Lamiated VG-10 and carbon migration issues?

Macchina

Macchina

Joined
Apr 7, 2006
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I was reading up on laminated steels and a thought occurred to me: How do we know some of the caron doesn't leave the VG-10 when you sandwich it between two slabs of carbon-hungry 420J2 (Fallkniven's recipe). Carbon likes to distribute itself when steel is above recrystalization tempurature, which is pretty low (tempering occurs in this range at 400-1000 F). Laminated steel is brought above recrystaliztion temp when it laminated, heat treated, and tempered. That's a lot of chances for the carbon to move from the 1% concentration in the VG-10 to the 0.3% concentration in the 420J2. Also, to form Chromium carbides in the 420J2, more carbon is needed and will move from the steel crystalline structure during tempering.

My point is, has anyone ever tested to see if the VG-10 core retains its 1% of carbon to satisfy it's needs for martensite and alloy carbides, or does enough of it move to the carbon-hungry 420J2 slabs during all that heating?
 
I doubt that there is 'all that heating' and possible carbon diffusion. When custom makers make damascus there's a lot of time at temperature so it can be noticable but the VG-10 is made in a steel mill with minimal time at high temperature.And the center of the VG-10 would not have any problem at all I'm sure.You could always ask Fallkniven on their forum !
 
I should add to this thread that I am not saying laminated blades are bad, just wondering about the checmical changes that occur when you laminate steel.

I own and use a few laminated Fallkniven's (because of their design, not because of their materials) and couldn't be happier with their performance. Having said that, I still don't understand what a laminated blade gets you. I don't need additonal strength (all my Fallknivens are pretty thick) and -VG10 is plenty corrosion resistant.
 
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michaelmcgo said:
I should add to this thread that I am saying laminated blades are bad, just wondering about the checmical changes that occur when you laminate steel.

I own and use a few laminated Fallkniven's (because of their design, not because of their materials) and couldn't be happier with their performance.
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I think you meant to say, you're NOT saying laminated blades are bad.

Kevin
 
michaelmcgo said:
I should add to this thread that I am not saying laminated blades are bad, just wondering about the checmical changes that occur when you laminate steel.

I own and use a few laminated Fallkniven's (because of their design, not because of their materials) and couldn't be happier with their performance. Having said that, I still don't understand what a laminated blade gets you. I don't need additonal strength (all my Fallknivens are pretty thick) and -VG10 is plenty corrosion resistant.
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mete said:
I doubt that there is 'all that heating' and possible carbon diffusion. When custom makers make damascus there's a lot of time at temperature so it can be noticable but the VG-10 is made in a steel mill with minimal time at high temperature.And the center of the VG-10 would not have any problem at all I'm sure.You could always ask Fallkniven on their forum !
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mete is a degree'ed metallurgist with a lifetime of experience. If he says carbon migration is not a problem, that's good enough for me.

The lamination buys you improved toughness.
 
knarfeng said:
mete is a degree'ed metallurgist with a lifetime of experience. If he says carbon migration is not a problem, that's good enough for me.

The lamination buys you improved toughness.
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That was my understanding. You can have a thin hard core with a soft sandwich around the outside.
 
I'm not sure if i'm being backwards and stupid but if i want a soft tough knife, i'll buy a soft tough knife, if i want a hard knife for cutting, i'll buy a hard knife.
I have seen laminated blades come apart.
 
Vicarious Reality said:
I'm not sure if i'm being backwards and stupid but if i want a soft tough knife, i'll buy a soft tough knife, if i want a hard knife for cutting, i'll buy a hard knife.
I have seen laminated blades come apart.
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Laminated blades made by who? I haven't seen any laminated blades by a reputable maker fall apart.
 
Vicarious Reality said:
I'm not sure if i'm being backwards and stupid but if i want a soft tough knife, i'll buy a soft tough knife, if i want a hard knife for cutting, i'll buy a hard knife.
I have seen laminated blades come apart.
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I don't think you understood the topic properly.
If you did, then your supposition is correct.
 
Vicarious Reality said:
I'm not sure if i'm being backwards and stupid but if i want a soft tough knife, i'll buy a soft tough knife, if i want a hard knife for cutting, i'll buy a hard knife.
I have seen laminated blades come apart.
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Vicarious Reality said:
http://www.youtube.com/watch?v=aQfOY09CEaQ&feature=related
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Let's see:
After pounding it through a chunk of steel using a a 3 pound hammer to beat on it,
This with a blade he had managed to fracture with some other "testing",
He then is able to delaminate it by putting the end in a vise and pulling with his full weight.

Even Noss thinks this knife is as tough as anything else he has tested.

Yes, your initial supposition is quite correct, no maybe about it.
 
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i think the title of that video Vicarious Reality has linked too says it all.

"Fallkniven DESTRUCTION Test....."
 
^What happened with the laminated blade was impressive.

Only one layer broke, leaving two layers left that could still be used. I don't see how anyone can put a negative spin on that. If a single layered blade had a fracture, it may have broken completely in half. Who knows?
 
The Government said:
^What happened with the laminated blade was impressive.

Only one layer broke, leaving two layers left that could still be used. I don't see how anyone can put a negative spin on that. If a single layered blade had a fracture, it may have broken completely in half. Who knows?
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+1 :thumbup:

And, if I'm not mistaken, that's the true design advantage of a laminated blade. They make laminated glass windshields for cars for the same reason. Yes, they break, but they do so with much more controlled and LESS VIOLENT results.
 
Obsessed with Edges said:
So this is the 'proof' that laminated blades come apart?

The only 'proof' I see, is how gullible some people are in believing this is a legitimate test of a knife blade. How many blades WON'T break under this kind of abuse?

File this under 'Knife Tests for Dummies'...
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i somewhat agree and somewhat disagree with you about the value of destruct testing.

while i would never routinely abuse a blade like they do in these tests, i find it of great interest to see how various blade steels perform under these sorts of "out there" scenarios.

if i was in a true survival situation where my choices were A: abuse and possibly break my knife OR B: die. i'll take option A thank you.
 
sambo. said:
i somewhat agree and somewhat disagree with you about the value of destruct testing.

while i would never routinely abuse a blade like they do in these tests, i find it of great interest to see how various blade steels perform under these sorts of "out there" scenarios.

if i was in a true survival situation where my choices were A: abuse and possibly break my knife OR B: die. i'll take option A thank you.
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While I understand your thinking, the problem arises when the uninformed assume that every knife must be totally indestructible or else it's worthless. Our reality friend is a case in point.
 
sambo. said:
i somewhat agree and somewhat disagree with you about the value of destruct testing.

while i would never routinely abuse a blade like they do in these tests, i find it of great interest to see how various blade steels perform under these sorts of "out there" scenarios.

if i was in a true survival situation where my choices were A: abuse and possibly break my knife OR B: die. i'll take option A thank you.
Click to expand...

No argument there. When it comes down to life or death, I'd do the same. My only beef here is that some seem to look at a 'test' like this, and then deem a knife somehow 'inferior' because it broke. Very few of us will ever have the luxury of being in possession of the ideal, indestructable tool (knife or otherwise), when we're suddenly and unforseeably confronted with a life-or-death situation. We'll use whatever we have on us at the time.
 
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