Deep freeze method

[Maniac]

I was reading an issue of Hot Rod today in school, (Junkyard Jewels, issue before the newest one I think) and they were showing how the NHRA uses the method of deep freezing engine blocks in order to increase the life of them, and to help newly added metal to bond with the block better. It said NASA was using this in the 60's with around -120 degress or something, and now they use Lidquid Nitrogen gases to drop the temperature to 300 degrees below. This sounds like an interesting technique, I wonder if any shops could offer this, since the process only takes a complete day I think.

[Maniac]

I was reading an issue of Hot Rod today in school, (Junkyard Jewels, issue before the newest one I think) and they were showing how the NHRA uses the method of deep freezing engine blocks in order to increase the life of them, and to help newly added metal to bond with the block better. It said NASA was using this in the 60's with around -120 degress or something, and now they use Lidquid Nitrogen gases to drop the temperature to 300 degrees below. This sounds like an interesting technique, I wonder if any shops could offer this, since the process only takes a complete day I think.

[Scott Misus]

Why would NHRA have any interest in deep freezing blocks?

[David Holmberg]

TNN did a story on that last year, It seems that All/most of the nascar teams are using the process for motor parts. As I remember it went from intense heat to a freeze condition and cycles for a set time. The high heat and cold made the structure of the metals form better and more even. The equipment was cool, No pun intended!

[Bob Dillon]

Hmmm, maybe all that liquid nitrogen is
why the good ol' boys talk so funny....

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I want to die peacefully
in my sleep like my grandpa,
not screaming like the passengers
in his car.

[Steve C.]

NASCAR guys go nuts and they have the budget and R&D to do it! This process is probably effecting the mollecular structure of the metal for stronger & longer life similar to heat treating(?). They fiddle with all kinds of stuff. Even been known to heat up blocks and subject them to stresses while doing the machine work.... were talkin' stresses beyond a typical torque plate.

[WARPed]

Couldn't this be seen as a form of seasoning of the virgin metal? Kind of like getting things to "settle" before they do any machining?

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10.854@123.44
6.947@100.65
brooksa@gte.net

[Robert J. Ardoin]

Cryo treating has been used by the Japs for a while now makes cutting tools last longer, even the major gun barrel maker are in to Cryo treatments. Supposly makes every thing stronger and more uniform. 10%-20% stronger, also more slicker kind alike chrome,it is so hard it becomes slipper. Cajundog

[Vascar]

Many HiPo shops around the country knows where or who to call for cryo tempering. The cost of the process is around 600 to 700 for a complete engine in most places. I have heard of cheaper, but you have to wonder. If you chose to do just the heads and crank you will get charged by weight, it's cheaper to do the whole engine. You will feel the cost and you won't see anything done to the parts. It makes you wonder because "you can't see anything done". It's a hidden benefit. Everything will last longer and you will have a more stable engine.
Some will kick the dirt and say "well, I can't see why you would need to do this, after all, it's not a Nascar engine". Comes down to this; "if you want a longer lasting engine and a little better performer, cryogenics will help".

[Gach]

I have blocks done, When you get the block back, it looks like a bran new block,
even in the water jackets, there is no rust what so ever, really unbelievable. The heads I've cut up, for port work, inside look like a new head.

[Tom Hand]

I have a friend here in KC that owns a cryogenic treatment business. I can have him mail literature to you if you send me a mailing address. It might take me a few days to contact him but I will be glad to do it.
Tom Hand

[This message has been edited by Tom Hand (edited 02-12-2000).]

[Gach]

Thanks Tom, I would really appreciated.

[Pete D]

May I have a copy of the cryo info too?

[Tom Hand]

http://www.performancemarket.com/coatings.htm

For additional information, go to this site. My friend runs Tech Spec in KC, MO.
Tom Hand

[Roar]

Me to Tom if you can. ;-)

[Skip Fix]

From what I read the process compacts the molecules(molecules slow down and the "shells between their electrons" get a little closer the colder they get. The "thawing" process is the trick , done correctlt it keeps the molecules in a more linear grain pattern which makes the metal stronger. The Briggs go cart racers have had their cranks done for years.

