Increasing sharpness of the blade by 2 points.

[nozh2002]

Liquid nitrogen treatment increase hardness of the blade in 2 point. However it can not be done in the household.

What I found out is that similar effect you may achive in the regular freezer. I did left 420 knife in the freezer by accident and have it here for about few monther until accidentely find it there laying on the door pocket. Just being curiouse I try it on my sharpening test and it shows sharpening increase in two points on thread test - it was 90gramm before and 70 grann after.

Initially I thought that this is deblurring effect noticed alredy by some Russian knifenuts living far North. I resharpen it and find out noticible increase in sharpness even using same procedure I usually use against same blade I tested before freezing. It shows stable 50 grams sharpness which easy outperform Spyperco Military BG42 - solid 60 grams.

This make me to continue my experiments with different steel. And for all of them I noticed increase in performance - increase in sharpness.

However it require blade to be in freezer for few weeks to achive noticible improvement. But few days ago I had an idea that problem is that I keep knife inside freezer but surrounded by air - it has very low thermo-conduction (I hope this is right term). I decide to try to keep it in different enviroment.

Water will just turn ice - I need some kind of snow like substance. I though about vodka - but who will waste vodka for this. What can it bee? And Yes - Ice Cream! This is ideal for freezing blade treatment. I run into nearby Bascin Robins and got different ice-cream for experiments. It was:

1. IceCream
2. Frozen Yogurt
3. Shake
4. Icee

So I found out that in result time of treatment significantely increased in any case - it is matter not weeks but hours! Like in 4 hours I have 2 point sharpness increase - same as keeping blade in freezer on the air for two weeks. However it looks like for some reason high vanadium CPM steel preffers Frozen Yogurt - I have 4 points increase, while regilar steel had only 2 point (CPM S30V and CPM S90V vs ATS34). I am not sure why this happen - just noticed this effect.

I think this all very promicying. I can not explain it from metallurgy point of view - my education is applied math. I heart about austenit turning martencite during deep freezing. I know that ZDP is treated by dry ice. But it seems it works with more available and cheaper substances.

I think we have new horizon opened and I may expect some household treatment which may turn generic steel like 420HC to perform like ZDP may be by some mix or combination.

And most important anybody can try it by themself right now!

Please report you results in this thread.

I will summarize resulti in tables and charts and will post co mplete presentation later - may be tommorow.

Thanks, Vassili.

P.S. I isolate steel before putting it into substance to prevent corrosion.

 

[Esav Benyamin]

Will this work as well after April Fools Day?

 

[samhain73]

LOL thats what I was thinking...........

 

[WadeF]

Hopefully, then I have an excuse to try every flavor of ice cream possible.

 

[symphonyincminor]

I've been conducting my own experiments involving Surgical-Grade Stainless Steels and deep-cryogenic freezing cycles in ice cream. I find that chocolate and cookies & cream types of ice cream yield better results than vanilla (does chocolate have a different freezing temperature than vanilla?). These results are preliminary and non-scientific in nature. Although I do not have Rockwell hardness testing equipment, it seems that I can get Surgical-Grade Stainless Steel up to 65-68 hrc, on par with my ZDP blades. No chipping, although sustained toughness has been a factor (some of the blades were brittle).

I'll post more results later and pictures later!

 

[Esav Benyamin]

Was some of the peanut brittle and did you notice any chocolate chips?

 

[Emanuel]

All this talk of metallurgy is making me hungry.

 

[ashtxsniper]

So is this for real? Just stab into ice cream and stick in the freezer? Sounds to good to be true.

 

[Peter_E_Ryt]

I feel stupid... VERY stupid. I didn't do it, but I thought it was legit... I deserve to be slapped.

 

[Cliff Stamp]

This processess (freezer treatment) was advocated by a number of well known knifemakers before liquid nitrogen was well known. I have also heard other things such as potato quenching, magnetic flux tempering (N-S) alignment, and even blood quenching, all from well known makers.

-Cliff

 

[Esav Benyamin]

Water will just turn ice - I need some kind of snow like substance. I though about vodka - but who will waste vodka for this.

Who will waste Baskin Robbins for this ??? Wouldn't Dolly Madison work as well?

Of course, Ben & Jerry's would probably soften the steel ...