Toughness of S35VN and ELMAX

Lapedog said:
This graph (if I am reading it right) seems to show S30v being tougher than S35vn while also being at a higher hrc. Is that correct?

Also I have heard that lower hrc = higher toughness isn't necessarily true, and sometimes a heat treat that will make a steel hogher hrc AND higher toughness.
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Yes, that test shows S30V being tougher than S35VN, even at higher Rc.

Heat treats are complicated and there are peaks and double peaks in various qualities. Toughness is resistance to chips and breaking. Strength is the resistance to bending or rolling. Strength is strongly correlated to hardness. Sometimes, you have to lose toughness to gain strength, or vice versa. But some steels and methods of steel processing can improve both.
 
The reason I ask is becaise according to Crucible S35vn should be tougher than S30v. (Am I wrong on that?) I thought S35vn's advantages were supposed to be improved toughness and sharpenability with "negligable" decrease in wear resistance?
 
Lapedog said:
The reason I ask is becaise according to Crucible S35vn should be tougher than S30v. (Am I wrong on that?) I thought S35vn's advantages were supposed to be improved toughness and sharpenability with "negligable" decrease in wear resistance?
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Your right: Crucible says that S35VN is tougher than S30V.

"CPM S35VN was designed to offer a 15-20% improvement in toughness over CPM S30V without any loss of wear resistance or corrosion resistance. It is also easier to machine and polish than CPM S30V."
http://www.crucible.com/PDFs/Knifemaker REV June 2010.pdf
 
Lapedog said:
I don't know who to believe anymore!


YeeeeAaaaaarrrghhhh! ( scream of agony )
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I feel your pain.

The bucorp test is pretty good because it tested these steels in a consistent way. Also, it seems to be pretty well recognized by people who know steel the best that Elmax is the toughest of the powdered stainless steels. I believe, from a previous thread, that Alpha Knife Supply had a role in those bucorp toughness tests and concurs with them.
 
3v has damn good corrosion resistance and edge holding. I've had 3v from winkler and big chris. I'd say 3v edge retention is on par or a little better than s30v from my use.

That said, 3v isn't common in folders and may not be an option for the OP's choices.
 
Id be shocked if any of these use v notch toughness tests. They're all most likely un-notched, or maybe c notch. Pm steels are rarely tougher than ingot steels unless the alloying is similar, like 154cm and cpm 154.
 
Apparently 154cm is supposed to be quite tough for an ingot stainless steel. In ingot steels having too much carbides causes these carbides to clump together creating inclusions in the blade steel that are easily chipped or fractured. Also more carbides meant more inclusions. It is not that simple though as apparently some carbide formers like Vanadium and Niobium cause the grain structure of steel to be refined. There are even steels that include just a very small amount of these elements to refine grain structure, but not enough to significantly form carbides that contribute to edge retention.

Apparently until the advent of powder steel processes this is why high carbide steels could not be made very tough.

I found this video very interesting.
 
I always like these threads because of all the metallurgical science and steel experience that you read through. All I can say is I have knives made with both steels and both are great steels, definitely a cut above (no pun intended :D) average steels.
 
There seems to be some confusion on terminology. I've noticed it in a few recent threads. Grain structure and carbide structure are not the same. Steel can have fine grain and coarse carbides or vice versa. Grain structure refers to grain size and uniformity. Carbide structure refers to carbide size, type, and distribution.

On average, CPM steels aren't necessarily tougher than their ingot counterparts, ie same alloy. However, they are more consistent. A set of tests on a CPM steel might vary 20-30 ft lbs, while the ingot version might vary 50-60.
 
I have seen the little Crucible graphs that indicate that CPM154 is tougher than S30 or 35 but less abrasion resistant. IIRC, S35VN was developed to solve some chipping issues with S30V. Elmax supposedly acts like a completelydifferent steel when left above 60Rc and over the last couple of years, it seems like folks are thinking that there is no reason to leave it any softer than that
 
me2 said:
Id be shocked if any of these use v notch toughness tests. They're all most likely un-notched, or maybe c notch. Pm steels are rarely tougher than ingot steels unless the alloying is similar, like 154cm and cpm 154.
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i don't think anyone uses the un-notched test because If they did, you would see graphs with L6 going off the upper end of the scale. ;)
 
True enough. V notch would be the opposite, with a ceiling around 15. Except maybe L6 and the S series steels.
 
You might want to think about AEB L for a tough stainless. When done right(good HT and blade geometry), it is tough, easy to sharpen, stainless, good edge stability, and holds a great edge!! You would be surprised after using a knife with AEB L done right. Very fine grain, and when HT'd properly has just as good if not better microstructure than a lot of PM steels.
Elmax is good, like someone said above, it acts very differently when above 60HRC, when just below 60, it is quite tough.
 
Thanks for sharing whatever info you all have. Thank you jbmonkey for reminding the others I was just looking at S35VN and ELMAX. There seems to be differing opinions. On another forum, Mike Stewart, who has worked with both steels, has stated that S35VN is tougher. However, seems like more people on this forum lean towards ELMAX as being tougher.

I wish that BladeOps made a more definitive comparison on toughness between the two. The link that DeadboxHero mentioned said that S35VN had the Charpy V-Notch Test highest score out of all the other steels tested, but did not directly mention ELMAX in that list. The piece also said S35VN was superior to other steels in the Charpy C-Notch Test, but did not mention if this also included ELMAX. Yet later in that same piece talks about ELMAX, but more on a comparison of how it has superior edge dependability at higher HRC and more corrosion resistance, while maintaining its toughness.

Thanks Twindog for that graph, which shows ELMAX as tougher. Did not know the other steels listed included S35VN under a different code.

Just confused as ever. Been enjoying what everyone has shared and have been mulling over the info.
 
What you have may seem like a lot of contradicting information. What that likely means is they are essentially the same and the reports are just scattering around similar values. To tell a difference, you'll likely have to pick specific manufacturers and models to check against each other. Then understand that changing models or even testing 2 more of the same model could change the winner.
 
Hey me2, I was sort of thinking the same thing that they are essentially very similar. Being rather inexperienced, doubt that I would be able to tell a difference. Just was curious to know more without having to purchase more knives than I already have. Sold most of my other knives, only to have another wave of desire for new knives. Now curious about obtaining knives in each of these "super steels".
 
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