THE question...

"The toughest metals for knives are busse's infi steel, cpm3v, bg42 ands30v. Of these cpm3v is supposed to be the toughest at the expense ofcorrosion resistance and needing a little more work resharpenning butwith twice as long edge retention as most other steels. Busse's infisteel, a nitrogen rich steel, is supposed to have the best tradeoff intoughness to corrosion resistance and easily sharpenning, and S30v issupposed to be a great balance as well. BG42 may be stronger than S30vas this was the steel in the older sebenza's and many complained whenReeve's switched over to s30V because s30v needs to have a lowerrockwell hardness than bg42 and many said that this is a reflection ofthe steel's relative weakness to BG42. If you buy any other steel youdo so to save money on your purchase for that is the only benefit ofthe other steels. "
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Forgive me, but I just couldn't hold my tongue. I'm not sure where this quote originally came from, but I would not go by it. For one thing, the toughest knife metals CERTAINLY DO NOT INCLUDE STAINLESS STEELS! I'm sorry, lost it there for a minute. Also, the list is far longer than 3V and INFI....5160, L6, and S7 come to mind for example. Don't get me wrong, there is some merit to the quote, but I don't want to give a newbie a false metallurgic foundation.
 
Forgot to add, the last statement is particularly absurd :(

Again, not trying to step on anyone's toes! :D
 
the quotes i quoted came from a search on google.com for "infi steel"
i do not take credit for any of it. i am very knowledgable in the metallurgy business as i designed the apollo space vehicles but when it comes to infi it beats the hell out of me:confused:
 
Originally posted by oliverplomion
What does make INFI so much better than many other steels? :D
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I think the answer is twofold:
1) the chemical composition, especially the nitrogen which forms very hard nitrides;
2) the heat & cryo treatment.

For more info, see: INFI

Gene
 
Yeah and Oli....you oughta buy a beer for all those nice folks helping you out here!
I'll take one too for not trying to help!:D :p
 
Whaddya doin, training for Blade??

You forget to turn off the lights and go to sleep last night??

Oli, c'est le tout. (Hope that's right, been almost 30 years bro..)
 
hahahahahahahahahaha merci Mike!

hehehehehehe it seem like french language and french girls are a trade on this forum!:D I can suply! Girls for INFI!!! Ouch...I have to take care we're not in the trade section:rolleyes:
 
Originally posted by Andrew Lynch
Forgive me, but I just couldn't hold my tongue. I'm not sure where this quote originally came from, but I would not go by it. For one thing, the toughest knife metals CERTAINLY DO NOT INCLUDE STAINLESS STEELS! I'm sorry, lost it there for a minute. Also, the list is far longer than 3V and INFI....5160, L6, and S7 come to mind for example. Don't get me wrong, there is some merit to the quote, but I don't want to give a newbie a false metallurgic foundation.
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I do not pretend to know anyting about INFI or why it is as good as it is, but I do know metallurgy as that was my engineering field background as well as heat treatment which leads me to believe that the heat treatment is in a large part responsible for the performance of INFI. In fact heat treatment is responsible for any steel being good or bad. Not all ATS-34's are the same. I would be more likely to trust an ATS-34 from a known entity than one done to save money. Hence all the bad RAP 440 stainless has gotten in the past, undeservedly so. I agree completely with Andrews assessmet of good steels and I would add many more to that list, just about all of them being carbon steels not stainless, unfortunately. 52100 is another favorite custom tough steel. The A series of steels can be very tough, and A-2 has a good reputation in that regard. O-1 is a great steel until you chrome plate it.:D (Chrome is not a vapor barrier and hence will not provide any effective corrosion resistance.) This has been explained in detail in the past and no need to go into it here, you search archives if you wish.

As for S30V, it is supposed to be 3V with Chromium added which would make it more corrosion resistant. I agree that it cannot be as tough as 3V or even other tough carbon steels like 5160, or A-2. But it might be the toughest SS out there, not sure if anyone has bothered to compare. It sure is being used in big knife applications. But I would not sacrfice 3V for S30V in a large blade. I'd rather maintain my equipment than settle for less.
 
Quote from Jerry Busse: "As for INFI and temperature extremes, it is amazing. INFI is tempered at nearly 950 degrees. It does not begin to lose any significant hardness until it is held above 1050 degrees for a considerable amount of time. I have to believe that it would need to be extremely mishandled in order to do any noticeable damage.

