New Research on Nitrogen Knife Steels - It Doesn't Look Good 

Something that I want to mention - we tend to think only in terms of knife and knife performance, but retained austenite is a pretty big issue for industrial parts as well. ESPECIALLY when we only really think in terms of HRC and not microstructure. I was working for a company that re-heat treated pump components after applying our coating to them in a vacuum furnace. Some of those pumps were made out of CA6NM, a 400-series esque cast alloy and I was having issues where the parts we were heat treating tested OK (ie we hardness tested it and gave it the thumbs up) but the customer was complaining about how hard they were to machine. Long story short, I figured out that the issue was that we were not allowing the parts to get down to room temperature between the quench and temper cycles (and keep in mind this is being done in a forced-air gas quench). I had retained austenite that was finally turning into untempered martensite after the temper cycle and since we were hardness testing right after HT, we never picked it up. If it wasnt for me knowing about retained austenite from making kitchen cutlery as a hobby (after reading about cryo-treatment on the KSN site), I would have spent a lot more time arguing with the customer before sifting through 100+ heat treatment records and matching up the problem parts with a bad HT. Thanks for these videos. They are so amazingly helpful.

Mr. Thomas; thanks so much for all you do in the metallurgy industry, and especially for all of the information you provide to random guys like me, so we can gain a basic, surface understanding of why different steels behave the way they do. You’re very much appreciated!

Cronidor 30- Henkles made a premium line of kitchen knives with it a decade ago. Do I get my "Old School" card?🤣👊

You can have my LC200N when you take it from my cold dead hands 😂

I really admire and appreciate your work sir I nearly invariably use your heat treat recipes for all of my knives and different knife steels. Thank you for so much useful information

I'm a lousy knife sharpener, but today I accidentally poked my finger and it bled. Getting better! I'm aiming for lousier than your average knife sharper now. 😜 Thanks for this video!

Nice to hear from you again!!!

Great video man. Thanks for the info, I had no idea retained austenite could make steel harder to sharpen. For finer edge on low grit I like to remove the burr edge leading than thin it down edge trailing.

I really enjoyed this one!!! And hoping for more, very interesting talk!!!

Consider making a basic chemistry-physics lecture video with pics to help visualize the concepts of the diffrent phases of matter within solid steel. The idea of Cr in solution vs in a carbide, martensite, austenite (retained vs transformed) and how it all applies to knife steel and or heat treatments. Im sure it will receive millions of views.

Excellent. Just before midday on a Saturday Knife Nerd Upload. Most excellent….

Still not quite as sold on the nitrogen steels as I was experimenting with the niobium ones, but I've certainly gotten a lot more respect for the Nitro-B which I think I'm going to have to try out and see how well it goes for some applications.

Almost a decade of 14C28N use with both fixed and folding knives, and it has proven to be an exceptional steel. From Scandi bushcraft to full-flat ground delicate slicers, it excels in every category! Not to mention the fact that it's actually affordable!

Nitrogen refines the microstructure of Pepsi but lowers the carbide content 😤

"Everything is smaller with nitrogen " "You want that smooth, creamy head" - BBB

Thank you Mr. Thomas for your research you do on metals. I find it very interesting to learn about. For a man to be able to learn some of the key details you teach based on your research is a privilege I don’t take for granted. Thank you sir for teaching us.

Thanks for sharing 👍

Pumped to hear this

I try to stay as informed as I can about metallurgy and all things in knife work in general but even after all I feel I’ve learned as an end user k390 just still seems to be the only high end steel that seems to do it all it’s absolutely amazing… far beyond what looking at charts would have you expect

THANKS GUYS

You should try a catra test with 1.4116 and nitro-b Problem is that most makers use Nitro-b without any cryo etc...

Gonna need some of that NitroPepsi please

I really like these larrin + Shawn discussions. Edit: dingus spelling.

Shawn is cool and Shawn will get you right

This is great. You should have millions of subscribers. Thank you.

Very good 👏

Here in Italy a lot of makers use Nitro-B , so this video comes in handy 😉😁. I also have knives in Nitro-B, not that much difference to 1.4116

Hi there triple b!!!!

Where's Nitro-V from New Jersey Steel Baron?

IF YOU CUT THE NITROGEN IN HALF ON LC200N COULD IT GET TO A HIGHER HARDNESS AND WOULD IT CHANGE CORROSION RESISTANCE OR MICROSTRUCTURE AND TOUGHNESS? I WISH YOU. COULD TEST A SAMPLE LIKE THAT!

Does Vancron potentially have processing cost benefits over 10v, or does the nitrogen-adding process cost enough that it overcomes the cost reduction from lower temperature heat treating?

