Cryo Quench Testing?

E

ELarson

Joined
Dec 3, 1999
Messages
41
I did a search on cryo quenching to see what had been posted on the topic. I found a lot of general information but I'm wondering, has anyone tested knives of similar construction (cryo quenched vs. not) to verify the performance advantage?

As buyer's of knives are we getting a real performance advantage, or is it like a spoiler for your Honda Civic?

From the science side it sure sounds like there is a tangible benefit. Sounds like it might be fun to find out (knife X cut through x inches of rope, while knife Y only cut ....)

Thanks,


------------------
E. Larson
Edmonds, WA


 
I first started Cryo treating almost 10 years ago. My experiece was on manufacturing tooling before I got involved with knives. There is a marked difference in the performance of punches, dies and many cutting tools that are Cryo Treated. One easy way for me to varify this is with our part counters on the many of the machines I make tooling for. It's very easy for me to compare Cryo treated to untreated tooling based only on machine cylces. I make the tooling and do the heat/cryo treatments. Often I replace the tooling in the machines!
I see on a daily basis what holds up longer. Now you you may wonder why we don't cryo all the tooling?? It's because sometimes, even in a multi-million dollar company, we are out of liquid nitrogen and cannot wait for the tooling. That's manufacturing
smile.gif

Neil

------------------
New Hawkbill Pics!
http://www.geocities.com/Eureka/Meeting/5520/index.html

 
Thanks, I read that thread while looking through the archives. I'm in electronic testing and kind of a nut for quantitive testing. I've seen LN2 used for musical instruments (brass), tennis racquets, golf clubs to improve performance. I don't doubt it works, and the personal experience of people like the good Dr. Lathe would be hard to refute. I know with musical instruments you can measure the results with instrumentation and see that the cryo treated instrument produces cleaner tones.

What I'm curious about is the level of improvement. If you can really recrystallize 100% of free carbon atoms into carbides what does this mean to the end user. A 5% increase in edge holding? 10% or more? It would interesting to take two blades and run them through the same heat treat cycle, and then cryogenically quench one. Then test away.

BTW Dr. Lathe, the Hawkbill is a beautiful piece. The curves of the blade and handle flow together nicely. Well done!

Thanks,



------------------
E. Larson
Edmonds, WA


 
I've done exactly that with several steels. My tests were for edge holding and flexibility. I reasoned that if indeed a cryo treated blade cut better, then it might have picked up some brittlness in the process. I cut 1/2" hemp rope, on a scale to measure down force, and called the blade dull when 45 lbs of pressure was required to cut. The flexing test was simply placing the first 3" of the blade in a vise, and flexing to 90 degrees. Here's what I found:

Simple carbon steels
frown.gif
10xx) less than 5% cutting ability gained from cryo treating.

Laminated Damscus (10xx/1018): Same results as simple carbon steel.

Laminated Damascus (1084/15N20): Same results as simple carbon steel.

Chain Damscus (Oregon chainsaw chain): 17% more cutting than untreated blade

5160: 26% more cutting than untreated blade.

52100: 32% more cutting than untreated blade.
These were all single quench/tempered blades. None passed the 90 degree flex test.
Since then I have done similar tests on 5160 and 52100 blades that have been multiple quenched/tempered. And the results were dramatic.
5160 Multi-quech,cryo treated: 35% better cutting than a single quenched, non-cryo treated blade.
52100 Multi-quench, cryo treated: 52% better cutting than a single quenched, non-cryo treated blade.
I did discover that in order for the blades to pass the 90 dgree flex, another tempering cycle at 25 degrees higher than the previous tempering temp was required after the cryo treatment. From my results, I am convinced that the Chromium content was the reason the 5160 and 52100 blades reacted so favorably to the Nitrogen quench. Not enough Chromium to make either of the steels remotely "stainless", but enough to result in the preformace increses.
http://www.mtn-webtech.com/~caffrey


------------------
Ed Caffrey
"The Montana Bladesmith"




[This message has been edited by Ed Caffrey (edited 23 December 1999).]
 
Elarsen,
Many of the commercial "cryo treaters" have lots of performance information. I would imagine that it may be somewhat stacked in their favor, but should still provide some interesting reading.
Thanks for the compliments on the Hawkbill. That model is keeping my BUSY!
Neil

------------------
New Hawkbill Pics!
http://www.geocities.com/Eureka/Meeting/5520/index.html

 
Ed,

Now that's some data you can sink you're teeth into. That the presence of chromium seems to play a role in the effectiveness of the cryo quench is interesting. So the cryo quench alone doesn't guarentee a performance advantage, it's what steel you're treating, and how it fits into the heat treat cycle.

Thanks very much. Your test lays it out so us uninitiated enthusiasts can get a handle on it. Also, the pictures on your website of the "Journeyman Knife of the year 2000" were very informative. I think that's the first I've seen of a step by step on making damascus. It also shows the amount of work involved and why a beautiful pattern welded blade demands such a premium price.

Many Thanks to all,


------------------
E. Larson
Edmonds, WA


 
You must log in or register to reply here.
Back
Top