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.

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

@LonestarTaoboy

Жыл бұрын

You can have my Code 4 when you take it from my Cold Steel Hands

@mmllrjr

4 ай бұрын

to Zfinity and beyond

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?🤣👊

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!

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

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.

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!

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

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

@homeslicesharpening

Жыл бұрын

I do enjoy a low carbide Guinness - I'll have to try Pepsi nitrides too. Maybe crucible will produce S35PN Pepsi with both Carbon and trace Nitrogen. With Niobium ice cubes.

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.

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

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.

@KnifeSteelNerds

Жыл бұрын

Me too!

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

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

@mikafoxx2717

3 ай бұрын

Magnacut, though. K290 is great. Cpm CruWear is also pretty good. We're spoiled with steel these days. Even a great heat treatment on plain steel makes a better than average knife.. and now we can get Excalibur level stuff.

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

@W5rr2nG

Жыл бұрын

Shawn but yea. He’s a great guy and is actually doing things to help the community and expand our knowledge on steels.

@lindboknifeandtool

Жыл бұрын

@@W5rr2nG thanks for the correction, I was looking like a block head.

@mikafoxx2717

3 ай бұрын

​@@W5rr2nGI like that he goes into the edge geometry performance, plus he does great work with fancy metals and heat treating. Geometry, heat treat, and steel all in combination for the best edge. Most overlook at least one of those 3 if not all of them.

Thanks for sharing 👍

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

Shawn is cool and Shawn will get you right

Pumped to hear this

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.

@maseratidyce3587

22 күн бұрын

Dr. Thomas. He’s a doctor. Respect his pronouns! Doc/turr

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?

@KnifeSteelNerds

Жыл бұрын

Vancron is quite expensive, part of that coming from the extra processing step necessary for adding the nitrogen. I doubt the small savings from the lower required temperature would be enough to offset the cost.

Dear god I am down the rabbit hole...

Gonna need some of that NitroPepsi please

Hi there triple b!!!!

THANKS GUYS

Is Pete’s heat treat any good ?

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

@certamen832

8 ай бұрын

I’m afraid not that many people are or ever will be autistically invested in this kinda stuff like we are

@maseratidyce3587

22 күн бұрын

I don’t think there’s millions of people that are interested in metallurgy thru the lens of knifemaking and knife purchasing

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

@KnifeSteelNerds

Жыл бұрын

What hardness are they heat treating to? Production or custom knives?

@dimmacommunication

Жыл бұрын

@@KnifeSteelNerds Production :) " Sanelli Ambrogio " Montana ( wich is owned by Sanelli Ambrogio ) " maglionero " My Sanelli Ambrogio is 57 , my Maglionero is 59 hrc. I like them :) for day to day use it's good 😁 these knives are sold for cheap too.

Very good 👏

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.

@KnifeSteelNerds

Жыл бұрын

I don't think I have any ASP 2053. I will have to look.

@MobileAura

Жыл бұрын

@@KnifeSteelNerds let’s be honest here though, overall, there’s nothing “wrong” with nitrogen steels such as Vanax and LC200N (budget Vanax), Magnacut being behind Vanax and above lc200n, which absolutely dominate every single knife steel in the industry without a close competitor. Nitrogen steels are the future until new steels can prove otherwise.

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.

@KnifeSteelNerds

Жыл бұрын

Boron is used in steel but it doesn’t increase hardness/strength. It is a hardenability element meaning you can quench the steel more slowly and still form martensite. Boron isn’t typically used in high carbon steel because the hardenability contribution isn’t as effective in them. There is some research in steels with borides instead of carbides for wear resistance but the hardness still comes from carbon.

@hunter-tm2kl

Жыл бұрын

@@KnifeSteelNerds that's interesting. thanks for the info.

@thorwaldjohanson2526

3 ай бұрын

Have seen it mostly used in padlocks, where the bar is made of boron alloy steel. It's seemingly very abrasion resistance but I have no Idea really.

@mikafoxx2717

3 ай бұрын

​@@thorwaldjohanson2526Yeah, I've wondered about that stuff. I don't know about abrasion resistant but it's meant to be hard to cut. Toughness would have to be high, no?

