154cm and cryo

DLBrothers

Well-Known Member
Knowing that there are numerous options to cryo SS, I was wondering what folks are commonly doing and what if any testing has been done to evaluate the results (either formal or observational). My particular question is with 154cm and cryo txt. I am new to using this SS and have read several options and want to know what you fellows have found most beneficial.

A. Cryo immediately after initial quench for however long- assume at least 4 hours, basically cryo being part of the initial quench.

B. Cryo after a snap temper, then do full temper regimen.

C. Cryo after one cycle of normal temper

D. I don't do cryo with 154 cm due to minimal benefit.

Thanks dogs!
 
I agree, A is what I like, B is safe option. I have seen a point to 1.5 gain in RC just from dry ice/acetone, in CM 154 austentized at 1950 and plate quenched.
 
I just cryo'd some cpm154 over wknd, and went right from HT to cryo followed by a temper, cryo, and another temper. Some of the older high carbide tool steel like D7 I snap temper because it is may crack easier, but not CPM154.
 
I heat treat, quench until room temp and then in the LN Cryo. From my understanding of it this process gives you the most benefit of the cryo treatment though you do have the ability to generate cracks so its a risk. my thinking was if i break a blade in this process then maybe there was a fault from the start

I do this with 440C, CPM154 and S30V but when i have been doing carbon steel like 1095 i heat treat and then snap temper then cryo.

steve
 
I've always been told that any type of cryo or sub zero treatment to simple steels (10xx) does nothing.

Crucible told me when I asked, that I should "snap temper", then cryo. Maybe they've changed their minds.
 
I had been told by some people that it helps quite a bit with edge retention in simple steels but more have told me that it does nothing. So far none have told me that it hurts anything though so I figure why not, my cryo tank is just sittin there anyway :)
 
I've always been told that any type of cryo or sub zero treatment to simple steels (10xx) does nothing.

Crucible told me when I asked, that I should "snap temper", then cryo. Maybe they've changed their minds.


Please excuse my ignorance, would someone please tell me the difference between a "snap temper" and otherwise a regular tempering cycle. Thanks, Rex
 
I may be wrong but my understanding of a "snap temper" would be a short temper cycle (1hr) at a temperature about 25deg below the temperature you intend to temper with, example if you were going to temper for 2hrs at 400deg you would snap temper for 1 hr at 375

but i could be completely wrong also :)
 
I think you have the right idea Lerch, but the precision doesn't matter. A snap temper is intended to take a little stress off while not affecting the real outcome. Let me choose an example other than cryo. If I have a blade out of quench, that I don't have a kiln ready for temper, I may do a 'snap temper' in the kitchen oven. Now I know how inaccurate the kitchen oven can be - and I want to eventually temper the blade at - I dunno - say 400F. I may snap temper at 300F. Is that going to do anything for temper? Not likely! But it will take a bit of the stress off till I have a kiln ready for the proper temper - and it won't overtemper even if the oven is off.

Same applies if you feel you need a snap temper before cryo. Just take the edge off the stress a bit.

FWIW, I cryo all air quench steels, because I believe it will do no harm - and usually is of significant benefit.

I don't cryo simple carbon steels because it is of questionable benefit - and more importantly, I believe has significant potential for damage. My understanding with these steels is that they should go directly from quench to temper.

... but hey, I'm open to change if someone wants to risk some blades. :)

Rob!

Rob!
 
Now I understand, since I have taken my blades straight from quench to temper, I guess I never needed to know that. And I use mainly 10XX and W steels, I still need to choose a stainless...when ever I feel I have my 2 chosen HC steels mastered (enough) I'll worry about that then. Thanks Guys,Rex
 
Ya it was expressed to me that the simple steels should go straight from the quench to a temper cycle

it is after this initial quench i do a cryo treatment, again i am not sure if it helps anything but i figure if it breaks then it was meant to be and if not then maybe just maybe it may hold a better edge, then i quench 2x
 
Thanks fellow KD's! I was already leaning that way - I have done 440C and ATS-34 by LN cryo straight off the quench plates with good results. But it never hurts to test the waters and learn from others experience with a new steel. I do let my previously mentioned blades cool to room temp after the plate quench before I put them in the LN - and do so SLOWLY. I usually let them set there overnight for convienence sake. Pull them out by the attached wire and hang them by the same to warm back to room temp- then temper cycle as needed.
 
Back
Top