Cryogenic Tempering

Whats some of your opinions on doing this to a cast crack. This came up in another forum and here was one response.

Ran it in his pro street race nova (8sec) 1000HP + 18 deg 406SBC with NOS
for years. COuple rebuilds, couple smashed pistons, tons of runs. The bearing journals always looked like new on teardown. Crank never broke.

The cost to cryogenically temper a cast crank costs a little less than $200.

I read somewhere that cryogenic treatment did not have a beneficial effect on cast iron or low-carbon steel.

Can you elaborate on your response? What exactly was said? There must have been some scientific explanation for this. Here is a quote from Diversified Cryogenics.

Deep cryogenic processing creates a large amount of fine or small carbides that precipitate uniformly throughout the lattice structure. This greatly improves the wear properties of metal. The process also completes the martensitic phase change which creates a metallurgically improved and stabilized alloy.

From everything I have read its says the opposite and that it helps resist wear. But I will try and get additional information about low carbon steel and cast iron in all fairness.

I contacted one of the cryogenic service sites and this is what I got back.

We can improve the wearability and toughness of almost any metal. The percentage of increase is determined by the alloy of the metal and it's carbon content and how and if it was heat treated.

How low a carbon content?
What specific alloys are you interested in? Most of our business currently is Grey cast iron (Brake Rotors). They last better than double from a wear standpoint and I have yet to see them warp after processing 200,000 plus rotors.


Bill Groschen

I contacted one of the cryogenic service sites and this is what I got back.
Sounds like Praise Dyno Brakes (http://www.praisedynobrake.com/) might be one of their customers. They claim to be able to lower the braking distance of drum brakes by about 25% by cryogenically treating the drums and using special ceramic pads. I initially came very close to putting these on my car and still may. It came down to ****$ and time, but it wasn't an issue with product quality. It still sounds like great stuff.

http://www.hotrodders.com/forum/cryogenics-8451.html?highlight=cryo has some discussion of cryo treatment. I tried to find the page where I saw the statement that it didn't affect iron or low-carbon steel, but it looks like that page does not exist any more. Shilen now says it won't hurt a gun barrel, but it won't help it either, as far as stress relief ( www.shilen.com , FAQ #1). They didn't say anything about wear characteristics.

I took up the offer from "Cryomotorsports" about the free razor (in June of 2003), and although I only shave my upper cheeks & lower neck, and only a couple of times a week, I'm still shaving with that razor, although it has been dragging a bit for the last few weeks.

Google cryogenic+steel+Barron & you can read up on it.

I have access to a cryogenic freezer thats capable of freezing down to -196c and has a digital control to lower and raise the temperature at a timed 1 degree increments. The freezer is large enough to temper a whole engine. I have access and know the owner of a major chemical developmental lab. I have found some detailed information on how it is done.

The material is slowly cooled to -
320F (-196C) and "soaked" at that deep cryogenic temperature for
20-40 hours. The material is then allowed to return very slowly
to ambient temperature. The complete cryogenic cycle can take up
to 72 hours to complete. This procedure of precisely controlled
temperature profiles avoids any possibility of thermal shock and
thermal stress that is experienced when a tool or part is
subjected to abrupt or extreme temperature changes.

Do you think it can be done and would anyone have any added info?

I can't offer any additional detail on whether your plan is do-able or beneficial, but I can provide you with the name of a company who is doing exactly that process (or very similar) to a variety or metallic objects.

http://www.praisedynobrake.com/cryogenic.htm

I really considered using their drum braking system on my car. They claim it adds an additional 30% braking power to an OEM drum setup.

I'd hate to ask what they'd charge to do an entire engine block. :eek: ;)

These guys charge $600 for a complete engine

http://www.onecryo.com/onecryo/

I actually could have had my own cryo freezer but I just found out about this process as of recently. The company had thrown out a old working cryo freezer about a year ago so I missed out.

I have access to a cryogenic freezer thats capable of freezing down to -1000f and has a digital control to lower and raise the temperature at a timed 1 degree increments. The freezer is large enough to temper a whole engine.

Sorry...I couldn't help myself. :D

http://i29.photobucket.com/albums/c296/Mad4Morgans/CyrogenicFreezingFacility.jpg

The cryogenic freezer they have runs on liquid nitrogen but would probably freeze ice cream very well.:)

couldn't ya ask Ol' Ted Williams ta hook ya up ??? :D :D :D

I had some questions but reading the website posted above answered some of them except concerning this remark where it said:

"Researchers have found that the effects of shallow cryogenic tempering (-110°F) is minimal unless it is performed as part of the initial heat treat cycle."

Since your talking materials after the initial heat treat cycle has been finished, does deep cryogenic (-196C) tempering somehow differ from that observation?

Is this a process that can be done after the fact or do you have to heat up the metals to start the process over again?

This question came up once before but I can't find the thread. I once asked our chief engineer about it and he said the same thing. It has to be done in the manufacturing process. After the fact has little value. Some parts benefit from it and others don't depending on material, usage etc.

I had the block, and the rods done on my Buick. It was done on the reccomendation of the engine builder, a very reputable guy that had nothing to gain by having the parts frozen, other than helping his rep if the engine stays together;)

I am running stock rods near their maximum potential and Buick blocks are pretty light. They are good for 550hp in stock form, above that they require a girdle on the bottom end. The cryo process was a little extra insurance, and much less expensive than the machine work required to do the girdle.

I had it done several times on brake rotors and can definately say it helps there. I was running Porsches on a road course which is brutal on brakes. The cryo treated rotors lasted twice as long as the same rotors that had not been frozen, so four weekends instead of two:rolleyes: