S30V disadvantages?

mete said:
" Grain refinement through dislocation density increases' NO it doesn't happen.
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What part doesn't happen? Forging doesn't induce a dislocation density increase, or that dislocation density doesn't effect grain size? Both of these are well known solid state physics properties.

When you plastically deform metals there are dislocations induced in the crystal structure, these are cites of nucleation during crystal changes and the more sites the lower the grain as grain growth is inversely related to nucleation rate.

Cryo does not refine grain either !!
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It is argued for mainly in regards to enhancing toughness, hardness, and wear resistance.

Some makers get really good results with it, such as what Swamp Rat has done creating D2 blades which show high levels of ductility and impact toughness at a high hardness.

Some makers like Busse, Wilson, Johnson and others have tried various cold treatments and found them to be of benefit, and they are open about the performance about their knives and their testing.

I would appreciate material journal references which contrast tool steels with and without cryo and show no advantage to the multiple tempering approach.

-Cliff
 
The only disadvantages to S30V is that it is hard to work, generally can not be sharpened in the field as easy as say, 0-1, and is fairly brittle. S30V for a big chopper is not reccomended.
 
Working metals produces dislocations .However with a knife, after forging you normalize or anneal which removes the dislocations.....I said cryo does not reduce grain size. By the time you get to the Mf temperature the martensitic grains are already formed and no further change in grain size occurs.There may be other changes though at this point in time only reduction in retained austenite is established despite many claims.
 
Well I will throw my 2 cents in on this, though I do not claim to be a metallurgist.

I have knives in both S30V and D2 and I prefer the D2. Both do any cutting task I could ask or expect of a knife. I prefer the D2 because of ease of sharpening. I too have heard some stories from 2 people in the industry where S30V chipped during testing. Both of them claimed it was probably due to the heat treatment. This was also early on in S30V's debut so I would also chalk it up to makers still learning about it's properties.

With all the new technology out in steels and heat treating even old stand-bys like 440C and 1095 are benefiting. Until they develop the steel where you never need sharpening again, you will still eventually have to sharpen it.
 
No problems so far.

http://www.benchmade.com/products/product_detail.aspx?model=921

Here is a link about various steels. You must remember that the steel is only one of many variables that go into making a good knife. You shouldn't blame the steel for a crappy knife. The design, heat treatment, grind, etc. all have much to do with the final quality. There are many many good knife steels. I don't think you can objectively compare blades unless they come from the same maker and are the same model and used for the same purpose.

Some folks forget that knives are not (1) screwdrivers, (2) nail pullers, (3) axes, (4) saws (except for a couple of Leatherman), (5) hammers, etc. etc. and they wonder why their blades chip and get dull!

http://www.ajh-knives.com/metals.html
 
Cliff Stamp said:
I knew I read this several times but it took awhile to track it down, here is one of the examples :

http://www.crucibleservice.com/datash/S30Vvs440C3.pdf

It specifically promotes S30V as being easier to heat treat than 440C which is a common high end stainless knife steel.

-Cliff
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In addition to your evidence, it is interesting that Crucible says high hardness is greater than 56. Not sure if there is an "official" meaning to high or low hardness other than relative or if that is just what Crucible chose as the number.
 
I've been carrying a Spy Native 2 in S30V and so far it's been OK, gets only the occasional box to cut, nothing major, maybe a few envelopes. It's been in use for maybe 6 mos. now and is definitely not as sharp as when I got it. I thought it would stay sharper than what it is since I don't go crazy using it.

I left it on me when I spent a few hours in the pool. Didn't rinse it off and the next day there were some tiny rust spots but they came off with a bit of mmy fingernail.
 
dulaboy said:
I've been carrying a Spy Native 2 in S30V and so far it's been OK, gets only the occasional box to cut, nothing major, maybe a few envelopes. It's been in use for maybe 6 mos. now and is definitely not as sharp as when I got it. I thought it would stay sharper than what it is since I don't go crazy using it.

