Cabon steel vs Stainless steel

[me2]

Hardenable stainless steel dates back to 1915. The steel I'm specifically thinking of is AEB-L. As far as I know, it dates back to the 1920s or 1930s. There is a family of 13% chromium stainless steels such as 420J2, 420hc, AEB-L, 12C27, 13C26, 14C28N, 8Cr13MoV, etc with similar properties. The heat treatment is a bit more demanding, but to date, 12C27 is the easiest steel to sharpen to a high sharpness I've encountered.

Yes , I should be more specific. 10 to 12 % free chromium. Verhoevens book explains many of the intricacies of free chromium and how to get the amount needed in combination with the carbon available, and required temperatures.

I don't think wear resistance is terribly good at predicting edge holding either, but it depends on how one is measuring it. It's a good predictor in CATRA type tests, but less reliable in hand held applications. A certain minimum is needed, but beyond that I'm not so sure.

D2 had a lot of carbon, but it's not stainless by normal definitions. All that chromium is in there for hardenability and carbides. It certainly helps, but not like stainless. I've not been impressed with the CPM alloys. I have an S110V knife I'm trying out, but shop far I'm underwhelmed. It could be my lack of proficiency at sharpening it though. I tend to prefer a high sharpness as well, and just sharpen those types of steels more often than I feel I should, particularly when price is considered. I have some M2 at 64 to 66 HRc and it's wonderful. Longest edge holding I've tested so far.

[Mark Reich]

I don't know of a tungsten steel I don't love. M2 and M4 are amazing. All Hitachi blue steels are outstanding, and ZDP 189 is my favorite stainless.

I never would have guessed AEB-L was that old, but it is way underappreciated, and I have no idea why. By the book, it does look plain, but so does 52100, and the Skandi steels (except 8Cr13MoV). I can only guess that super clean, fine grain is more important than people give credit.

I have always been aware that 52100 can have extremely fine grain, and I pull out all the stops to obtain it. Between that, and the right cryo, I don't have another explanation for the performance of my knives. In the same hands, M2 at 64 is not a lot better. The biggest difference is my knives will not break, and M2 is not very tough, but I would love to try M2 with the way I draw my blades.  

I have a nice bar of CPM D2 that I've been wanting to try. I could probably get 4 blades out of it, and send them to Brad at Peter's for HT. I've heard great things, like it's better than regular D2 in every way. Even ease of sharpening, which CPM stuff tends not to be, but I hear a lot of people have trouble sharpening D2.

Mr. Me2, what do you think about forging CPM D2 a little? I could get way more use out of the bar if I could rough shape with distal taper.

[me2]

Holding it too hot for too long will loose the fine carbides CPM is known for, but I doubt rough forging would be a problem as long as the temperature recommendations were followed.  It's likely to be stronger at forging heat than you're used to, so be prepared to hit it hard.

[Mark Reich]

Yes, interesting. Thank you.