Question About Thin INFI:

[Iboschi]

Sandgrouper, LVC, 230,

Gentleman you all knocked this out of the box and I appreciate your weighing in. I agree INFI isn't magic, but it is kick-ass. My original intent with this post is to better understand the properties of INFI on thinner grinds. We all know how INFI performs on fat choppers. I wanted to know more about what can and cannot be done with thinner ground INFI.

230,

Your episode with the CF SarSquatch is what first brought to my attention that the thinner INFI has behaves differently than we observe in thicker grinds. Without that field test, I would never have been interested in thin-INFI and it's properties.

Sandgrouper,

If you have the ability to test INFI as discussed, but require a "test -subject" perhaps something could be arranged. The accumulated INFI on this board is enough to buy a kingdom, I'm sure we can find some for analysis. What do you think?

LVC,

Enlightening post as always. You must have some of these awesome posts bookmarked, at least in your mind, to be able to dredge them from the depths like that. I'm still new here, but try to soak it up. As to the content of your post. That is indeed good news. It supports what I've read to be the case. Thanks for taking the time to post and link solid info from "The Man".

 

[PeterPHWS]

Great thread and thanks to those who spent time on their posts :thumbup:

You never stop learning on here ....

 

[Iboschi]

Great thread and thanks to those who spent time on their posts :thumbup:

You never stop learning on here ....

Amen. I really appreciate the depth of the answers on this thread rather than the general "It's a frigging knife, it will cut what you need to cut" answers. As much as thin INFI is an AMAZING steel, I almost wish Busse would release other knives in different steels that are more suited to other applications than chopping and thick unbreakable knives (pry-bars if you like), which INFI is best suited for. A different steel with a different purpose in mind might not be TERRIBLE. Jerry is known not only for INFI but his heat treatment on ALL the steels he uses.

As I read this, it feels wrong somehow. Blasphemous even. I know INFI is nearly un-breakable and really won't fracture. That is part of why Busse is able to provide the warranty they do. Using other steels MIGHT lead to problems, but then it might not. Well, I'm going to post this anyway just to see where this trail of breadcrumbs leads. Thinking outside the box is how INFI came to pass in the first place. How many knife makers think "This steel isn't doing the trick for me, I'll just make-up my own"?

 

[sandgrouper]

Thanks Last Visible Canary, I have to say that I really loved Cliff's work, if not always his personal style, its how I ended up here in BF and this forum in particular. And I always find 230grains experiences particularly educational, and PeterPHWS's and William.M's come to that.

I don't have the facility to perform stress-strain testing where I work, although I fairly regularly deal with people who do that for a living. I am sure that I could scrounge up enough to get a couple of samples together, especially as these folks specialize in miniature samples for assessing the service related degradation of things like steam pipes and turbine blades and discs.

BUT, and it is a big BUT, much as I would like to be able to look up one of my handbooks and get a complete rundown on all the mechanical properties of INFI, I have to be honest and say I wouldn't post them in public.

LVC's post demonstrates very clearly once again that Jerry is not just making this up as he goes along. He has worked hard at it and developed a profound understanding of the properties of the materials he works with, beyond the standard, text book treatments. You only do this through your own experimentation and testing. I am sure that he has all the information on the necessary properties through his own work. If he wanted it widely spread, I reckon he would have done it. It is his work, his business, for me he can run it as he chooses. Others take a different view, but I figure that it looks as though the people who work for him are enjoying their work. They are making an honest living. They can run the operation however they please and it is up to the rest of us as to whether we want to support that or not.

Like I said in my first post, I love to have numbers to plug into equations and see what happens and these are numbers that I would love to have. However, it just doesn't feel right to me.

I am more than happy to use what general knowledge I have of materials and how they work when loaded to inform anyone's thinking about what may or may not make sense from the start. I find it helps me and am glad if it helps anyone else.

