Sub zero cycle in home shop???

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knifemaniac

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Jan 19, 2007
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Hello, all. :) I have option to get some liquid nitrogen and I am wondering can I make this sub zero quench in my shop without any digital controlers for temperature....? I read about sub zero quench in -70C (-94F) and second way in -300F....?

I read that only soak the quenched blade in the nitrogen will make a crack. And what are the following steps?

1. Quench, temper, Sub zero
2. Quench, Sub sero, temper.

I want to make knives in 440C, ATS34, 154CM, and other stainless.

Some makers make few Sub zero cycles.
Sorry if I begining old thread again. :D
 
knifemaniac said:
Hello, all. :) I have option to get some liquid nitrogen and I am wondering can I make this sub zero quench in my shop without any digital controlers for temperature....? I read about sub zero quench in -70C (-94F) and second way in -300F....?

I read that only soak the quenched blade in the nitrogen will make a crack. And what are the following steps?

1. Quench, temper, Sub zero
2. Quench, Sub sero, temper.

I want to make knives in 440C, ATS34, 154CM, and other stainless.

Some makers make few Sub zero cycles.
Sorry if I begining old thread again. :D
Click to expand...

2. Quench, Sub sero, temper.

I feel that those stainless steels should go directly into sub zero without a snap temper as a continuation of the quench. Some people say you should snap temper tool steels. My last batch of D2 was done with a snap temper of 350 for about twenty minutes. Some people go higher or longer. I think I prefer the steel without the snap temper and I will go back to going directly into dry ice without it. Now, a snap temper before a LN quench is a different story and is something I'm trying to work out right now. If I were going directly into the liquid I would probably snap temper tool steel. I wouldn't with stainless unless I started getting problems such as cracking or brittleness.
 
I go straight into Liquid Nitro from quench. (room temperature). I have had no problems with cracking. When I plate quench these steels, they go from 1950 to under 100F in less than 90 seconds. Thats about 1233 degrees per minute. Liquid nitrogen takes about 30 seconds to get blades down about another 400 degrees - or 800 degrees per minute. WAY less violent.

Maximum conversion gain ocurrs when you go stright into cryo. In the absence of a good reason not, I choose maximum conversion.

As for Liquid nitrogen in the home shop, I guess the first question is about kids. It would have to be secure from accidents involving children or drunken friends.

Having said that, the stuff is fairly easy to deal with - gassing off is not hazardous. It keeps well in a dewar. Be sure you can transport it safely.

Liquid nitrogen will keep in a dewar for a month or two depending on use, volume and container. Dry ice will be gone in a couple days no matter what you do. I prefer the Liquid Nitrogen.

Hope that helps.

Rob!
 
well...I've been using dry ice for about 5 years..I can buy 10lb blocks at the grocery store:)

The other option is to make your own. There's a few places on the net thats sells the stuff. Google
 
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