Diamond Steel XB5 from Russia?

[spudley112]

I was browsing the bay of e today and saw a Bowie Knife advertising a blade hardness of HRC 65. Intrigued, I looked up Diamond Steel XB5 and there was very little info on the steel...just a lot of knives for sale out of Russia. Many of these knives have a pretty high HRC in the 64 and 65 range. I had never heard of this steel before, but was hoping to get some more information on it.

Here is an example of one of the knives I found:

[Gerhard Gerber]

Never heard of this steel before, this might explain it...

XB5 (Russian naming system, written in latin would be HW5) is Russian alloyed tool steel with no direct analogue in the West. Nicknamed almazka (almaz is the Russian for diamond), was used for manufacturing diamond cutting equipment. Excellent hardness, very good edge retention make it preferable choice for hunting knives, but not survival knives – XB5 lacks toughness necessary for chopping. The dotlike pattern visible on the blade is characteristic for almazka. XB5 is not resistant to corrosion.

[spudley112]

GG - Thank you! Exactly the kind of info about which I was curious!

[Gerhard Gerber]

My mentor gave me a sheet of Vanadis 10 SuperClean, it's a Uddeholm product, but as far as I could find out only a few Russians have bothered to use it for knives.

Apparently the stuff is impossible to grind, even in the annealed state

[spudley112]

My mentor gave me a sheet of Vanadis 10 SuperClean, it's a Uddeholm product, but as far as I could find out only a few Russians have bothered to use it for knives.

Apparently the stuff is impossible to grind, even in the annealed state

So basically, once it starts to dull, not sharpener is going to have a very long life if used on it.

[Gerhard Gerber]

Well, if it fights back when you're making the knife, I guess it will be tough to sharpen.
My plan is to heat treat the blades without foil to burn out some carbon (it has plenty) to make it a bit more manageable, and temper them back quite a bit.

[Shuya]

Well, if it fights back when you're making the knife, I guess it will be tough to sharpen.
My plan is to heat treat the blades without foil to burn out some carbon (it has plenty) to make it a bit more manageable, and temper them back quite a bit.

Hmm, why bother with a piece of steel when you can something better?

Burning out carbon is a crappy idea imho, because you have no idea how much carbon you lose, carbon is only lost on a very short distance from the surface, carbon bound in carbides will not be burned and you will burn away iron, too if not done under protected gas (argon) in a induction heater for example.
So not a good idea for household processes.

Those powder steels are made with PM metallurgy for a reason: the alloying elements are not sollutable in the steel at that extend if you want a homogenious matrix. There are limits for soluting elements in steel (for example carbon... only 0.6% are needed for full martensitic matrix, everything else goes into carbides)

And you will coarse the grains, so further heat treatment and/or forging needed.

Good luck with that.

Hang this knife up on a wall and get a decend steel to make your knifes 

[Gerhard Gerber]

Hmm, why bother with a piece of steel when you can something better?

Valid question 
My mentor told me it's not worth it, but it's not a bad steel, just difficult to work.
I'm going to make a cleaver to test it, since the steel is relatively thin so not too much grinding to do, use and angle grinder to remove steel then clean-up on the belt grinder.

I haven't use foil yet and the decard in the kiln is visible, but not catastrophic.  This stuff has 1.4 or 1.6% carbon, plenty, so I'm hoping the decard makes it a bit easier to sharpen and tougher.

Purely an experiment 

[Shuya]

Valid question 
My mentor told me it's not worth it, but it's not a bad steel, just difficult to work.
I'm going to make a cleaver to test it, since the steel is relatively thin so not too much grinding to do, use and angle grinder to remove steel then clean-up on the belt grinder.

I haven't use foil yet and the decard in the kiln is visible, but not catastrophic.  This stuff has 1.4 or 1.6% carbon, plenty, so I'm hoping the decard makes it a bit easier to sharpen and tougher.

Purely an experiment 

Keep us updated.

Even if you use foil you still lose material and the duration to burn carbon is quite a while (and inert atmosphere prevents carbon loss... thats why you apply it...)

Never liked those super steels (or ledeburites in general) for knifes, but thats a pure personal thing.
But knife industry has to come up with something new, and some people in fact enjoy the wear resistance of a CPM S90V... got a knife of that, too, but rarely use it.

[Gerhard Gerber]

Never liked those super steels (or ledeburites in general) for knifes, but thats a pure personal thing.

My mentor now uses Elmax as standard for mono steels, used to be D6 when I met him.
While ago an acquaintance asked me to sharpen one of my mentor's D6 knives purchaced 8 years ago, it had clearly seen considerable use and was still usable.

I love these super steels, but rather on my Spydercos, if a person is able to sharpen a knife I also believe they are better served by a simpler carbon or stainless steel.

The only stainless steel I've used so far is 14C28N, I have no serious issues with decarb, but I got some advice from an Australian maker that uses 12C27, and the easy cleanup after heat treat might be a good enough reason to try the foil.

I paid blood money for the stuff and now I'm to stingy to use it 

Next blades will get cryo treatment as well.

[spudley112]

GG - Darn buddy..I wish I lived closer...always wanted to learn serious bladesmithing. I would love to just hang out in your shop and watch you work and have you school me! The knowledge you guys have is absolutely fascinating to me.

I keep reading and trying to learn...just have not found a local mentor that has specific scientific knowledge (there are a few that turn out those soft pot steel fantasy blades for flea markets) or one that has the time to have me hanging over their shoulder.

[Gerhard Gerber]

GG - Darn buddy..I wish I lived closer...always wanted to learn serious bladesmithing. I would love to just hang out in your shop and watch you work and have you school me! The knowledge you guys have is absolutely fascinating to me.

You live in the land  of milk and honey, you can kick a bladesmith with more experience and knowledge from behind every second bush 

I'm only 5 years and about 70 knives into the game, but I learn by immersion, all my other hobbies have fallen by the wayside.
Never invested as heavily into any hobby,  and the only thing I devoted as much time to was fly fishing.

After all that, I watched a video 2 weeks ago that finally helped me understand Austenite and Martensite and what happens during the heat treat process.
I view this as nerd-level knowledge that's good to have but not absolutely necessary.

What helps is the practical heat treat advice my mentor got literally from the horse's mouth at the Bohler factory, specifically for Elmax.