Skip

[Tom Hand]

I wanted you all to know that I called my friend to see if he emailed out some info but unfortunately, he has been ill, He will be sending out some info tomorrow or the next day. Please be patient as he sounded pretty bad when I called him! (Flu)
Tom Hand

[Tom Hand]

For some more info, this month's Machine Design magazine has an article about cryogenic treatment. Go to www.machinedesign.com, (http://www.machinedesign.com,) February 24, page 67.
Tom Hand

[percryo]

Manaic, Yes there are a lot of race teams Nascar, SCCA, NHRA, AHDRA, ADBA and many others are using cryogenics to get better performance out of there engines, drive trains and brakes. During the past couple of years there has been some very large steps in the cryogenic field, no longer can you just submit a component to extreem cold and get the optium enhancement. Custom Thermal Cycling (cryogenics) is know computer controled with vering peramiters for verious components, no longer is it a one cookie cutter operation. The amount of treatment time necessary is also dependant on the componants size, type of metal and the desired result. Our web site www.percryo.com (http://www.percryo.com) has some cryo 101 info perhaps it may interest you and while you are there enjoy the pictures and please sign the guest book. I think you may find the article on kart engine performance improvement also interesting. If yo have any question please Email via the web site. Thank you. percryo.

[LarryF]

Does it remove stains, too? While some of the claims of the companies that do cryogenic treatments are true, it isn't a universal process that will make everything under the sun better, stronger, faster, etc.

Cryogenic tempering has been used for years in the machine tool industry to "finish what heat treating started," to quote one of the cryo websites. What it does is really pretty simple. When steel is heat treated to make it harder and stronger, it is first heated to a high temperature, where it's structure changes to Austenite, which is a soft form of steel (it normally exists only at high temperatures, but 304 stainless is an example of room temperature austenitic steel). When the hot steel is quenched in water, oil or air, depending on the alloy, it then changes to Martensite, which is very hard and brittle. A small amount of Austenite may remain mixed in the martensite after quenching, which is where cryo tempering comes in.

The next step is normally to temper the martensitic steel at a medium temperature (usually less than 1000 degrees F) to make it tougher and less brittle. If the part is then put to use, any austenite that still remains (called retained austenite) leaves microscopic soft spots that wear and fatigue easily. It can also later transform to martensite, which will be brittle. This can cause microscopic cracking and high stresses, which can reduce the fatigue strength of the part.

The solution is to cryogenically cool the part, preferably before tempering, to force all of the austenite to transform to martensite. Then, when the part is tempered the microstructure will be consistent.

Retained austenite is usually only a problem in highly alloyed steel, like tool steels and maybe something like 4340, although this is questionable. Retained austenite is unique to steel and maybe some heat treated cast irons, so it won't be found in other metals, like aluminum.

Some claim that cryo tempering relieves residual stresses in other metals, like brass. Since residual (internal) stress is very difficult to measure and takes the kind of equipment that is usually only found in government research labs, there is no easy way to prove or disprove the claims. In metallurgical terms, though, residual stress is relieved by allowing the atoms that make up the metal to relocate slightly (think of it as settling in and relaxing). To allow things to move takes higher temperature, not lower temperature, so I think the claims of relieving residual stress (in metals other than martensitic steel) are highly suspect.

If it was my money, I wouldn't waste it on cryo treating anything other than maybe some highly stressed, heat treated steel components, like rods, valve springs, wrist pins, etc. Even then, it would be best to have it done before these parts are tempered when they are manufactured. I wouldn't bother with blocks, pistons, and other cast or moderate strength parts, especially those that are not heat treated to begin with. It certainly has it's place as long as you understand what the process is capable of doing.


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Larry

'63 421SD LeMans...
in pieces in my garage
and basement