INFI, is tough steel?

SpyderPhreak said:
Jack hammer bit steel is tougher, but corrodes quite readily. One of those is called S7. Swamp Rat and (especially) Scrapyard used that steel with the Busse heat treat protocol, and called it SR-77.

INFI is a steel that's all about compromise. It is extremely tough (there ARE tougher), and fairly corrosion resistant (but not quite stainless), while still being able to take and maintain a really good edge. It is easy to sharpen too. Any other questions? :D
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when i saw the D-test videos by NOSS , i found that the SR77 is more prone to cracking than INFI under heavy impacting ,

so i got that toughness is not only factor here to make a tough knife , there are other factors like strengh & edge staybility combined togher to make a knife less prone to fail & break.

steel quality from the factory is also a big pro here , same bunch knives & under the same procedure of HT, why there are lemons , why others are normal ?
 
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dingy said:
when i saw the D-test videos by NOSS , i found that the SR77 is more prone to cracking than INFI under heavy impacting ,

so i got that toughness is not only factor here to make a tough knife , there are other factors like strengh & edge staybility combined togher to make a knife less prone to fail & break.

steel quality from the factory is also a big pro here , same bunch knives & under the same procedure of HT, why there are lemons , why others are normal ?
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I do believe that INFI is tougher than S7 at the same Rc.
 
steel quality from the factory is also a big pro here , same bunch knives & under the same procedure of HT, why there are lemons , why others are normal ?[/QUOTE]

The reasons for variation could be the oven is hot or cold in spots, thickness of material could vary slightly, kill coating from steel manufacturing may not have been fully removed, nitrides not fully applied, could be someone leaned on a grinder too hard or didnt use the right cooling technique. Truthfully there are a million potential reasons for lemons. The only true way to find out is to conduct failure analysis on every failure.
 
Since Nitrogen is no longer in INFI, do we now call it IFI ?:D
 
Cobalt said:
Guy, you do not have to destroy a blade to determine the composition. It can be done without destruction. I can test any blade any time with no damage. It must be bare steel though.

And I did verify a while back that the composition had changed. I just wonder where OP got his data from since I never published anything, but I have not been on the forums and it may have been in some thread.
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I did recently stumble across an old (2009?) discussion regarding the INFI composition. Can't remember if it was here in teh Busse Forum or another. The guy who runs the Z-knives site (gator?) chimed in, asking the OP for a copy of the metalurgy results so it could be added to the steel chart.
 
resinguy said:
I did recently stumble across an old (2009?) discussion regarding the INFI composition. Can't remember if it was here in teh Busse Forum or another. The guy who runs the Z-knives site (gator?) chimed in, asking the OP for a copy of the metalurgy results so it could be added to the steel chart.
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interesting. That z-knives site is still around? Cool. I think his name was Rodney? oh well. I have the results as well. Slightly different but that is not unusual, There is a bit of an error when doing testing.
 
THT's correct...as far as knife steel goes, INFI is by far the easiest I've ever dealt with sharpening...

THE EASE OF SHARPENING by itself is a terrific selling point...

NOW add to that all the other well-balanced qualities INFI possesses...

IMHO, Busse has made it easy to choose when KNIFE USERS go shopping for steel
 
Jerry tries to pass himself off as a regular guy that just makes cool knives. The fact is that he is a genius. He has probably done more research in the field of Heat Treat and steel chemical composition than any other modern knife maker and the proof is in what he has done. He actually made his name with his A2 and D2 knives. He has more knowledge locked up in that scotch filled head of his than most books do between the binders. He could heat treat a turd and make it cut.
 
People want to baby the old A2 knives, hell, that's what the reputation was built on. Those Steel Hearts are insanely tough!!!
 
The addition of nitrogen to steel does some amazing things. It is used for armor on vehicles (tanks), for instance. Heat treat can be tricky from what I read, but Busse reputedly has developed a very good process. Hence INFI.
 
Alberta Ed said:
The addition of nitrogen to steel does some amazing things. It is used for armor on vehicles (tanks), for instance. Heat treat can be tricky from what I read, but Busse reputedly has developed a very good process. Hence INFI.
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Since Nitrogen is no longer in INFI I assume he figured a way around it.
 
I remember Noss did some tests on a FFBM and a Skinny ASH a few years ago. Whatever is in the steel these days is working fine.
 
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Will York said:
Was not aware. Thanks, Dennis.
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Will, it was not me, it was the OP that somehow found a post somewhere here discussing it. Also, although Cobalt and Nickel can be tested for, it could be that nitrogen cannot be. In which case it may not show up in a spectral test, but I am not sure. The numbers in OP's post add up to 1, but it could be that there are trace elements of N and cannot be seen. I have to pull my results from when I tested my FBM LE (2004?). See if the numbers match up. Not that it matters at this point. Kinda cool to see what the progression of steel is.
 
Cobalt said:
Will, it was not me, it was the OP that somehow found a post somewhere here discussing it. Also, although Cobalt and Nickel can be tested for, it could be that nitrogen cannot be. In which case it may not show up in a spectral test, but I am not sure. The numbers in OP's post add up to 1, but it could be that there are trace elements of N and cannot be seen. I have to pull my results from when I tested my FBM LE (2004?). See if the numbers match up. Not that it matters at this point. Kinda cool to see what the progression of steel is.
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I see--thought you were reporting on your own testing. Thanks for the clarification. I wondered about the accuracy of nitrogen testing with spectral analysis, also.
 
Will York said:
I see--thought you were reporting on your own testing. Thanks for the clarification. I wondered about the accuracy of nitrogen testing with spectral analysis, also.
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I don't know. I did pull my analysis just now and here it is:

2004 FBM LE

C = ? assume 0.6%, since spectral analysis does not read it.
Mn = .52% measured
Cu = .07% measured
Cr = 7.65% measured
Mo= 1.54% measured
V = 0.57% measured
Fe = remainder
No Nitrogen noted, however, that does not mean it is not there.

What is definitely not there is Nickel and Cobalt. There is no Silicon, which the 2009 test does have. So this FBM seems to be closer in all respects to the original INFI except for Cobalt and Nickel. So the 2009 version is a further development with Silicone added but less Mo.

Test was done on a niton xl2 800 xrf spectral analyzer.

I will have what I own tested. I have been meaning to test my Tamahagane blade anyway.
 
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