Cheesy

No it is not cold working, its closer to an aging process that you would use in a solution treatable aluminium. Cryo treatment does work for some applications and this is documented, namely transforming retained austenite to martensite in some tool steels, this transformation is not diffusion controlled so only the martensite start temp is important, however because of the difference in volume during the initial austenite to martensite transformation there will be stress fields in the material which will change the martensite start temperature. Incidentally most phase diagrams are for atmospheric pressure, the eutectic points can change depending on pressure. I agree with you on the break rotors and things like that, I have seen no info on that

Mr. Midas

This is quite a discussion.

I really appreciate all the feedback and time everyone has spent to discuss this.

Cheers!, thanks for the input. I'll see if I can look into those specs some more. Much of everyone's info seems to be going over my head right now. (I'll reread when i'm not as tired)

In some of your posts you referred to cryo treatment as dunking a part into the liquid gas. None of the companies I've researched describe their process as dunking parts into a liquid gas; rather, most of them claim to have some process of gradually lowering the temperature to the target temp, holding the piece at the target temp for a period of time, and then gradually bring the piece back to room temp. I think every one claimed the process does convert retained austenite to martensite.



Yes, most of the information I was able to find was from the various cryo companies, so you have to sift through their claims and see if they are just sales hype or real information. Just because there are so many cryo treaters out there does not mean it is a proven process, and the great lack of information does make it suspicious. Are these companies just hoping the customers will believe it made a difference and continue to do business with them? After reading testimonials(not posted by the cryo company) of people who found an increase of life span from (a) part(s) they had cryo treated, I have to believe(for now) that there is some validity to cryo treating.



When I have more time I might post some links that I found with some more in-depth info. I'd rather not be a repeater, and I don't think many people appreciate it either. Much of what I found is there for anyone to see via google. I wish I had more hands-on experience, but that's the consequence of being young.



About the wood/metal comparison...

I only meant to compare how I could buy one of a cryo company's claims of how metal instruments could be improved by relieving more of their internal stress, as I am familiar with the affects of the built-in stresses of wood and how it can greatly reduce the quality of sound when used in an instrument. I wasn't thinking about wood/metal per se; just the path of sound waves passing through or resonating from something with more or less internal stress.

I sometimes oddly, wrongly, or oddly and wrongly word things in an attempt to relay my ideas, or run-on with residual thoughts remotely related to the subject of my idea, as an outcome, I may be taken to say, or even truly say something that is odd, wrong, or odd and wrong. I apologize.





Well, I need to go get some rest before it gets too late(already is. lol). I'll be spending the whole day, from sun up to who knows when, helping pour and finish 65 cubic yards of wonderful crystalline matrix forming concrete...

Cheers!

In conventional heat threatments If you convert austenite to martinsite you get dimensional changes (ie warping). Now with brake rotors you can remove enough material to make it run true again. If cryo treatments do in fact change austinite to martinsite (no proof as yet, as I can not find anything that is documented from any one or any organization with creditability) how are you going to machine the teeth of the stationary gear so that it is within mazda's tolerance again?



When I refer to cryotreatments i use the term "dunk" since you need to take a part to the temperature of liquid nitrogen and ensure it is homegenous throughout the peice. Even if you rig up a fancy chamber and start to feed in liquid nitrogen to control the rate of cool you will need to eventually fully submerge the peice to ensure the entire peice has reached liquid nitrogen's temperature.



So what temperatures do they do cryotreatments? Do they have the dwell time at liquid nitrogen temps or at liquid helium's temperature?



Newguy707: For the price of cryotreating process, why don't you just buy racing beat hardened gears? or FD gears? or rx8 gears? They aren't that expensive, and are already proven to work.

Cheers!

;j

Lynn E. Hanover

Skeptical should be the minimum.



When a factoid shows up that seems to violate common sense, just smile and listen. I thought I had been the most lucky man alive because of all of the advances that had been made while I was here. I was wrong.



Improved communications and the home computer have bent the learning curve upwards at a steep angle.



The cryo thing is just taking off. Big companies don't buy this equipment if there is nothing to it. There are thousands of specs and standards that we can never see, because the intel people can tell what you are working on by obtaining just a few of them.



The rustbelt spec holders have none of them because the security stamp is higher than any document control spec compliance they could meet. Far more than I have seen for sensitive and NOFORN. If you were involved in a project you can only get a spec through supervision and a document officer who will determin if you need to see that document. You would not say a word about any spec or standard that you have seen.



When you sit in on a meeting where you have a little scrap of the pony show, listen to all of it. I often was able to piece togther a much bigger part of the picture than I was supposed to know about.



There are now specifications for the cooking up of Nanotubes and Buckey *****. Less than 10 years after being discovered, you can buy kilogram quantities of this stuff from a number of manufactures. Those documents that AMSE or SAE will use to write anything they will, must come from the industry that has the knowledge about it. The industry is not in the mood to do any such thing for competition reasons. So the rust belt spec holders may not see anything for some time after the fact. If the government needs to have "In process" inspection of the newer stuff, then only those documents provided by the manufacturer will be available. Unless the government buys the data, the government cannot remove any data from the inspection area.



