Steel carbide makeup

dkb45

dkb45

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Dec 16, 2012
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I'm curious about what carbides makeup common steels. Diving more into data about carbides and abrasives, I'm learning that many abrasives are not really suitable for steels with certain carbides, namely vanadium.

I know steels with over around 3% vanadium have a large number of vanadium carbides, but what about steels like S35VN and Elmax which are under that threshold? CTS-XHP? ZDP-189? Is D2 mostly chromium carbides?
 
Hey . . . looks like everybody is out playing Frisbee or motocrossing or some such.
I just got up and noticed your predicament.

You might go over to the Maintenance, Tinkering and Embellishment forum and look at the stickies at the top of the page such as this one :
Link >>>> https://www.bladeforums.com/threads/steel-faq.368828/#post-3325212

Also the Crystal Weaving thread here (if you want the real high tech aspect; prepare to have your brain rewired) Great thread !!! :
Link >>>> https://www.bladeforums.com/threads/heat-treatment-crystal-weaving-foundation.1409721/
 
dkb45 said:
I'm curious about what carbides makeup common steels. Diving more into data about carbides and abrasives, I'm learning that many abrasives are not really suitable for steels with certain carbides, namely vanadium.

I know steels with over around 3% vanadium have a large number of vanadium carbides, but what about steels like S35VN and Elmax which are under that threshold? CTS-XHP? ZDP-189? Is D2 mostly chromium carbides?
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The carbide volume of S35VN is found in its datasheet: https://www.crucible.com/PDFs\DataSheets2010\dsS35VNrev12010.pdf

Elmax has very little vanadium carbide due in part to its high chromium content. It is primarily chromium carbides. XHP and ZDP-189 are also a relatively large volume of chromium carbides.

D2 has approximately 15.5% chromium carbide volume after heat treatment as shown in this patent: https://patentimages.storage.googleapis.com/36/0f/e3/6aa98edaa4eec4/US5830287.pdf
 
Larrin said:
Don’t read the Crystal Weaving thread.
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A knife maker that cuts nails in half many times in one go with his thin hand made heat treat sample, with no edge damage, deserves to be listened to.

His knives are VERY THIN and perform splendidly.
NOW . . .
why, pray tell, wouldn't one want to hear what he and others have to say about the fine points of alloys and heat treating them?


There are many fine videos at this link. >>>>>> BlunCut MetalWorks
THANK YOU Blunt Cut !
 
Wowbagger said:
NOW . . .
why, pray tell, wouldn't one want to hear what he and others have to say about the fine points of alloys and heat treating them?
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I will provide two reasons:
1. The thread you linked is not about carbides in steel which is what the OP requested information about.
2. The author of the thread you posted is a charlatan who makes up pseudoscience. Even addressing him to this extent gives him more attention than he deserves. Whether his knives perform well or not doesn’t matter if the goal is to learn about the science of steel.
 
Does molybdenum form carbides in steels like 154cm and CPM-154, or is 154cm/CPM-154 also mostly chromium carbides?
 
Larrin Larrin ,

I have yet seen other maker runs the same steel at same hardness & profile and able to do what he does with similar extent of damages. Empirically it works.

It’s unfortunate no one else took his sharing (check the early part of his thread) CWF HT and did the test to prove or disprove his theory, challenge him to improve his theory or drop it altogether. Because no one does, we’re left with Luong solo enhancement rather than many making progress together. :(
 
Chris "Anagarika" said:
Larrin Larrin ,

I have yet seen other maker runs the same steel at same hardness & profile and able to do what he does with similar extent of damages. Empirically it works.

It’s unfortunate no one else took his sharing (check the early part of his thread) CWF HT and did the test to prove or disprove his theory, challenge him to improve his theory or drop it altogether. Because no one does, we’re left with Luong solo enhancement rather than many making progress together. :(
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Testing of the knives or method is separate from the “metallurgy theory” he proposed which is based on nothing.
 
Larrin said:
Testing of the knives or method is separate from the “metallurgy theory” he proposed which is based on nothing.
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He is able to do that by following his theory. Until now, I have not read anyone no coming forward and use the method he shared & said it failed to produce the expected results. (I’m lacking resources and tools to try myself).

Or pointed out where his mistakes are by doing the same process and share a better theory on why that process works. Until then, since it works and no other better theory, what else is there to use in advancing the knowledge? I’d love to hear experts take on this and not simply say he’s charlatan.

I think at this point we just have to agree to disagree. I lack the metallurgy background that probably you have, so I take it as he shares openly, he’s trying to advance current metallurgy. Probably you have enough background to say he’s charlatan, but until a better theory explaining why CWF 1.0 he shared works (or proof it doesn’t), I’d give him the benefit of the doubt. No more comment on this and apologize to OP for sidetracking the thread.
 
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Chris "Anagarika" said:
He is able to do that by following his theory. Until now, I have not read anyone no coming forward and use the method he shared & said it failed to produce the expected results. (I’m lacking resources and tools to try myself).

Or pointed out where his mistakes are by doing the same process and share a better theory on why that process works. Until then, since it works and no other better theory, what else is there to use in advancing the knowledge? I’d love to hear experts take on this and not simply say he’s charlatan.

