Cryo-genic treatment

[Tom Dunlap]

Has anyone used cryo treatment for any cutting tools?

If you aren't familiar with cryogenics, look here:

http://www.ln2cryo.com/index.html


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


I'm very familiar with the process but I wonder if anyone has actually used it for any of these arbo tools:

Sawchains

Saw bars

Chipper knives

Stump grinder teeth

Hand Saws

Spikes

Carabiners

Lowering devices

Hand pruners

Shaving blades

There are certain metals that have a good, proven and documented benefit from cryo. I asked an Oregon technician about the treatment and he did some research but told me that the alloys in saw chain wouldn't benefit from cryo. From a manufacturers price-point I can understand their point but I have access to the treatment at a pretty reasonable price: trade work.

 

[Walt Galer]

Howdy Tom,
I have crossed paths with cyrogenic heattreat twice. Once I used it to salvage a defective run of spur sprockets. The carburization operation and heattreat had left retained Austenite for a microstructure, and the parts were going to have to be scrapped. I borrowed a canister of liquid nitrogen from Simon Frazier University, and the plant saved the parts. The retained austenite completed transformation to martensite. This was essentially a high carbon steel (low alloy).

The second time was a special presentation fishing knife, done as a demonstration by the guys in the Metallurgy lab at Sandvik in Sweden. They used the material they use to make surgical instruments only cryrogenic processed to raise the rockwell hardness at least two points! The thing was so hard you cannot sharpen it on a steel. It stays sharp wonderfully, and is perfect for Salmon/Steelhead, and my very large rainbow trout.
This was high stainless.

Sawchain would not be expected to respond well because the Austempered structure should be bainite, and it is as resolved as possible. Only if the heattreat and/or material was defective, would there be retained austenite to resolve.

On the otherhand, a part made of a low carbon steel, might be made to respond to heattreat, where otherwise it would not. (As long as you did not get Pearlite).

A very high carbon part such as a spring can normally be toughened a fair bit by cyrogenic processing, since these are usually given a quick and dirty Martensite quench. The cold will assure a completly resolved structure.

Regards,
Walt Galer

 

[viking]

I have used gryo to solve certain application problems. Making cove blades for a loghome outfit out of D2 air hard tool steel to increase wear life. The cryo finished the complete hardening process and also increased the toughness so the blades did chip out in knots.
In die work the gryo fixes the complete heat treat. If you heat treat a pc. it will not complete it's transformation for some time and can result in the part growing as it does finish it's transformation. When you have only .0002 clearance this growth can be a problem. I would think it would have applications by allowing the use of harder steels that can take impact with out shatering. The cost of using these steels in production might not be justified because the market wouldn't stand the increased costs, but it has special situation applications

 

[kathicryo]

Cryogenics

Good morning,
My name is Kathi Bond, owner of CryoPlus in Wooster, Ohio. We have been cryo treating chipper knives, chain saw chains and bars for 12 years with some awesome results. Look at our web page under applications/logging and sawmill, www.cryoplus.com
If you have any questions, please feel free to contact me.

 

[Mange]

This was very interesting.

 

[Kenskip1]

Tom
Yes I have used this process on all of my cutlery. This process does what it claims. Only thing is to go for the -300 degree below. Some others only go to -170. Many fine knifes are treated with this process. Gerber, Ole Henry, and certain Sherade use this process. I will stick like epoxy to my beliefs. This process Works! Ken

 

[fwf]

It appears that there are two debates going on here.

1. Does cryo work?
2. Is it cost effective for saw chains?

Even if it does work, it's hard to imagine it being cost effective given the relatively short life and low cost of saw chains.

I could certainly see the potential value of cryo on a prized knife that is a long term investment, but it seems excessive for a saw chain unless you are into performance cutting where even a 1% improvement can make a difference.

 

[Tom Dunlap]

No doubt, the process works. But how is a value set?