I left it on me when I spent a few hours in the pool. Didn't rinse it off and the next day there were some tiny rust spots but they came off with a bit of mmy fingernail.
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The edge itself could have corroded, even if you can't see it with your eyes. This would make it dull.
 
Carl64 said:
In addition to your evidence, it is interesting that Crucible says high hardness is greater than 56. Not sure if there is an "official" meaning to high or low hardness other than relative or if that is just what Crucible chose as the number.
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It is two years ago, i talked with one guy from Böhler about S30V and the promotion. He wasn´t impressed by the properties at just 58.

It is always sad that Crucibles information lacks a clear sight. You always get your eyes turned on seperated points, never get a whole view.
 
conan said:
#1. Crucible did not promote CPM S30V as easy to heat treat. Key word - PROMOTE
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Scott, Cliff is the God of steels and is never to be questioned! I wrote the same comments to him and he set me straight. How dare you question him! You may have been one of the developers of S30V but that means nothing! You may have also worked on the S30V marketing plan, but that also means nothing! :rolleyes:

Mete, you may make your living as a metallurgist, but how can that compare to Cliff? You foolhardy mortal! If Cliff writes, "Grain refinement through dislocation density increases", we will rewrite the laws of physics so Cliff is right! :rolleyes:

I hope the followers of Cliff now can see him for what he is. Scott Devanna is the VP at Crucible, the company that makes S30V. If Cliff can misrepresent (lie) about the marketing of S30V, how can you believe him on anything else? Mete is a professional metallurgist. Cliff plays loose with the facts and when caught bloviates* until the opposition goes away.

Cliffs latest bloviation*, S30V is easy to heat treat because Crucible said it was easier than 440C! Who said 440C was easy to heat treat? Compare 440C to 1084. 440C is much more difficult.

Put Cliff on your Ignore List. BladeForums is a much better experience without him.

*(blo·vi·ate)n. To bloviate is to speak loudly, verbosely, and at great length, without saying much.

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Chuck Bybee said:
If Cliff can misrepresent (lie) about the marketing of S30V, how can you believe him on anything else? Mete is a professional metallurgist. Cliff plays loose with the facts and when caught bloviates* until the opposition goes away.
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The document seemed pretty clear to me. Is 440c especially hard to heat treat? I would like to hear opinions on what it means to be easier than 440c. Crucible must have said it for a reason.

Cliffs latest bloviation*, S30V is easy to heat treat because Crucible said it was easier than 440C! Who said 440C was easy to heat treat? Compare 440C to 1084. 440C is much more difficult.
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That's the comparison Crucible chose. Gripe at them.

*(blo·vi·ate)n. To bloviate is to speak loudly, verbosely, and at great length, without saying much.
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Funny you should swing that word around. Your latest post is back-handed insults with very little real content. Cliff's latest post was mostly just pointing to a Crucible document, possibly one of his shortest posts.
 
Carl64, after our last discussion I thought there was hope for you. Now your being a whiney. Taking quotes out of context, making comparisons that don't mean anything. What is your next trick, bloviation?
 
mete said:
Working metals produces dislocations .However with a knife, after forging you normalize or anneal which removes the dislocations.....
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Yes, however the arguement is that the dislocations induce a finer grain size in the states produced. Thus after forging and normalizing you get a finer grain size than with bar stock directly which induces finer grain size in the subsequent martensite. There is even an arguement for repeating heat treatments to further refine grain size based on this behavior. Fowler has cited lab grain size measurements on his 52100 which support the arguement that more forging work produces finer grain size. Have you checked out that data?

By the time you get to the Mf temperature the martensitic grains are already formed and no further change in grain size occurs.
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It is also stated to temper the martensite directly and induce changes in carbide structure, which based on tracing down dozens of references seem to go back to one paper, but as yet I have seen no retractions, or direct published refutations.

Plus the Mf temperature for many high alloy steels is way under the elevated oil/air quench temps influence the grain size formed. As well there are makers using it which get performance in the steel beyond hardness, such as the toughness of Swamp Rat's D2.

