year).