As to Busse using other metals where it is appropriate; I think they do, they just call it Swamp Rat or Scrap Yard. I have a couple of thin bladed Swamp Rat slicers in D2. I have mid-sizers and choppers in S7 and 52100 from Scrap Yard and Swamp Rat. I don't yet have any 154CM from the Busse group, but I will pick one up one day. These are all good choices for their purpose with slightly different mixes of compromise, so the choices are there. Not every choice, but I am not the first to say (and it is plain from the published data as well as experience) that you are miles better off with something a bit less exotic that has had a thorough and carefully thought out and executed heat treatment than the most whiz-bang new steel with a careless or less deeply informed treatment program. Even something like 1095 can end up at 58 Rc with wildly different properties depending on how you get it there.

 

[tomthebaker]

what is this thin infi you speak of. never seen it.

 

[Last Visible Canary]

Thanks Last Visible Canary, I have to say that I really loved Cliff's work, if not always his personal style, its how I ended up here in BF and this forum in particular. And I always find 230grains experiences particularly educational, and PeterPHWS's and William.M's come to that.

most of my knowledge of infi has come from cobalt's explanations of the microconstituant interactions like why infi is near stainless because of it's low carbon to chromium ratio, leaving free chromium in the matrix. nearly everything else regarding the physics side has come either directly from cliff or from the discussions he started. But a lot of people are unwilling or unable to let small things go. even when cliffs info was without citation or backing documentation, the logic was there, and it was very educational. I wish he was still here.

the working knowledge has come from cliffs physical work, a small bit from notz (sp? the russian guy who did the string tests), noss, 230grain, and the various others who have broken, caused damage too, and done testing of the various bussekin knives.

a big part of nondestructive testing is the visual inspection. it's the first source of knowledge and information about the break, and why it broke that you get. even if the post contains no information whatsoever other than "it broke while prying" or "I was chopping wood at night and this happened", if the image is high enough resolution it's a valuable source for understanding the steel and how it reacts to the stresses likely to occur during that type of action. people who post breaks often get a lot of flak, both for breaking the knife and for posting about (the idea being it will "hurt the companies image"), but every time I see a break image it peaks my interest.

 

[Last Visible Canary]

more info about what busse/bussekin can do with d2.

In regards to your other inquiry, I am not at liberty to disclose our specific heat treating protocol, but I can tell you that we are able to maintain a continuous quench that takes our D-2 tool steel down to -300 degrees below zero. This is done in a dry atmosphere over the course of nearly 70 hours, which includes the slow trip back up. We will perform a minimum of three oven tempers and our very specialized heat treating protocol takes over 80 hours to complete. In studies performed by one of the pioneers of dry, slow cycle, deep cryogenics, D-2 experienced in excess of a 1,000% increase in tool life.!!! We agree that the secondary curve offers greater toughness. That's all I can say for right now. Thanks for your interest.

Jennifer

from
http://www.bladeforums.com/forums/showpost.php?p=2153338&postcount=6

sadly, most of the pics in this thread are now doa. I saved them when they were posted, but I've since lost that hardrive

Here are the pics from the some of the testing we did on the Bog Dog and the Safari Skinner. Both of these knives had a Rockwell hardness of between 61-62. Remember that D2 is not supposed to have much lateral strength at that high of a Rc. Also it would normally chip out with extreme impacts to the edge as it is more of a cutter not a high impact steel.

As the pictures show, the Bog Dog has a significant flex and the Safari Skinner pics were taken after a 275 lb Deputy Sheriff spent 1 1/2 hrs pounding on it with a hammer. The edge has rolled but is not chipped out like you'd expect (and even more important it isn't in pieces) and you can even see the area on the side of the blade where it was impacted with the hammer. When finished the hardened face of the hammer actually had gouges in it from the knife. These pics show that we have achieved a large amount of malleability of the edge(which is uncommon for D2)

Also some makers don't think that D2 performance can be increased by a deep cryo treatment, I think that these tests prove differently. We have done testing on most of the other D2 blades out there from many many makers and none of them come even close to this level of toughness or durability.

We do these tests so you don't have to
In the past, we have probably been overly cautious when discussing the abilities of our D2 blades, but now you can really see what they can do. We get this type of performance because of our proprietary Heat treat and deep cryo cycles.
However, please don't try to break them just so you can say you did.