For arbos I could possibly see a value for chipper knives. The catch is how is the value determined? Can anyone devise a test that would be credible? It would take many hours of use with and w/o cryo to set a baseline. Unless a company runs lots of chippers I don't see how all of the variable chipping conditions could be averaged.

A friend of mine has had things treated. The company that did the cryo showed the value for cutting edges by using razor blades and barber shears. Pretty convincing. But, saw chain and chipper knives are completely different metallurgy and use conditions. There is a possibility for handsaw blades though.

 

[BigUglySquirrel]

Cryo

I've heard some interesting tidbits about cryogenic-ally treating rotating assemblies (read: shortblock) in automobile engines. They reported an increase in lifespan of about 300%. (Toyota 4 and 6 cylinder passenger vehicles and one report of a private individual doing a Hybrid vehicle) Also reported DOUBLE the fuel efficiency. Toyota is rumored to be looking very hard at this type of technology as an OEM process. I understand the longevity increase...but fuel consumption? Someone care to take a stab at that angle? The reports were from a responsible source, but perhaps they were misled? Would be willing to give it a shot...but what does something like this run? I mean, having the rotating assembly of an MS200T treated might triple the life expectancy, but at what cost? At what point is it "just not worth the trouble and price"?

 

[begleytree]

I've heard that chipper blades can be made harder but it would be a negative benefit. A harder knife is much more likely to break. There is an optimum hardness for a chipper knife and it falls in between being hard enough to hold an edge and soft enough to not break easily.

Agreed.
I'd rather my chipper blades dull up, than chip off. The cost of new blades due to shorter lifespan from removing more material because of chipping out rather than dulling would seem to negate the cost of the process to begin with. Seems like pay for the blades, pay for the process, then replace blades sooner.
But I'm no metal expert by any means.
-Ralph

 

[wedge]

one of my freinds is a custom knifemaker of some noteriety. he uses that cyro quench on some of his blades but latley its been all damascus blades hes been making. ive learned alot about steel from him and his freinds. hell ive even watched em make damascus steel out of titanium (timascus) those guys could make a saw bar that would last forever but it would cost a fortune.

 

[ErrolC]

The wear/life factor would come from an improvement in the toughness/hardness of wearing surfaces, not in reality from a reduction in friction.. the major part of friction in an engine is due to the viscosity/drag of the oil between the moving parts..given that the parts are/should be gliding on an oil film...I'd be a little sceptical about a doubling in fuel efficiency, though the properties of the metals involved would likely change..define fuel efficiency anyway, in this context, given the percentage of energy an engine converts to mechanical effort...but then I haven't tried or witnessed any such results..so what would I know, just my thoughts today...might be different tomorrow

 

[Al Smith]

I've heard some interesting tidbits about cryogenic-ally treating rotating assemblies (read: shortblock) in automobile engines. They reported an increase in lifespan of about 300%. (Toyota 4 and 6 cylinder passenger vehicles and one report of a private individual doing a Hybrid vehicle) Also reported DOUBLE the fuel efficiency. Toyota is rumored to be looking very hard at this type of technology as an OEM process. I understand the longevity increase...but fuel consumption? Someone care to take a stab at that angle? The reports were from a responsible source, but perhaps they were misled? Would be willing to give it a shot...but what does something like this run? I mean, having the rotating assembly of an MS200T treated might triple the life expectancy, but at what cost? At what point is it "just not worth the trouble and price"?

I suppose it has to do with what's called parasitic losses of the engine.As a normal procedure in the manufacture of auto engines,certain parts are induction hardened as a rule.Cam lobes,valve seats etc,normally by means of the Tocco process.As I understand it,certain aircraft engines use,for example 4140 steel cylinders,which can be made quite hard.I can see,perhaps the longevity issue,but I somewhat question the fuel consumption.With the advent of aluminum engine blocks,this ,I would think would cause a bit of a problem,die-casting a liner other than nodular iron.It would seem to me that a hard liner would be too hard to machine out which would mean it had to be honed,which would add a huge amount to production costs.Then again,it's only theory on my part.