Dear god I am down the rabbit hole...

The only experience I got with Nitro-B/1.4116N is with 1 kitchen knife (Viper Sakura Chef @58-59HRC). It's a pretty nice knife so far, but it hasn't blown me away or anything. Though a Chef knife like that is probably not the ultimate way to test a steel 😅 And if there were 2 versions of the exact same knife 1 with Nitro-B and the other in 12C27 N680 or 14C28N, in a blind test over a period of time would most people notice a massive difference? Probably not, but the only thing I can say is that it (so far) seems to be a pretty decent steel for kitchen knives with my 1 experience 😆

Is Pete’s heat treat any good ?

Just a few questions/thoughts. Could a hypothetical steel use zero carbon and only nitrogen for hardening? Would it still be considered steel by definition? Another, is about retained austenite. What prevents the last few % from transforming no matter what you do with cryo and several tempering cycles? Can you cryo treat bainite tempered steel? Either way, interesting chat. Love the site and videos. Especially for forge heat treating without completely screwing it up.

I wonder what a bit of gold could do. It may change how vanadium carbides grow. Or not. Has anyone even tried to dissolve metals in nitric acid, precipitate these nano powders and just squish them in a press?

Having trouble holding back your resentment for N2. Pretty funny. Although careful, your opinion sways the public. Vanax is excellent in saltwater. At any rate, thinking about the whole N vs C interstitial elements debate, how about other tetravalent elements, you mentioned P and Si, but they don´t end up interstitial(?) I was thinking Platinum...Its wild to think about it, granted Im not a chemist so I dont know if it is soluble in liquid iron or if it ends up interstial... what do you think?

I've seen German knives using Nitro-B, I think Giant Mouse just used it in their new kitchen/chef's knives @60hrc

Hi Larrin, thanks for all the extensive information. I heard you are looking into a mysterious steel called ASP-2053 later this year? I’d love to see your take on it, I’ve heard it’s like K390 but on steroids, I have some coming soon and can’t wait to work on it.

Would it be possible to replace carbon with boron? I know that it's not too difficult for boron to form borides with transition metals, although I have no idea how that translates to the knife making and heat treating process. From some googling, it does seem that boron steels are used in the automotive industry and I have some padlocks with boron steels, but I couldn't find anyone trying to use it in tool/knife steels. Wonder why that is.

"Mo' Nitrogen, Mo' betta!" Lol

What about boron?

If the link to the article doesn't work, then you can just click the home button on the website to get it.

One thought I've had is, what would happen, if someone tried using liquid helium for cryo. I'm not saying its practical, and I'm sure it's not cheap or easy to get. But I would be interested to see what results could be had with these steels when using it

I loved this

lets wait for the secondary effects in brain from nitro X beverage...

The amount of nitrogen that can dissolve into steel is dictated by Henry's law.

Me, Dragon Knives. I’ve sent it to Japan & China and it’s headed to Portugal😊🔪

Smaller softer nitrogen pp Bigger harder Carbon pp

why don't they make more blades in Tungsten Carbide like the Sandrin stuff??

Nitrogen gotta be good, it is 80% of the air in the atmosphere. Gotta have that carbonic acid in your soft drinks.

Have you, by chance, looked into the newish emerging world of "High Entropy Alloys"? I recently saw Breaking Tap's video (watch?v=Vq_6mAAbfFY) on the subject and it seems like this could be very interesting with future knife steels potentially. Any thoughts?

LOL... a 300F temper is NOT low. They temper fucking ZDP189 in boiling water (literally).

CORRECTION: NITROGEN IS A BIGGER “BULLET” THAN CARBON (MIGHT EXPLAIN WHY IT DIFFUSES EASIER INTO THE IRON MATRIX). THE QUESTION REMAINS A PHYSICAL ONE: WILL THE CARBON BE PHYSICALLY MORE EFFECTIVE AS A “STICK IN THE WHEELS” (IF NOT LOCKED INTO A CARBIDE)? IE: BE THE RIGHT “KEY” THAT LOCKS IN THE STEEL MATRIX?

p̴r̴o̴m̴o̴s̴m̴

NITROGEN IS SMALLER THAN CARBON… Wonder if there is both a Physical as Well a Chemical difference. Carbon atoms act as “Sticks in the wheels” of the matrix, Smaller atoms might be less effective, eg: Might the steel be more prone to plastic deformation at the same hardness too?

Didn’t see any aluminum in any of the steels listed. “WHY NITROGEN CONTENT MUST BE HALF THAT OF ALUMINIUM IN STEEL” twi-global.