Call for Charpy toughness samples

To add what warren said, something we gotta remember is toughness is just one attribute to these steels. Aebl at 59 my be tge toughest weve seen yet but zwear eill have significantly increased wear resistance. All in what you want out of a steel
 
Larrin, thanks for the real world effort you put into all this. I wish they'd start making AEBL up to 0.30" thick, or at least 1/4" thick, though for a fighter, 4.5mm thick at this toughness level is not shabby at all. Brend used 4.5mm thick A2 for his fighters once.


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I mind of fracture grain but when you mentioned it ......it will be nice to see microstructure too.................... :)
 
Larrin Larrin , are the results from your tests (thank you very much for doing them, a huge thank you also to your father, D DevinT and to @Willie71) corroborating what you expect it would happen or is there any steel that surprised you? I confess that I’m really impressed with AEBL score!!!! I know Roman Landes (and your father) uses it for years, so I already knew it was good stuff, but tougher than lower Chromium steels like Zwear or Cruwear? Incredible! This makes me think if cpm3v is really so tough as some people think, or if it scores below AEBL! An interesting test to make, if @Willie71 has the time.
 
If a high impact test result is all that it takes to make a steel impressive I guess I'll have to do some S7 coupons too.
 
We don’t have any emotional attachment to the testing, just trying to gather information.

It’s nice that aebl is tough, I’m more interested in knife steels than shock resistant steels.

Hoss
 
I know you don't. I just don't understand the surprise at the AEB-L results. What qualifies something as a knife steel to you? S7 qualifies for me. And I'm quite curious how it tests at 58-59 RC.
 
There are always surprises in research. I thought 40CP would be more similar to CPM-154 and I thought Niolox would do better because of its relatively low carbide volume. I think we need more steels to really piece everything together. CATRA testing is more expensive but the dream would be a database of both toughness and edge retention tests to be able to show the toughness-edge retention balance of all the different major steels over a range of hardness.
 
kuraki said:
I know you don't. I just don't understand the surprise at the AEB-L results. What qualifies something as a knife steel to you? S7 qualifies for me. And I'm quite curious how it tests at 58-59 RC.
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For me, S7 as a knife steel makes perfect sense. Landes uses S1 steel for his toughest kitchen(?) knives (his usual ones are AEBL), btw, with ultra thin edges, that can go through bone and not chip. Haakonsen uses A8mod (S7 substitute, a bit less tough, but with more wear resistance and corrosion resistance, too). With the great resistance to chipping, it will slow wear, not microchip. Of course I would use it in a big chopper or in a knife to see battoning, not in a slicer. For a slicer/fighter, I would go with AEBL.
 
kuraki said:
I know you don't. I just don't understand the surprise at the AEB-L results. What qualifies something as a knife steel to you? S7 qualifies for me. And I'm quite curious how it tests at 58-59 RC.
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I guess I’m looking for the steel with the greatest wear resistance and toughness balance. Never used S7.

Hoss
 
DevinT said:
I guess I’m looking for the steel with the greatest wear resistance and toughness balance. Never used S7.

Hoss
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That’s why I’m interested in z wear and vanadis 4e. I’m hoping results for 4v will be good. I think someone made some samples.
 
I am wondering if the AEBL results where just an anomaly. Alsi what is it’s toughness at the actual hardness people use it at. 59rc seams a little low for what I seen most people run there knives at. Seams like most people are pushing it into the 61-63rc range. I also think if 15n20 was tested at the same hardness as AEB-L it would have been up there with it in toughness. What would be really interesting would be a series of tests where each sample was tuned to have the same hardness. Then hardness becomes a moot point and we can see which steels came out tougher for X hardness.

But grate job on all the work and testing you have done.
 
I didn’t do anything special for the HT on the Abel. The material is straight from Uddeholm, cut three samples, preheated the furnace, soaked for 8 minutes, plate quenched, cryo quenched, and tempered twice for one hour. It is a surprisingly tough steel.

I did some reclaimed 15n20 and it didn’t do well probably because it had stress fractures or something. Better material would have much better results.

Hoss
 
JTknives said:
I am wondering if the AEBL results where just an anomaly. Alsi what is it’s toughness at the actual hardness people use it at. 59rc seams a little low for what I seen most people run there knives at. Seams like most people are pushing it into the 61-63rc range. I also think if 15n20 was tested at the same hardness as AEB-L it would have been up there with it in toughness. What would be really interesting would be a series of tests where each sample was tuned to have the same hardness. Then hardness becomes a moot point and we can see which steels came out tougher for X hardness.

But grate job on all the work and testing you have done.
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We do three samples of every steel/condition to avoid anomalies. If you look at the chart you will see that most of the steels were tested in the 59-61 Rc range. It is difficult to get it much tighter than that. The higher the hardness the closer together the different steels are so if only one hardness can be done I would prefer it to be around 60 Rc. The best case would be a series of austenitizing-tempering combinations for a range of parameters and hardness and then a full understanding of toughness relative to hardness is known. However, the more parameters are studied the more samples are required and up to this point we just don't have the volunteers and time required to do that level of work.
 
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