The cryo stuff may not perform as advertised by those touting it for their own gain.



The number of really smart people and corperations useing it would seem to indicate otherwise.



The profound effect that seemingly modest cold has on some alloys, leads me to think that a more permanent change could be had at much deeper temps, held for a week or so. The room temperature idea is

just a point on a chart to metals. Metals continue to change shape and suffer measurable changes all along the temp scale.



Twenty five years ago if I told you that I had developed a metal with a shape memory, that could be triggered by the temperature change generated by the radiant heat from your hand, what would you say?



There are no specs for it? It cannot be so?



Now you can buy it. You can make a motor that turns a generator that runs because one half of a motor is exposed to the sun while half is shaded. Direct conversion of sunlight to work. A statment so outlandish then, that nobody would believe it. And here we are now and it is common as dirt.



A whole new (high tech) industry is being developed around soot from smoke stacks. Petroleum engineers have been studying soot since just after dirt was discovered. How did all of those people miss carbon 60 and carbon70? (Soot is used in rubber products like tires to add strength and wear resistance)



The first peer review the boys got back after they published on the carbon 60/70 find was from Bell Labs.



Usually a few pages that refute or varify findings and suggestions for use. The Bell Labs engineers thought of a few uses for the strands with the strength of a diamond. Their review submission was as thick as a NYC phone directory. (And they did not send the really good stuff), if you could reduce the weight of the 25 ton wing spar in a 747 to 7 tons and reduce the cost of manufacture by 50%, would there be any advantage in that?



A few rears back, a teenager form a town just north of Columbus was making industrial diamonds in his garage. His process was so simple and so inexpensive as to be laughable. GE bought him out. How did all of the thousands of engineers around the world who worked on this daily not see this process?



Never say never.





Lynn E. Hanover

j9fd3s

one thing that science is not good at is that we think we know everything at any one given point, and is usually proven wrong. remember the earth was flat? we didnt orbit the sun, the sun orbited the earth? tobacco was thought to "clear the pores and release the vapors" in the 1600's, we thought dinosaurs moved slowly, betamax was a good idea, leg warmers.

Cheers!

I thought it still does!



anyhow, what good is cryotreating when I can't even determine the final increase in strength. I'm not talking abuot, hey lets just throw some brake rotors or stat gears in and make myself feel better that I did it instead of not doing it.



I'm talking about more general use of cryotreating, such as when someone has to design a new part from scratch. How can you design the part calling for processes that you don't even know the increase in performance. Atleast with heat treatments and traditional methods I know exactly what the recovered strength / increase in performance is.



I for one would not use cryotreatments, even if you did believe it increased the performance of the treated peice, how do you know by how much, how do you know piece A is the same as peice B that was reated the next day? You need to know the performance values of tensile strength, yeild strength, etc etc... in order to create you part with the necessary dimensions and calculated margin so that you can use cryotreatments to an advantage. If you said ya, we want you to design a new shaft for a chain sproket application, and we want you to use cryotreatments. The fact I can not find any hard evidence on the sucess or increase in performance after cryotreatments means I will design the shaft in a way that I assume cryotreatments do little to change anything, and make sure I have double or tripple the margin in the calcs just in case cryotreatments have negetive impacts on the metal.



Why would you use an unproven, undocumented, process with unknown results with the only thing you know is that on internet websites, discussion forums, and word of mouth telling you that "ya, my brake rotors or my crank shaft was treated, it's awesome, it's so much stronger". It's like buying live for ever magic water. Or listening to get rich quick schemes advertised in infomericals.



So how much stronger? Why can I not get a quantitative value for the material properties for anyone I ask, or how ever much research I do?

j9fd3s

yeah i agree with you, i'm not having any failures or unusual wear anyways

Cheesy

im deffinitly not an advocate of cryo treatments, but it has been proven and it is documented that it does transform 'retained austenite' to martensite. There is generally not a large volume of retained austenite so there is minimal dimensional changes, so it can sometimes be used to increase the dimensional stability of a component. Under high applied stress retained austenite can from 'burst martensite' which can be more brittle than plate or lathe martensite. So cryo treatment may not increase strength as such but could increase fracture toughness, which is potentially a better design parameter than yeild strength. The amount of retained austenite is entirely dependent on the alloy and previous heat treatments.

Lynn E. Hanover

The one feature I read about was extended life in shafting with splined ends where fatigue failures were propogating from the spline roots. Same for torsion bars.



I would get a list from one of the companies that does this stuff of their customers. The talk to engineers at those companies about what they expect from the process. See what testing they did. They may even provide you their test documentation and even samples. And if they have inhouse specs they may provide them. I used to be able to get samples of damn near anything, from anyone.



People are proud of their work and love to show of examples, provided your company is not a competitor.

People sent more **** to the government than Carter has liver pills. We had stacks of racing clutches and discs, when we were looking for a better clutch setup for the Chevy Blazer. When we got done testing them,

we gave them away. All too big for anything I needed.



See if one of the cryo companies has samples of bar stock, or whatever, that have been, and have not been cryo treated, for you to test.



Lynn E. Hanover