CPM-3V versus INFI

I've always wondered if INFI is a proprietary steel, or proprietary heat-treat of a common steel.
I find it hard to believe that a steel manufacturer makes up a special steel for Busse only.
 
That's something we'll probably never know for sure. Whatever it is, it's a damn good cutlery alloy and from a marketing perspective, Jerry Busse has certainly made the most of it.
 
Brules1 said:
I find it hard to believe that a steel manufacturer makes up a special steel for Busse only.
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I don't wanna debate INFI "proprietarity", but steel mill making special alloy for maker isn't something unbelievable, for Busse or anyone else...
 
Or if it does, it will likely only get better.
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I agree. They obviously have worked hard to make their name kind of synonymous with quality and don't see them throwing it away any time soon.

And Gator, If you are buying entire heats of steel from a foundry you certainly have a steel modified to your specs.

Whenever I've gotten steel I've always recieved a analysis of that particular batch of steel. Different batches vary.Heck, the specs are more like a median. Carbon may be from .80 to 1.40% and still be within spec on some steels. Every batch will change, and every heat treat has to be tweaked accordingly.

One batch of steel I recieved a few months back had extras like copper and a few things that aren't in the book specs for that steel. Impurities? Tweaks? I'm not sure but the foundry was forthright about it in the analysis so I could tweak the heat treat if needed. The quality makers will usually make test knives from new batches. All part of quality control and part of the things that make the Randalls, Busse's, Doziers, Ferhmans etc. so consistently good from batch to batch, year to year.

Not to put anything or anybody down but a total of 40 or more hours spent in heating and cooling and cryo cycles isn't at all uncommon with some of the alloy tool steels. Especially air cooled ( A series), for instance that has cooling times down to room temp. that alone may take almost day for a batch in a decent sized oven, just waiting to begin the next step.

Research how long it took the US to make a 16 inch naval rifle barrell for a battleship. The smelting, and heat treating and annealing could last into weeks before the machining even began.
 
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Infi may be a mystery, but SR101 is just 52100 with a Busse Group heat treat. I suppose comparisons of 52100 and SR101 would be a good indicator of the quality of their heat treat.

A Mule team sized SR101 knife (62–64 Rc) is coming down the line from Scrap Yard Knives soon. Might be interesting to compare to the 52100 Spyderco Mule.

There's also a thicker CG version with lower hardness (58-60 Rc) for the abusive types.

Specs here:

http://www.scrapyardknives.com/ubbthreads/showflat.php?Cat=0&Number=454885&page=0&fpart=1&vc=1

Pictures here:

http://www.scrapyardknives.com/ubbthreads/showflat.php?Cat=0&Number=447921&an=0&page=0#Post447921
 
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52100 at those hardnesses is pretty good stuff. Spyderco's mules RC'ed out consist. at 62-62.5 and they were still tough, with excellent edge stability.

I have an O-1 skinner at RC 64-65 now and it's not as brittle as most would think. It's a skinner though, and doesn't need chopping/batoning toughness. I like running these steels warm.

I've had 1095 at 65-66.

Should be good stuff and as usual decent prices from Scrapyard. I like their stuff.
 
The Mastiff said:
I was never comfortable talking about "Carbon V" steel because that steel didn't exist. I feel the same way about "Infi".

IMO Busse makes great knives but overprices them by 30% or more. Makes up a name for a steel from the steel catalog, and has a great business.

I prefer 3V over A8 (mod) for choppers for it's greater wear resistance.

Lets drink.
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I agree with your preference of 3V over A8 (mod) for wear resistance.

An aside: A couple years ago Jerry Hossom said that Crucible told him that they had quit producing A8 mod. They now buy theirs from China.

Who says Chinese steel isn’t any good?:D
 
The Mastiff said:
One batch of steel I recieved a few months back had extras like copper and a few things that aren't in the book specs for that steel. Impurities? Tweaks?
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Impurities. Much of new steel today is recycled, and there are 'leftovers' from the prior products.