Most of the simpler high carbon steels (of which INFI is NOT a member) can be drawn down in temper in a matter of seconds if the temperature hits above 500 - 800 degrees. Along the thin edge of a knife, a buffer or dremel can produce this level of heat and can cause serious damage if not executed by a professional. Always check the grade of steel and heat-treat specs. before assassinating it with the dremel tool Uncle Leo gave you for Christmas. Always keep the steel cool to the touch and you should be fine."

More INFI INFO coming, soon.

--Mike
 
Originally posted by Evolute
Quote from Jerry Busse: "As for INFI and temperature extremes, it is amazing. INFI is tempered at nearly 950 degrees. It does not begin to lose any significant hardness until it is held above 1050 degrees for a considerable amount of time. I have to believe that it would need to be extremely mishandled in order to do any noticeable damage.

Most of the simpler high carbon steels (of which INFI is NOT a member) can be drawn down in temper in a matter of seconds if the temperature hits above 500 - 800 degrees. Along the thin edge of a knife, a buffer or dremel can produce this level of heat and can cause serious damage if not executed by a professional. Always check the grade of steel and heat-treat specs. before assassinating it with the dremel tool Uncle Leo gave you for Christmas. Always keep the steel cool to the touch and you should be fine."

More INFI INFO coming, soon.

--Mike
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If anyone can hold a blade that is at 900 degrees, let me know:D
 
Quote from Climber:

"Some Technical Details...
Although INFI is not considered "stainless" by the arbitrary standard by which metals are judged, which is "higher than 15% Chromium" or "higher than 14.5% Chromium" or "higher than 12% Chromium" or whoever you're asking... Yet it DOES what "stainless" is SUPPOSED to do: Retard Corrosion. What really makes something "stainless" or stains less than standard carbon steels??? A good amount of FREE Chromium is ONE method, the most common. Free Chromium inhibits bonding by "outside influences" beyond the metal matrix itself. But to GET to that stage where the Chromium is "freed up" ah, there's the rub. Carbon "locks up" 17 times its weight in Chromium, under normal circumstances, & no other factors involved; which there sometimes are... (Hey, you want a SIMPLE answer? Then ask a simpler question! Ha, Ha! )
So if a steel has 1 full % of Carbon, it would 'normally' require 17% of Chromium to bond with the Carbon, producing Chromium Carbides -- good hardness qualities, good wear resistance, good toughness as benefits --BEFORE any FREE Chromium can do any real benefit in the 'stainless' or Corrosion Resistance department. 440C is around 1% Carbon, & usually 18% Chromium; hence it is a good corrosion-fighter: It has at least as much "remaining" Chromium after Carbon-bonding as there was Carbon to begin with...
An effective ratio for Corrosion Resistance.
Some others, like D2 are less in Chromium (14.5%) & more in Carbon ~1.4%, so it has far less corrosion resistance: i have a D2 sword rusting away right next to me here, just from the humid Nebraska air... (it's an handmade experiment, OK? )
So 'steels'(NOT!) like Stellite, Talonite, & BDC, have a Cobalt Matrix, TONS (Well: 28%-32%) of Chromium! Corrosion-Proof? Time will tell, but it probably will not tell in our lifetimes! Now, if you complicate matters, & i hinted that we would, add a little Vanadium to "THE MIX" and the Carbon is all over that! It bonds well to Vanadium, and it bonds well to other elements. So that decreases the amount of Carbon that is bonding to the Chromium, thus freeing up them little Chromium guys to "patrol the borders" if ya know what i mean! (Cor~ Res~) So also an amount of Molybdenum "frees up" Chromium, keeping them little greedy Carbons from sucking up all that Chromium!
So, Now, lets look at INFI: REALLY look at it...
This stuff is DESIGNED TO BE AMAZING, and it is amazing: here's just part of why:
INFI has less than 1% of Carbon, about half a percent actually; & 9% Chromium. Do the Math: 0.5% Carbon bonding with 17 times its weight of Chromium = 8.5% Chromium used as Chromium Carbides, leaving a remainder of 0.5% Chromium; which is as much as the Carbon was to begin with: so, same RATIO as 440C, a known, proven "Rust-Fighter." Also, wouldn't you know it, there's Vanadium AND Molybdenum AND Nickel AND Cobalt in that thar piece of INFI Steel ! So, there's actually a LOT more free Chromium runnin' 'round the Matrix than our math-formula suggests, as Carbon atoms bond with those other elements. Oh Yeah: Not to mention NITROGEN, which changes and enhances the bonding in more ways than i currently can spew...
Enormous Toughness; flexibility, metal-memory, hardness properties retained & not subdued, wear resistance maximized, STRENGTH beyond the legendary Wootz(!) etc, etc.
THEN: there's the heat treatment: Transversion-Wave HT... But it's a Secret: Shhh... Let's just say that Heat Treat is still the most important factor, which is why INFI is the most Advanced Steel we can commercially buy...
Enuf already!"

