Friction Forged Blades : CATRA tests

Kohai999 said:
It is my understanding that Jerry hands out blanks to makers, and then Busse Knives does the heat treat on the completed blades.

Best Regards,
STeven Garsson
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He has only handed out blanks to one kifemaker to my knowledge, Churro. And yes he obviously did the HT. I guess what I am saying is that the manufacturing of INFI is also part of the secret, not just the HT and the elemental analysis. It is the entire thing, the steel, how it is made and how it is processed.

So I guess FF D2 is kinda like the stainless version of MAD DOGS O-1. MD Hard Chromes his O-1 to get a surface hardness (Rc) over 70. Except O-1 is tougher than D2, so in essence MD's knife is harder, holds an edge longer and is tougher than FFD2, right? We all know that O1 is a tough carbon steel, much tougher than any stainless steel. In fact that is one of the big problems with stainless steels, is that they are not tough.
 
This thread has answered my questions about FF.

First, Wayne you have really done a great job explaining to one such as me, how this process works, the tests you've done, and backed it up very well with real world experience and made it understandable. Thank you.

Lots of funny drama. Witty stuff, entertaining.. Nothing better than to hear it from Steven, to Cliff. The opposite of a love letter, but still good. "Go to hell, and take this, your chart with you..."

Some questions I have:
What is the amount of force applied in FF, just curious, how many thousands of pounds?
Is there a transition zone between the extremely hard edge and the soft back? (similar to differential hardening, w/ torch and multiple quench method)
What is the desired Rockwell hardness of the spine, in the knives made w/ this process?
David
 
I’m sorry to be slow answering, show time for BLADE West and all than.

The down pressure is between 8,000 and 10,000 lbs.

The back of the blade is spring tempered, not exactly what would be called soft.

I can’t be sure about the hardness of a transition zone. I’m assuming it would be quite narrow from the appearance of the blade after bead blasting, the hard part stands out real well.
 
The real test of this knife is going to be by users in the field. Six months from now I would like to see reports from people like me who have ordered the knives. I am still waiting for my Goddard model.
 
Wayne,
I am speaking in ignorance here, but as I understand the "fracturing" of the crystalline stucture of steel in forging helps promote the grain refinement, more than if it were pressed in a hydrolic vise. If this is correct, would it not be more benificial for the refinement of the grain if instead of compressing and shearing the steel, pounding the steel with the same intense force? What effect would that make? Or, would it matter at all since the Rockwell is already at such a high level?
David
 
2knife said:
Wayne,
I am speaking in ignorance here, but as I understand the "fracturing" of the crystalline stucture of steel in forging helps promote the grain refinement, more than if it were pressed in a hydrolic vise. If this is correct, would it not be more benificial for the refinement of the grain if instead of compressing and shearing the steel, pounding the steel with the same intense force? What effect would that make? Or, would it matter at all since the Rockwell is already at such a high level?
David
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David,

Per your previous question: There is a transition between the FF region and the spine of the knife. It is roughly 0.5mm wide. There is a hardness gradient from the FF zone to the spine.

The current hardness of the spine is 45 Rc. We can process any hardness, and therefore could (if desired) tailor the properties for a particular application.

The "fracturing" of the crystal structure you refer to is called recrystallization. Yes, this is what produces the refinement of the grains. The degree to which you can refine the grain is dependent on temperature of deformation, strain, strain rate, and cooling rate. At a given temperature, the higher the % strain and/or strain rate, the greater the refinement that can be achieved.

Tracy
 
I was just looking for a clarification on the grain size produced by this process. I've read 2 different sizes in various threads. One is 0.5 microns, the other is 0.05 microns. Can someone clarify which is correct?
 
me2 said:
I was just looking for a clarification on the grain size produced by this process. I've read 2 different sizes in various threads. One is 0.5 microns, the other is 0.05 microns. Can someone clarify which is correct?
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Me2,

500 nanometers (0.5 microns).

Tracy
 
Per grain size of FFD2.

There was a typo in my article in November BLADE Magazine. It was my fault because I had incorrectly typed it as .05 in my original .......so I can't blame the magazine. It should have read .5 ........this is most likely the cause of some confusion.

Wayne G
 
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