I would have had an order in for some steel in this same class we're discussing, but have been having some other pressing issues.
 
Hi, it seems the next evolution in knife steel is to develop a steel with the attributes of CPM-3V merged with corrosion resistance! :thumbup: I am not knowledgeable enough with metal to know what needs to be combined, but whoever does it first will have the market sewn up! :eek:

Cordially,

BabyJWuu :D
 
i would appreciate comments on higher chrominum in alloys like 3v. once you make it high chrominum would'nt 3v be something other than 3v. i also wondered if real high chrominum doe'st tend to make alloys more prone to brittleness.
dennis
 
DennisStrickland said:
i would appreciate comments on higher chrominum in alloys like 3v. once you make it high chrominum would'nt 3v be something other than 3v. i also wondered if real high chrominum doe'st tend to make alloys more prone to brittleness.
dennis
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Yes it does, this is why you don't use stainless in swords.

A stain resistant 3V would likely be the "perfect" steel for a lot of people. Though I think many of us could handle even just minimal stain resistance. Despite using my Dozier Hunter knife on food regularly, I've never had the D2 so much as build up a patina on me.
 
i would appreciate comments on higher chrominum in alloys like 3v. once you make it high chrominum would'nt 3v be something other than 3v. i also wondered if real high chrominum doe'st tend to make alloys more prone to brittleness.
dennis
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Dennis, just about any carbide former will cut down on toughness and edge stability once the carbide fraction gets high enough. 3V has the large, hard vanadium carbides in it for excellent wear resistance but it's overall carbide fraction is low enough to still allow it to be tough, with good edge stability.

3V's carbide fraction is only 5% ( Note: corrected to 8.5% in edit)
S30V's is 14.5% ( very good for such a wear resistant stainless steel, BTW)
S90V is a whopping 23%

10V, though even more wear resistant than S90V has only a 17.5% carbide fraction, so that tells you that carbide fraction isn't the only factor. It's all vanadium carbides, whereas S90V includes chrome carbides. 10V also gets harder, so you get better edge stability, slightly better wear, but no corrosion resistance unlike S90V. Neither are considered tough like the low carbide, simpler steels.

This is just the tip of the iceberg though I'm touching on.

BTW, CPM M4 has 12.5% total carbide fraction which explains it's toughness for a very wear resistant steel. Run hard it's pretty close to the S90V class in wear resistance, with better edge stability. Pretty amazing actually.

Some others:

S125V = 28%
S110V= 22%
440C = 12% ( all chrome carbides)
154cm = 17.5% ( higher than S30V, which has more wear resistance. That's because 154cm is mostly moly + chrome carbides rather than the Vanadium plus chrome in S30V)

• HARDENED STEEL • 60/65 HRC
• CHROMIUM CARBIDES • 66/68 HRC
• MOLYBDENUM CARBIDES • 72/77 HRC
• TUNGSTEN CARBIDES • 72/77 HRC
• VANADIUM CARBIDES • 82/84 HRC

taken from:http://www.crucibleservice.com/eselector/general/generalpart1.html
 
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The Mastiff said:
Dennis, just about any carbide former will cut down on toughness and edge stability once the carbide fraction gets high enough. 3V has the large, hard vanadium carbides in it for excellent wear resistance but it's overall carbide fraction is low enough to still allow it to be tough, with good edge stability.

3V's carbide fraction is only 5%
S30V's is 14.5% ( very good for such a wear resistant stainless steel, BTW)
S90V is a whopping 23%

10V, though even more wear resistant than S90V has only a 17.5% carbide fraction, so that tells you that carbide fraction isn't the only factor. It's all vanadium carbides, whereas S90V includes chrome carbides. 10V also gets harder, so you get better edge stability, slightly better wear, but no corrosion resistance unlike S90V. Neither are considered tough like the low carbide, simpler steels.

This is just the tip of the iceberg though I'm touching on.

