Are CPM ( Powder Steels ) More prone to chipping?

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Ankerson said:
With .30% Vanadium and the low percentage of Carbon there is no way that any Vanadium at all is being formed into carbides, there just isn't enough carbon nor Vanadium in the steel.

Carbon .46%
Chromium 13.00%
Silicon .40%
Vanadium .30%
Manganese .40%

...maybe 1% or 2% at the very most Chromium carbides and that is stretching it....
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Just because the percentages are low, that doesn't mean none are formed. Low percentages can lead to low formation. What is your basis that zero form?

How was the percentage of Cr carbides arrived at?
 
me2 said:
I wouldn't call that impact toughness related either. That's more a ductility issue, and again, strength, and geometry. Impact is at the speed of being hit with a hammer, say if you were chopping into the cardboard. I don't think just cutting it is fast enough to be impact. You can certainly cut cardboard and hit an inclusion, and push on through it. If the edge isn't hard enough (strong enough), then the inclusion can deform the edge and break the deformation off. This will look like a chip, but it's not impact related.
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Ok gotcha. So toughness correlates more to holding up to impact versus just dead weight?
 
Buck_110 said:
Just because the percentages are low, that doesn't mean none are formed. Low percentages can lead to low formation. What is your basis that zero form?

How was the percentage of Cr carbides arrived at?
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There has to be a min of .50% to .75% of an alloy in the matrix to form carbides and the Carbon percentage has to high enough to help form the carbides, if they are lower than that they are called trace elements and go to grain refinement.

At 13% Chromium and .46% Carbon only 1 or 2 percent at most will be formed into carbides, the rest goes to corrosion resistance.

The alloy content just isn't there.
 
Ankerson said:
There has to be a min of .50% to .75% of an element in the matrix to form carbides and the Carbon percentage has to high enough to help form the carbides, if they are lower than that they are called trace elements and go to grain refinement.
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Ankerson said:
At 13% Chromium and .46% Carbon only 1 or 2 percent at most will be formed into carbides, the rest goes to corrosion resistance.
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Then why is C able to form carbides at a percentage concentration of .46%?

What are these percentages based on?
It's more than simply the percentages of Cr and C which are present that determine the percentage of Cr carbide formation.
I suppose a guesstimation can possibly apply if only Fe, C, and Cr are the only elements present.
Add more elements to the steel's composition, and how can carbide concentration be determined without examination of the finished product? Different heat treats are also a factor to consider.
 
Buck_110 said:
Then why is C able to form carbides at a percentage concentration of .46%?

What are these percentages based on?
It's more than simply the percentages of Cr and C which are present that determine the percentage of Cr carbide formation.
I suppose a guesstimation can possibly apply if only Fe, C, and Cr are the only elements present.
Add more elements to the steel's composition, and how can carbide concentration be determined without examination of the finished product? Different heat treats are also a factor to consider.
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The percentage of Chromium carbides can be adjusted by the tempering process and final HRC hardness.

The other elements like Vanadium are tied into the Carbon content, but if the percentages aren't high enough to form the carbides they won't.

Just because a steel has Vanadium in it doesn't mean that that Vanadium is being formed into carbides.

Seems like you are trying to make 420HC sound like more than it really is for some reason......
 
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BG42EDGE said:
Would you be more comfortable if the comparison was with ATS-34? Or BG-42? Or D2? Or INFI?
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I am comfortable with my steels as it is. And for that matter, if you go back, searching articles before S30V came about, you will find enough reports of ATS-34/154CM chipping(my own complaints included). Now, before you about there's more links about S30V, let me remind you, back than internet wasn't as widespread as it was later. And again, majority of the chipping reports were from early days of S30V, which was disappointing in many areas. But even then, if you got custom S30V blade, which had proper HT, there was no chipping issue.

For the record, 154CM what was chipping for me was around 60-61HRC, later on Phil Wilson rehardened another 154CM blade for me, 62HRc, reground high performance, thin edge. No chipping and edge holding is a huge improvement, plus much better cutting performance. So, there you go, more magic, thinner, harder edge doesn't chip, while thicker, softer edge did chip, same steel...

BG42EDGE said:
Because the result is still the same. Huge numbers of reports on S30V chipping.......not on the others.
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S30V aside, you do realize that a single steel(improperly heat treated at that) can not be used to make a statement that all PM alloys have chipping issues and there is a vast conspiracy to promote inferior steels...
 
Gator97 said:
I am comfortable with my steels as it is. And for that matter, if you go back, searching articles before S30V came about, you will find enough reports of ATS-34/154CM chipping(my own complaints included). Now, before you about there's more links about S30V, let me remind you, back than internet wasn't as widespread as it was later. And again, majority of the chipping reports were from early days of S30V, which was disappointing in many areas. But even then, if you got custom S30V blade, which had proper HT, there was no chipping issue.