I think at this point we just have to agree to disagree.
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You have it backwards. The theory doesn't lead to anything, because it is made up. It is a fabrication created to sell knives and the corresponding heat treatment process.

charlatan: a person falsely claiming to have a special knowledge or skill; a fraud

Since he has falsely claimed to have special knowledge about a fake metallurgical theory he fits the exact definition of a charlatan. He could have made up a theory that magical fairies make the steel warp space-time, but that wouldn't mean that we should go with it until a better theory is found.

I pointed out many of his mistakes and false claims and he didn't change any of his claims. I even described potential phase transformations that would occur during his supposed special heat treatment. I would argue that I approached his claims more seriously than anyone. More seriously than they deserve to be approached, in all honesty.
 
Larrin said:
Thermodynamic calculations predict chromium carbides only, with some amount of molybdenum enrichment. This has been confirmed experimentally: http://knifesteelnerds.com/2018/03/16/micrographs-of-niolox-cpm-154-and-aeb-l/
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I finally got around to reading this, and it was actually really interesting. I did not expect both AEB-L and CPM-154 to be so crazy uniform with their carbides, and didn't expect Niolox to be so refined. If what I read was correct, all 3 steels are predominantly chromium carbides with very small traces of other carbides, and Molybdenum doesn't form any carbides in the matrix, just makes molybdenum rich chromium carbides?
 
dkb45 said:
I finally got around to reading this, and it was actually really interesting. I did not expect both AEB-L and CPM-154 to be so crazy uniform with their carbides, and didn't expect Niolox to be so refined. If what I read was correct, all 3 steels are predominantly chromium carbides with very small traces of other carbides, and Molybdenum doesn't form any carbides in the matrix, just makes molybdenum rich chromium carbides?
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I try to make all of my articles interesting. :) AEB-L gets its uniform carbides through careful alloy design and processing, while CPM-154 is primarily because of the powder metallurgy process. Niolox was actually more coarse than I expected. You are correct that CPM-154 doesn't have any molybdenum carbides, but there is some molybdenum-enrichment of the chromium carbides. High speed steels with their higher molybdenum and lower chromium will actually form a molybdenum carbide.
 
Alright new question concerning vanadium carbides. I know steels with 4% or more vanadium make large vanadium carbides and therefore generally operate best with a toothy edge and respond best to diamond abrasives, but what about steels with less, like Elmax, Cru-Wear, and S35VN? Do those also have the large vanadium carbides just in smaller quantities?

I know 3% is the sweet spot where conventional abrasives don't give you a weakened edge (at least when you use diamonds for reprofile and sharpening, corundum for honing), and over that gives (me at least) rolling when cutting highly abrasive media along with accelerated loss of keen edge.
 
dkb45 said:
Alright new question concerning vanadium carbides. I know steels with 4% or more vanadium make large vanadium carbides and therefore generally operate best with a toothy edge and respond best to diamond abrasives, but what about steels with less, like Elmax, Cru-Wear, and S35VN? Do those also have the large vanadium carbides just in smaller quantities?
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Elmax and S35VN are powder metallurgy steels so they behave somewhat differently than conventional steels, though Cru-Wear can be conventional or PM. The size of carbides in powder metallurgy steels is primarily controlled by the amount of carbide, and Elmax and S35VN both have much more chromium carbide than vanadium carbide, so the carbide size is controlled by the chromium carbides not really the vanadium carbides.
I know 3% is the sweet spot where conventional abrasives don't give you a weakened edge (at least when you use diamonds for reprofile and sharpening, corundum for honing), and over that gives (me at least) rolling when cutting highly abrasive media along with accelerated loss of keen edge.
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Rolling of edges is not controlled by the carbide volume but by the yield stress, read this article for more information: http://knifesteelnerds.com/2018/03/13/why-doesnt-heat-treating-affect-steel-flex/
It has been reported that a high carbide volume leads to more rapid loss of the initial edge, but Elmax and S35VN would both be considered high carbide volume steels, despite having lower vanadium content than 10V for example.
 
I mean that doesn't necessarily answer my question. Like how I know with moderate percentages of molybdenum they form molybdenum carbides in carbon steels, but with high chromium too they make molybdenum enriched chromium carbides (like in 154cm), does vanadium act similarly at under 4% and over 4%?

I know under and over 4% behave differently because steels 4% and over have given me a lot of rolling of the apex when stropped with abrasive softer than the vanadium carbide, except K390 which seems to just follow its own rules. S30V, S90V, S110V, and M390 have all shown significant rolling when an abrasive other than diamonds is used for honing, but using a full diamond setup I experience little to no rolling, the little I get could be easily attributed to inclusions in cardboard.

I'm mainly wondering why steels at and over 4% vanadium have to be treated specially to perform like super steels, while steels under 4% behave like they should without any special treatment.
 
Vanadium is a stronger carbide former than molybdenum so it is more likely to form vanadium carbides than to enrich other carbides. Niobium and titanium are even stronger carbide formers.

Abrasives don’t cause edges to roll so I’m not really sure what you are referring to.
 
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