Steel carbide makeup

Larrin said:
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.
Click to expand...
I have determined that what is likely the cause of the rolling I've been experiencing is softer abrasives weakening matrix holding the harder carbides in on high vanadium steels (as they cannot abrade the vanandium carbides, they only abrade the softer matrix). Sharpening and stropping with diamonds virtually eliminated the issue for high vanadium steels.

I'm asking about the difference between more and less than 4% vanadium steels is because I've had no issues with Cru-Wear, Elmax, and S35VN rolling using corundum or AlOx to strop, so that would lead me to assume that less than 4% vanadium causes a significant difference in carbide structure, possibly in the formation of vanadium enriched chromium carbides instead of outright vanadium carbides.

I just think it's extremely odd that Elmax and M390 act so differently when they are so similar. I'm really curious how both look on the micrograph side by side.
 
dkb45 said:
I have determined that what is likely the cause of the rolling I've been experiencing is softer abrasives weakening matrix holding the harder carbides in on high vanadium steels (as they cannot abrade the vanandium carbides, they only abrade the softer matrix). Sharpening and stropping with diamonds virtually eliminated the issue for high vanadium steels.
Click to expand...
That is an odd hypothesis, I would need more evidence to accept that.
I'm asking about the difference between more and less than 4% vanadium steels is because I've had no issues with Cru-Wear, Elmax, and S35VN rolling using corundum or AlOx to strop, so that would lead me to assume that less than 4% vanadium causes a significant difference in carbide structure, possibly in the formation of vanadium enriched chromium carbides instead of outright vanadium carbides.
Click to expand...
Both Cru-Wear and S35VN have approximately 3.5% MC carbides (either vanadium or niobium). Elmax with its higher chromium content doesn't form much in terms of MC carbide.
I just think it's extremely odd that Elmax and M390 act so differently when they are so similar. I'm really curious how both look on the micrograph side by side.
Click to expand...
Neither Elmax or M390 form much MC carbide, the main difference is carbide volume; M390 has more.
 
If he says he has discovered some new way if heat treating steel he should
1- patent it
2- publish it
3- let others make independent galidation
4- study his new steel structure (electron microscopy and other fancy methods)


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. 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.
Click to expand...
 
Revolverrodger said:
If he says he has discovered some new way if heat treating steel he should
1- patent it
2- publish it
3- let others make independent galidation
4- study his new steel structure (electron microscopy and other fancy methods)
Click to expand...

He let go no. 1, did no. 2 & 3 through his heat treatment thread (anyone can try the method) and trying to do 4 (anyone wants to fund the laboratory cost?).
 
Check out Spyderco's catalogue (you can download it). It has an excellent section on alloying elements, various steels and a whole bunch more knife stuff.
 
Larrin is right of course and that's why you never see me on certain threads. !
BTW a recent ad , for the same steel , is noted as Cb and in another section as an Nb steel. We old timers laugh at that
, the rest of you are stuck with a girly steel !
 
It's great having professionals here and contributing. Thanks!

D2 and 440C. Both are chrome carbides. One a pretty tough ingot steel and one not so tough. The Chrome is obviously much higher in 440C but D2 has higher carbon which usually means less tough. Is carbide volume the largest difference maker or is it something else like the added vanadium in D2. Also, why can one work at rc 62 while the other can't. Thanks.

Joe
 
D2 only has marginal toughness; it's toughness is highly overrated. 440C doesn't have the carbon in solution to easily make 62 Rc after a reasonable heat treatment. Therefore it has to be overaustenitized, undertempered, or both to achieve 62 Rc where its toughness is poor.
 
Metal Experts - please make sure show your emperor stuff/clothe first then maybe think about bad mouthing others. For example - show us your 64+rc chopper in aeb-l or more challenging niolox, such as this one:


Simple - if you can't do something others can, which mean others know and experienced something you simply don't have! i.e. time to learn.
 
Larrin said:
D2 only has marginal toughness; it's toughness is highly overrated. 440C doesn't have the carbon in solution to easily make 62 Rc after a reasonable heat treatment. Therefore it has to be overaustenitized, undertempered, or both to achieve 62 Rc where its toughness is poor.
Click to expand...
I've actually seen a lot of experts say the opposite, that D2 is considered a low toughness steel by many, but when done right is far more tough than most applications would need (unless you are blatantly abusing your knife, even super tough steels like 5160 have limits), granted the key phrase is when done right. 60-62 HRC is obviously not the HT for a tough D2 knife, but I've had no issues at all with D2 ran hard as a folder steel, it's tougher than ceramic, which is about all a folder needs.
 