BTW, CPM M4 has 12.5% total carbide fraction which explains it's toughness for a very wear resistant steel. Run hard it's pretty close to the S90V class in wear resistance, with better edge stability. Pretty amazing actually.

Some others:

S125V = 28%
S110V= 22%
440C = 12% ( all chrome carbides)
154cm = 17.5% ( higher than S30V, which has more wear resistance. That's because 154cm is mostly moly + chrome carbides rather than the Vanadium plus chrome in S30V)

• HARDENED STEEL • 60/65 HRC
• CHROMIUM CARBIDES • 66/68 HRC
• MOLYBDENUM CARBIDES • 72/77 HRC
• TUNGSTEN CARBIDES • 72/77 HRC
• VANADIUM CARBIDES • 82/84 HRC

taken from:http://www.crucibleservice.com/eselector/general/generalpart1.html
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Ah, but what about free chromium? Typical stainless steels in cheaper knives don't really have any level of wear resistance worth noting, but they are still pretty brittle for the most part.

M4 is really about as close to perfection as I've ever seen in a folding knife, with corrosion resistance being the only real downside(I don't really need 3V/A2 class toughness in a folder). I'm thinking that a nitrogen alloy steel might be the answer. It's said that vanadium carbides form easier than other carbides, and so I would think it's safe to assume that the same can be said for vanadium nitrides. With the currently developing powder metal technology these days, it might be possible to make a wear resistant steel with a high volume of vanadium nitrides for wear resistance, while only having a bare minimum volume of chromium for corrosion resistance.

I've personally never had corrosion issues with my mirror polished D2(granted the heat treat will make a difference in free chromium), and more stain resistance than S30V would be overkill IMO. The idea being that only vanadium(or other nitride former other than chromium) makes up the nitrides while most if not all of the chromium is free.
 
many thanks to mastiff & noctis for carbide info & how it affects ductility. if i'm correct ductility relates to the index numbers of the charpy measurements.m4 seems to be the champ with it's mix of carbides & flexibility. i bookmarked this one.great info guys.
dennisstrickland
 
Ah, but what about free chromium? Typical stainless steels in cheaper knives don't really have any level of wear resistance worth noting, but they are still pretty brittle for the most part.
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Too low carbon content, or bad heat. There are some pretty low carbon stainless steels with 13-15% chrome that are plenty tough. Some of them react almost like carbon steels with toughness and edge stability. ( 12C, 13C, Aus 6, etc. )


M4 is really about as close to perfection as I've ever seen in a folding knife, with corrosion resistance being the only real downside(I don't really need 3V/A2 class toughness in a folder). I'm thinking that a nitrogen alloy steel might be the answer. It's said that vanadium carbides form easier than other carbides, and so I would think it's safe to assume that the same can be said for vanadium nitrides. With the currently developing powder metal technology these days, it might be possible to make a wear resistant steel with a high volume of vanadium nitrides for wear resistance, while only having a bare minimum volume of chromium for corrosion resistance
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I certainly agree about M4, and like M2 as well. When it comes to Nitrogen and nitrides replacing carbon I'm pretty much at a below beginner level. Much to learn there. I do know that though H-1 is not exactly my favorite blade material it is pretty amazing stuff. I don't know what the future holds, and how much more we will see.
 
My pleasure Dennis. I've learned a bunch from your posts and try to make sure I always read them. You're pretty pragmatic, and tell it the way you see it.

If you can't learn something new here everyday you're not paying attention. That's my feelings. I've got a long ways to go and consider myself a mere beginner.

It's fascinating stuff.
 
Hi Mastiff, do you feel there is a better knife steel than CPM-3V? Seems Fehrman is making all of their knives out of it!

Bulldog Pup!

Thank you,

BabyJWuu :)
 
Hi Mastiff, do you feel there is a better knife steel than CPM-3V? Seems Fehrman is making all of their knives out of it!
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I don't think there is a best steel. They are just different steels designed for different things. Everybody's needs and likes differ, so what's good for you might be lousy for me. The same with knife designs and knife companies themselves.
 
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