@willabernethy4832

21 күн бұрын

Morakniv makes their axe with boron steel. It gets high praise from the only guy that I know who uses one.

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!

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 😆

@dimmacommunication

Жыл бұрын

The Viper wasn't made in 14c28n , maybe 12c27 . I like nitro-b :) cheap and effective alternative to x50

@Cid_1

Жыл бұрын

@@dimmacommunication I know, it was just an example of having 2 different steel on the same knife in a blind test. Yeah so far Nitro-B seems like a very nice steel for kitchen style knifes at reasonable prices :)

@dimmacommunication

Жыл бұрын

@@Cid_1 For sure, small problem is that I think most producers just don't heat treat it properly.

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.

@KnifeSteelNerds

3 ай бұрын

Yes as you've noticed the definition of steel being "iron plus carbon" doesn't always work. But I haven't seen anyone try to give a newer or better definition. The retained austenite can stabilize when carbon diffuses to the interface between martensite and austenite. With high temperature tempering it can be possible to convert all or nearly all of it. You can cryo treat bainitic steels.

"Mo' Nitrogen, Mo' betta!" Lol

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?

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

@KnifeSteelNerds

Жыл бұрын

Should be fixed now

@danrussell9357

Жыл бұрын

@@KnifeSteelNerds 😃

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

@KnifeSteelNerds

Жыл бұрын

There are one or two very small studies on it but I’ve never managed to get any. Unless it has become more available than a few years ago.

@_BLANK_BLANK

Жыл бұрын

@@KnifeSteelNerds as far as I know it's not, but I have no way to handle it, so I've never searched, but it seems like it could be the gold standard for cryo (I would think), if someone did find it.

@dimmacommunication

Жыл бұрын

Liquid helium Would cost an arm and a leg

@_BLANK_BLANK

Жыл бұрын

@@dimmacommunication no doubt it definitely would.

@GemAppleTom

Жыл бұрын

@@KnifeSteelNerds So far I’ve found one conference paper that investigated LN and LH cryogenic treatment and the conclusion was that LH doesn’t give any benefit above LN. I haven’t gone into it in great detail so I can’t rule out errors in the experimental procedures. Zurecki, Z. (2005). Cryogenic quenching of steel revisited. Air Products and Chemicals Inc. Heat Treating: Proceedings of the 23rd Heat Treating Society Conference I’ve got university access to a lot of papers so if there were any you were interested in I could look them up (without violating copyright, I must hasten to add). (Though on a personal note it does mention that carbide clustering at cryogenic temperature has apparently be shown experimentally - something my Dad proposed in the mid 90s)

What about boron?

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?

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

@KnifeSteelNerds

11 ай бұрын

Nitro-B is a very low nitrogen steel so it behaves similarly to nitrogen-free steels but with a little extra hardness

I loved this

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

@KnifeSteelNerds

Жыл бұрын

I will have to do some reading on that one. And figure out why solid austenite can dissolve more nitrogen than liquid steel.

@mikafoxx2717

3 ай бұрын

​@KnifeSteelNerds Reverse solubility? Sort of like carbon dioxide in water.

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

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

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

@MountainFisher

Жыл бұрын

Ever watch the video on Cedric And Ada where Peter tries to fix a chip in it? kzread.info/dash/bejne/c6l8s7tsYJOnkcY.html

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?

Smaller softer nitrogen pp Bigger harder Carbon pp

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

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

@monkpato

4 ай бұрын

What's your point? Just because one steel out of hundreds is tempered lower doesn't mean that 300 isn't low.

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?

@KnifeSteelNerds

Жыл бұрын

Well using carbon leads to higher hardness so however you want to visualize it the carbon is better at reaching high hardness levels.

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?

@KnifeSteelNerds

Жыл бұрын

Plastic deformation is controlled by the yield strength which generally correlates with hardness though there are cases when you can have a low yield strength relative with to the hardness.

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

@KnifeSteelNerds

Жыл бұрын

TWI-Global is a welding organization. They’re talking about welding of low carbon, low alloy steels. The article you reference says they want double the Al of N so that it forms AlN leaving no free nitrogen in the steel. Which is the opposite of what we want from the nitrogen in the steels discussed here.