---------------------------------------------------------------------------------------------

Cobalt, as the quote from Jerry exemplifies, there are certain situations which might cause part of a knife to be greatly heated, while the rest remained bearably cool. This is particularly true because some Busse knives are well over a foot long. I can hold the backmost part of a handle while the tip is heated to 900 degrees.

Anyway, it is just one of several ways in which INFI provides a broader scope of possible use and potential to withstand stress while remaining undamaged.

--Mike
 
Quote from Cliff Stamp: "I examined the corrosion resistance of M-INFI several times and each time was impressed with the results. The first time I just left the blade covered in a 1/2 litre of water for 3 and a half hours. This however failed to induce visible rusting or make any impact on the slicing ability. Making the environment a little harsher I put it back into the water and poured a tsp of salt across the
blade. Five and a half hours later the blade was examined and a three very small rust spots were found, being about 1 to 2 mm across. The edge did not feel significantly different. Ten hours later the blade was examined and no additional rusting was evident. The slicing ability still had not significantly degraded. All rust was then removed easily with a Scotchbrite pad and the edge restored to the x-coarse finish.

Making the environment a little harsher and including the TOPS Steel Eagle for reference
(1095), I put both blades in a steel pan. Each knife was covered with water (3/4 litre) and 2 tsp of salt was poured along each blades. After five hours the TOPS blade was covered in rust along any non-coated area (as expected) and the slicing ability of the blade was cut almost in half. The edge on the Basic was not effected and the blade showed little effect from the soaking except for
a few light rust spots along one side of the bevel (the side facing the metal pan). The rust on the Basic was removed when the blade was dried, the only resulting effect was a few water spots visible along the bevel. The TOPS blade still had rust remaining after drying (much was removed though) as some parts of the blade are engraved and ground out (blood groove and such) and escape contact while drying. Interesting enough, the TOPS blade formed a lot of black rust as well, this was not present at all on the Basic. After drying the blades were again exposed to a corrosive environment.

This time determined to effect the Basic I poured a mixture of salt and water (2 tbsp per 8 oz) over each blade, put both in the metal pan and then added an additional 8 oz of the salt water. This left the blade exposed to the air as well as the water and I hoped the movement of the air would induce
rusting faster. After 4 hours I checked on both blades and this seemed to be evident. The TOPS blade was again completely covered, with corrosion, mainly black rust though as I never removed much of it from the last soaking. The Basic had some spots along the spine and the bevel. When the cutting ability was checked a significant difference was noted in both blades.

Based on that it would seem to me that you would need a fairly corrosive enviroment in order to worry about functional degredation due to rust. I have not seen any in actual use."

--Mike
 
Quote from Jerry Busse: "Stainless? Not supposed to be. However, INFI has demonstrated very high levels of stain resistance in many different climates. Uncoated blades have been tested for more than a year in Alaska and have made their way into the wilds of British Columbia, the High Sierras and the tropical rain forest. No rust in Alaska or British Columbia! No rust in the High Sierras, even when exposed to great quantities of blood and left in the wet grass overnight. The tropical rain forest, which has been known to rust plastic (just kidding), did offer the toughest of the environmental exposures and a light speckling of oxidation did occur but was easily removed in the field with a hand rubbing of sand and water. No pitting was reported. Now I'm sure that salt-water exposure would offer some different results. The point is that although INFI is not a stainless it is certainly not a rust aggressive steel as many of the high carbon steels have proven to be. Couple this with our coating and you've got yourself a fairly
maintenance free knife."

--Mike
 
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