Toughest D2 blades on the planet
http://home.insightbb.com/~e.isaacson/bog_dog_flex.jpg
http://home.insightbb.com/~e.isaacson/Skinner_beating.jpg

http://home.insightbb.com/~e.isaacson/Skinner_Beating3.jpg

http://home.insightbb.com/~e.isaacson/Skinnerbeating5.jpg

How did the edge of the Bog Dog look after the bend test?

At this point, when the picture was taken, the edge was undamaged (uncracked) and the blade would return to true. We did continue to bend it to destruction and at that point the blade had taken a set, which in itself is unbelievable because D2 normally will not take a set but will just break(and break with very little bend).

I hope this helps

Actually we are not just saying that's what we did we are actually showing you we did it in the pictures that are posted. That's one reason we post the pics, a lot of people can say there knives perform, few actually show you that they do.


The face of the hammer! The spine of the knife was placed on the anvil with the edge up. Then the edge was pounded with the face of the hammer. I hope that helps.

from
http://www.bladeforums.com/forums/showthread.php?t=322561


I agree that the other steels should be placed with the other companies. Busse is the flagship of harduse in the bussekin set, and that requires the hardest use steels. and a skinner from scrap yard is much much cheaper :thumbup:.

 

[Iboschi]

more info about what busse/bussekin can do with d2.



from
http://www.bladeforums.com/forums/showpost.php?p=2153338&postcount=6

sadly, most of the pics in this thread are now doa. I saved them when they were posted, but I've since lost that hardrive









from
http://www.bladeforums.com/forums/showthread.php?t=322561


I agree that the other steels should be placed with the other companies. Busse is the flagship of harduse in the bussekin set, and that requires the hardest use steels. and a skinner from scrap yard is much much cheaper :thumbup:.

LVC, and SG,

I think you're both right about using other materials within Busse Kin companies rather than Busse Combat. I would like them to use D2 on a couple of slicers though. Perhaps even see some Busse Combat designs on some Swamp Rat or Scrapyard knives. We've seen some come close to crossing over.

LVC,


I hadn't read or seen any of that before. You sir, are a veritable fount of knowledge, although we already knew that. I'm not surprised that they pushed D2 into unknown territory. If there is even more info you have handy to link, I am enjoying the information. Did the cryo treat of D2 change the properties in other ways also? Are there any unintended consequences or effects that are undesirable?

 

[Last Visible Canary]

I hadn't read or seen any of that before. You sir, are a veritable fount of knowledge, although we already knew that. I'm not surprised that they pushed D2 into unknown territory. If there is even more info you have handy to link, I am enjoying the information. Did the cryo treat of D2 change the properties in other ways also? Are there any unintended consequences or effects that are undesirable?

http://www.angelswords.com/cryo_basics.php

that link is only about 3-4 pages long and gives a good intro to cryo.

The basic idea is to get every last bit of the austenite in the steel to turn into martensite, something that can't happen with higher carbon steels at room temperature. it's my understanding that austenite is a face centric crystalline structure. In most steels that use the austenitic formation (pans, utensils, other stainless applications) the face centric formation is stabilized by nickel atoms replacing the iron atoms in the crystal. Since d2 doesn't have nickel, the austenite in it is unstable and will break down at room temperature. chromium and molybdenum (which d2 has) help to destabilize it even more. so, to avoid your crystalline structure collapsing into less desirable structures, you want as much of it to turn into martensite as possible. (in d2 and other nickel free high Cr Mo Si steels)

The second benefit of cryo is the refinement of carbides. d2 is known for having big 5 micron carbides that tear out on thinner edges. It's theorized that the low temperatures reduce the ability of carbon to make a covalent bond with other carbon atoms, so you have a slowed rate of carbide formation. By making the carbides smaller you reduce the tear out effect and you reduce the disruption of the martensitic grain structure.

I haven't heard anyone say anything about cryo being detrimental to knife performance. It's just a question of how much it's going to help a given steel, there are times when it's not worth the cost for the small gains you get, but with d2 you get pretty big leaps in performance.

 

[Iboschi]

LVC,

Even more great info. Thanks for taking the time to respond and explain it in your words as well. Understanding steel is rewarding. The process is significantly more complex than I had initially imagined.