 

[klickitatsacket]

What I know about the this is from the gun world and from working as a blacksmith for 2 years. (I had to learn to heat treat all my working edges) I also spent most of my working career as a millwright and fabricator.The process is not just rapidly cooling a hot piece of metal down below zero. The piece is taken up and down and held at certain temperatures for differ-ant amounts of time. It can be quite a complex process depending on the alloy or even the carbon content. The idea is not just to harden the steel but to align the grain structure of the metal. Any Steel with carbon can be hardened. the greater the carbon content the harder it can be made but at the expense of brittleness (I can take a piece of 1095 and make it as brittle as fine china). Alloys try to find the balance between hardness and strength. Aligning the grain structure not only makes the steel stronger but also smooths it out. Think of the ridges on a file. as they move across the surface of the piece they cut. The larger the teeth the more rapid the removal. If the grain structure is linear and matched then there is less wear (less cross grain grinding). Remember growing sugar crystals in school? To get bigger crystals you would cool your solution down slowly. For small crystals you would cool the solution rapidly. In steel small crystal structure is harder but brittle. Large crystal structure is stronger but less ridged. So if you can get the grain structure lined up (and the parts machined on the match of grain direction) and the surface smoother by having a finer structure you will get less friction. Now harder does wear less but that is only a small part of it. When you have 2 surfaces working on each other matching is way more important. If one surface is harder than the other; the softer surface will wear faster than it should. Some of you might have noticed that when running Stihl chain on an Oregon bars that the bars wear extremely quickly compared to let's say a Cannon bar. that is because Stihl chain is a lot harder than the steal in an Oregon bar. The bars and chain from these companies is generally matched in hardness. Many guys like to run Stihl Chain because it keeps an edge longer (this is because it is harder, same reason hand filers tend to hate it) At the same time many fallers do not like to run Stihl bars because they have a tendency to chip out or crack. They wear forever because they are hard but this is also why they crack or bust out when they get pinched. Now if you do not have a problem with pinching your bars then matching Rockwell (hardness) is best. A lot of professionals like hard chain that holds an edge and a soft bar that will take the abuse. Replacing worn out bars is cheaper than constantly fighting dull chain or replacing chipped bars in the field.

Here comes the plug now.:blush: Remember I mentioned allows earlier. GB is making the Titanium HI Tech bars. This is a bar that i built with a titanium alloy. This gives the bar flex like a softer bar and is more resistant to cracking and chipping out, but is hard like a high carbon steal and wears better than even a Cannon bar. I have several companies up in Morton that are now exclusively running the GB Titanium bars. I gave one company 2 to try for out a few months to see what they thought. Three weeks later I sold them 10 bars. They switch everything out from the Oregon brand.

Back to the cryo stuff... I have a question for any one who knows. How does it effect aluminum? I am thinking about pistons and their performance. Has any one ever heard of anything being done like this? Who? In What? and What where the results or the benefits?

 

[Al Smith]

Pistons,ah yes

I can't answer directly to the cryo thing on pistons,but can tell you ,perhaps with too much info how they are made.Shortly in the process after they are cast,they are inserted into a carbonizing furnace.In this portion of the process,carbon is infused into the aluminum alloy.This infusion process gives the aluminum a certain degree of hardness ,more so that just the plain untreated aluminum.The rest of the process is interesting but would be lengthy to descibe,so I'll end it here.

 

[Jackman61]

Cryogenic treatment of steel is useful for transforming retained austenite to martensite. If the initial quench from the austenitizing heat treatment is in-effective through the cross-section of the work piece, there will be austenite that prevails into service. This is lost potential of the material's ultimate performance. Cryo-treating transforms retained austenite to martensite which may be efectively tempered by heat treatment after cryo treatment. If proper heat treatment is applied in the first place, the "band-aid" of cryo is un-necessary. Fully tempered martensitic structure is the goal which achieves the balance of strength and toughness in a material.