For the record, 154CM what was chipping for me was around 60-61HRC, later on Phil Wilson rehardened another 154CM blade for me, 62HRc, reground high performance, thin edge. No chipping and edge holding is a huge improvement, plus much better cutting performance. So, there you go, more magic, thinner, harder edge doesn't chip, while thicker, softer edge did chip, same steel...


S30V aside, you do realize that a single steel(improperly heat treated at that) can not be used to make a statement that all PM alloys have chipping issues and there is a vast conspiracy to promote inferior steels...
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Exactly, the HT and tempering process has everything to do with how any steel will perform.
 
Gator97 said:
....you do realize that a single steel (improperly heat treated at that) can not be used to make a statement that all PM alloys have chipping issues....
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How do you know that the incredibly high numbers of reports of S30V chipping were on improperly heat treated knives?

Hmmmmm.......? Who told you that?

Could it have been...............SATAN????

:D

Or maybe the knife manufacturers?

;)
 
BG42EDGE said:
How do you know that the incredibly high numbers of reports of S30V chipping were on improperly heat treated knives?

Hmmmmm.......? Who told you that?

Could it have been...............SATAN????

:D

Or maybe the knife manufacturers?

;)
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It's much easier to blame the steel than it is to blame themselves in the end. ;)

That is the bottom line on S30V.

Done properly it's an excellent steel.

Spyderco is the only Company that will come out and say we screwed up and fix the problem. ;)

Sal Glesser is a stand up guy and there is a lot to be said for that kind of integrity. :)
 
That is the bottom line on S30V.

Done properly it's an excellent steel.
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Again, How do you know that the incredibly high numbers of reports of S30V chipping are on improperly heat treated knives?

I've asked that question a lot.....

:)
 
Ankerson said:
The other elements like Vanadium are tied into the Carbon content, but if the percentages aren't high enough to forum the carbides they won't.
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How are they tied in?

Ankerson said:
Just because a steel has Vanadium in it doesn't mean that that Vanadium is being formed into carbides.
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Nor does it mean it will not. It depends on which elements are present.

Ankerson said:
Seems like you are trying to make 420HC sound like more than it really is for some reason......
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It has nothing to do with 420 HC at all, actually.

The atomic mass of each element will determine carbide concentrations. Heavier elements are more stable than lighter elements. As atomic mass increases, so does the element's stability.
The carbide formers in 420 HC are V and Cr.
V has an atomic mass of 50.9415
Cr has an atomic mass of 51.9961
Since the atomic mass of V is less than that of Cr, it is less stable and bonds more readily. After the V is depleted from forming vanadium carbides, the Cr will follow. Chromium carbides will be formed until there is no more available carbon to bond with the chromium. The Cr that doesn't form carbides will remain as free chromium.

Carbon .46%
Chromium 13.00%
Silicon .40%
Vanadium .30%
Manganese .40%
 
Ankerson said:
Sal Glesser is a stand up guy and there is a lot to be said for that kind of integrity. :)
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The guy quoted here?

Reply 5: S30V - "Steel of the Devil?"
Michiel Vanhoudt replied 3 months, 3 weeks ago
I said it was the steel of the devil. Even at highly refines state it micro chips. The steel is hyped and really not that good. Sal Glasser said: S35VN is what s30v should have been if they only designed it for knives. s30v chips easily, doesn't hold a refined edge, is expensive and overhyped. that's the problem
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http://boardreader.com/thread/S30V_Steel_of_the_Devil_avjmnXjii0.html

I agree with him.
 
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Gator97 said:
And again, majority of the chipping reports were from early days of S30V, which was disappointing in many areas.
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People are still reporting S30V chipping......apparently there's still plenty of disappointment.
 
BG42EDGE said:
People are still reporting S30V chipping......apparently there's still plenty of disappointment.
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That would be either Idiot users or Bad HT, you pick. ;)

I would lean towards the 1st more than the 2nd.
 
CrimsonTideShooter said:
A lot of what people report as "chipping" is really rolling and denting. People as a whole aren't knowledgable enough to know the difference.
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A lot of that is also that aggressive toothy working edge that S30V gets once they start to use it, a lot of people think that is chipping.
 
Buck_110 said:
How are they tied in?



Nor does it mean it will not. It depends on which elements are present.



It has nothing to do with 420 HC at all, actually.

The atomic mass of each element will determine carbide concentrations. Heavier elements are more stable than lighter elements. As atomic mass increases, so does the element's stability.
The carbide formers in 420 HC are V and Cr.
V has an atomic mass of 50.9415
Cr has an atomic mass of 51.9961
Since the atomic mass of V is less than that of Cr, it is less stable and bonds more readily. After the V is depleted from forming vanadium carbides, the Cr will follow. Chromium carbides will be formed until there is no more available carbon to bond with the chromium. The Cr that doesn't form carbides will remain as free chromium.

Carbon .46%
Chromium 13.00%
Silicon .40%
Vanadium .30%
Manganese .40%
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Not enough alloy content is the bottom line. ;)
 
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