Questions Regarding home cryo

[WalterDavis]

So, I understand the basics behind cryo treatments, and I understand some steels respond to it more than others. I'm working with 1075, 1095, O1, and 5160. My questions are:

1. Will I see results with the O1 and 5160 doing a home cryo treatment (dry ice and acetone)?

2. Will doing a home cryo treatment help my knives (in all 4 steels) keep from becoming brittle in extreme cold (I've heard that outside temperatures can make a knife brittle, and I've got some friends in AK that want some knives)

3. When doing a home cryo, does all the acetone evaporate? I know, it sounds like I'm being cheap, but the local hardware store wants 16-18 bucks a gallon, and I usually only heat treat 4 or so knives at a time, so I don't want to throw money away.

Any other tip, hints or tricks to make home cryo work? What is your setup like, what order do you do your cryo treatment in?

Thanks,

Walter

 

[Rob!]

This is just opinion - based somewhat on experience - somewha on reading and somewhat on listening.

If I used only those steels, I would not bother with cryo. Since I keep cryon around for stainless and high alloy steels, I use it on those too.

Re: Q1 - I don't believe you'll see any negative results. Whether you see positive results will depend on the rest of your heat treat process (Is there lots of RA?) and the use the knives are put to. (There won't be much difference in a show case.)

Re: Q2 - Interesting question. I find it hard to believe that even Alaska gets cold enough to make heat treated and tempered steel brittle. I guess I'm saying I wouldn't challenge the truth of that - but I wouldn't suggest it to a customer either.

Re: Q3 - most of the acetone will remain, eespecially if you keep iin the can/jug between uses. The Dry ice will only last about 24 hours.

We use liquid nitro because it lasts much longer (4 - 6 weeks) and travel is more expensive than the product for us. We Austenize, Cryo, Temper and Temper. With 1095, I would absolutely temper before any cyro - and then double temper again.

Hope this helps

Rob!