Carl64 said:
...it is interesting that Crucible says high hardness is greater than 56.
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From a sheer volume arguement this would hold. The number of people who would consider 60 HRC to be soft is rather low. If you check on the metals or wood working newsgroups for example they will recommend 440A over 440C for knives (if someone asks for suggestions) because 440C is way to hard to grind.

Chuck Bybee said:
Who said 440C was easy to heat treat?
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Who lists it as one of the most demanding? I have never heard any maker refuse to heat treat it, unlike say S90V which Bos won't do as the temps are too high.

-Cliff
 
Quit arguing with Cliff. All he's trying to do is get to 10,000 posts and you are all playing into his game.
 
Cliff Stamp said:
Yes, however the arguement is that the dislocations induce a finer grain size in the states produced. Thus after forging and normalizing you get a finer grain size than with bar stock directly which induces finer grain size in the subsequent martensite.
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How much of that is due to forging and how much is due to normalizing and other thermal-only adjustments? If you took a stock-removal blade and performed the same heat-treatments, I don't think you'll see a different result.

Cliff Stamp said:
There is even an arguement for repeating heat treatments to further refine grain size based on this behavior. Fowler has cited lab grain size measurements on his 52100 which support the arguement that more forging work produces finer grain size. Have you checked out that data?
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Is that from more forging or more post-forging normalizing? I'm not sure you'll ever see a performance-based advantage from either method. If you had field knife CNC ground from an Angus Trim design and had another forged as close to that design as possible by someone else and then had a third party perform all post-forging post-grinding heat-treatments in an identical manner, I think you'd only see an advantage from the forged knife if it was just off enough from Mr. Trim's design to match your esthetic likes closer.
 
Satrang said:
Quit arguing with Cliff. All he's trying to do is get to 10,000 posts and you are all playing into his game.
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Is there a knife for free, if you hit it?
 
thombrogan said:
How much of that is due to forging and how much is due to normalizing and other thermal-only adjustments?
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Good question, many like Fowler argue it is the hammering but I don't recall if he ever compared the results of just heat cycling it the same amount. I would like to see a maker included who spent as much time on stock removal heat treating so you were comparing optimal in both methods, R.J. Martin or Phil Wilson. Have them do the heat treatment on the stock removal blank with their ideas on how to opomize it for whatever tests it was required to perform. Or just take a piece of SR101 from Swamp Rat forge that into a blade and grind a Camp Tramp and do a comparison against the regular stock removal piece, that would also be informative.

If you had field knife CNC ground from an Angus Trim design and had another forged as close to that design as possible by someone else and then had a third party perform all post-forging post-grinding heat-treatments in an identical manner, I think you'd only see an advantage from the forged knife if it was just off enough from Mr. Trim's design to match your esthetic likes closer.
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I would not bet otherwise, but would really be interested in seeing that done. A lot of the time you see references to improvements but not specifically exactly how much. Assuming all the grain refinements do happen, how much does this translate to wear resistance, ductility, impact toughness, etc. . The knives keep changing as well which complicates the matter obviously as does the makers skill with the tests so the knives tend to improve performance wise even if the steel stays the same.

Blop said:
Is there a knife for free, if you hit it?
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Yes, the Covert Delaminator by Dark Ops.

-Cliff
 
To each his own, but If i needed steel advice I'd rather take it from a knifemaker, not a "knifetester". we have heard it all before in the many, many posts that have degraded to noninformative trivial debate.
S30v vs D2 vs next super edge holding rc 2000 steel..who cares! lets get some perspective here! there are professional guides, climbers, hikers, hunters, outdoorsman, soldiers..people who actually use knives that get buy with Buck's 420hc or Vicorinox's stainless. lets all just get whatever we like that works for us, not some wondersteel that some "knifetester" tells us is superior. Makes me wonder who the sheeple really are.
 
davmgt said:
S30v vs D2 vs next super edge holding rc 2000 steel..who cares!
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It's odd that you are even reading threads like this. Are you really that bored that you read threads so obviously about something you don't care about?
 
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