dkb45 said:
I've actually seen a lot of experts say the opposite, that D2 is considered a low toughness steel by many, but when done right is far more tough than most applications would need (unless you are blatantly abusing your knife, even super tough steels like 5160 have limits), granted the key phrase is when done right. 60-62 HRC is obviously not the HT for a tough D2 knife, but I've had no issues at all with D2 ran hard as a folder steel, it's tougher than ceramic, which is about all a folder needs.
Click to expand...
I didn’t say it doesn’t have enough toughness for your intended use, I said its toughness is marginal. It is in the same category as several stainless steels or 10V. All of which have sufficient toughness for many applications. The reputation of D2 fluctuates throughout the years because it has been in use for so long, but for a long time it has been promoted as a “semi-stainless” that offers similar performance to carbon steels, tool steels, or whatever the flavor of the month is while having some stain resistance. The truth is that it behaves similarly to many stainless steels while having much lower corrosion resistance. That is due to its high fraction of large chromium carbides. Therefore even if it is a “good” version of a steel with many large chromium carbides, it is still in the same category as the others.
 
bluntcut said:
Metal Experts - please make sure show your emperor stuff/clothe first then maybe think about bad mouthing others. For example - show us your 64+rc chopper in aeb-l or more challenging niolox, such as this one:


Simple - if you can't do something others can, which mean others know and experienced something you simply don't have! i.e. time to learn.
Click to expand...

So if I have a video of my knife chopping a dead fall tree I have right to claim my superior magical metallurgy? I believe most people here know any proper steel with decent HT can do that.

To be honest, I used to be a fan of your experiment years ago till you came up with the BS super quench and now these silly CWF?

Actually its not difficult to prove your theory.. just have a third person with some qualifications do it for you. Brad at Peters would be interest to inspect your workpiece. You said once you spent thousands of dollar inventing these magical way to heat treat, why dont just spent a little more to publicly verify it instead making poor quality video chopping a wood...

Until that I don't even believe when you declare the hardness of your knife.
 
When selling a product with declared hardness to a customer, it MEANT: In USA - Legally I am liable for this product, honor its declared attributes (includes HRC). So, proof is your burden, otherwise your assertion is baseless.

shqxk said:
...
I don't even believe when you declare the hardness of your knife.
Click to expand...
 
shqxk said:
A first person in this video is my friend. His knife is made of 304 stainless but with our special heat treatment we can made it into 68HRC and after these competition it was even sharper than beginning , the secret is quenching in the unicorn pee. Is that make sense?
Click to expand...


No , it not make sence ! WHY all of you metal experts don t accept his challenge ?????????????????????????

Metal Experts - please make sure show your emperor stuff/clothe first then maybe think about bad mouthing others. For example - show us your 64+rc chopper in aeb-l or more challenging niolox
Click to expand...
 
Guys, if you aren't going to talk about steel makeup, please stop fighting. I've learned a fair bit from this thread and don't want it shut down for petty squabbling.

Still have no idea why steels above 3% vanadium act so differently than steels at or under 3%. Knowing very little about metallurgy I would guess it has to be that over 3% is past the threshold for vanadium carbides to form, but below they tend to combine into the matrix or other carbides, kinda how molybdenum works in 154cm, chromium is a stronger carbide former so it bonds to chromium carbides instead of forming its own.
 
My apology for OT to defend my works.

Sharpening against vanadium & composite carbide volume% is more relevant than composition mass%. Example1: Vanadis 4E 3.7%V formed around primary 7% VC volume with avg diameter around 2um, which is low in particle/carbide count, thus particle spacing (3D spatial/space) is sparse enough for abrasive(non cbn/diamond) cutting tips/edges to fairly easy to plow the matrix. Example2 : While S30V 4%V would forms around total around 13% (more than half is VC), now carbide shielding (the matrix) crossed over the threshold where abrasive getting dull (riding & impacting carbides) faster than plowing matrix because of carbide spacing is narrow (narrower than steels with lower carbide volume).

Keep in mind, if avg carbide dia is 1um, then carbide count is 8 times relative to 2um carbide dia. So spatial shielding actually will dull fine soft abrasive a lot faster than steel with 2um carbide. Of course matrix strength inverse proportional (just pull a factor out of thin air would be fine) abrasive digging depth.

Dulled abrasives (ceramic or very strong bond AlO/SiC) will burnish/polish the steel, unless using crazy pressure to induce plowing affect (also could fracture /micro-crack the apex).

dkb45 said:
Guys, if you aren't going to talk about steel makeup, please stop fighting. I've learned a fair bit from this thread and don't want it shut down for petty squabbling.

Still have no idea why steels above 3% vanadium act so differently than steels at or under 3%. Knowing very little about metallurgy I would guess it has to be that over 3% is past the threshold for vanadium carbides to form, but below they tend to combine into the matrix or other carbides, kinda how molybdenum works in 154cm, chromium is a stronger carbide former so it bonds to chromium carbides instead of forming its own.
Click to expand...
 
You must log in or register to reply here.
Back
Top