Stainless san mai, core steel testing.......
Im very happy with 01 as an uber fine grained staple core steel. It takes a fantastic edge and gives reasonable edge retention whilst being very nice to sharpen. Exactly as you would want from a good carbon steel.
I would like to flirt with some other options, not super wear resistant, but something a little less fine grained, toothier quality and greater wear resistance, whilst not being overly hard to sharpen. I have read lots of bad and good things about D2, many contradictory to each other. But from the offset and having read some excellent papers with heat treat tests on the steels grain structure and ultimate toughness I would say there is a lot in a heat treatment. So with my own testing Im aiming the the finest grain possible whilst being as hard as possible without being brittle.
I tried a few different austenitizing temperatures which were quite close, these produced the finest grain to the naked eye.
I went with the later lower temperature for the rest of the samples. To me this grain is surprisingly small and even to what I have heard of D2. It is not as fine as 01 but finer than something like blue paper steel, which has a slightly courser structure to the naked eye.
The pieces were 65hrc after a plate quench followed by cryo. They were also very very hard to break, Already some tough stuff over this thickness.
3 samples I then used to bracket my temper temperature. Each had 3 temper cycles at one hour. This is important to this steel it has been proven. I also gave them all a second cryo for good measure.
Each piece I then ground and sharpened, a pretty crude grind but with a fairly low final angle about 15 degrees per side. With each I cut notches in some mild steel until they would no longer perform the task or until dulled significantly.
The one I have settled on as my ideal temper temperature managed this complete row without chipping in the slightest, just a little dulling which came out easily on a chosera 1000 grit stone.
This was the two with a lower temper temperature.
This is the piece with a slightly higher temper temperature and the HT I will settle on for further testing. Final hardness 61/62hrc
Next to make a knife out of it to get an idea how I like it on a much thinner edge and get a feel for edge retention vs sharpenability.
Im hoping to make same nice hard wearing slicey 210 line knives in this steel with stainless cladding. I am also waiting for some cpm 3v to arrive, which I believe I will like for different reasons.
Ill update as I manage to get a san mai knife together with out melting the stuff
Great testing photos. Thanks for sharing. I have worked with a few diffrent D2 steels and the D2 thats made of powder steel.. Is some amazing stuff! If ya really want to make it more wear resistant. Cryo it!! Takes it from tough to CRAZY tough!!
Yep, these pieces were cryo'd twice. I did not try a piece without cryo, except for a hardness test prior to cryo and it brought it up 1-2hrc. Looking forward to trying it in context of a chef knife. Cheers Folks.
I missed that in your post. Sorry. Yep I have yet to try it as a kitchen knife. Mainly using it for camp knives, and or smaller carving knives. One you get the stuff sharp it stays that way a very very long time!!
Have fun and thanks again for sharing
Good to hear mate, thanks. Looking forward to trying the 3V too. I can only get it in 12mm so a fair bit of forging out if it works out in san mai.
That's a really cool way of testing Will!
It is always interesting to follow craftsmen trying out/testing new things which is a testament of their mastery of the basic skills required and is free to be creative and find new things, methods/ techniques to reach a new height of which is never ending.
Been following your tweaks as to handles, profiles, geometry, materials heat treats etc as it is informative and broadens my knowledge as to a well made knife in terms of form and function and what you guys go thru to make one. WIPS is always a joy to follow. Videoes.. can't ask for more.
Comparing your first few knives and the the recent few knives to your latest.... it has become a never ending quest for me too and I can't keep up with you.
Of all, my favourites are still the "USA Passaround" ( http://www.kitchenknifeforums.com/sh...-S-Pass-around) and the Twin Petty (( 68,000 layersdidn't manage to snag the Feather damascus) as it constantly reminds me of your journey... and I did't make a mistake is spotting a budding craftsman then.
Have fun.. always
Thanks David, your, confidence in my work, support and advise has and is very helpful along the way
D2 core san mai...
Stress relieving before doing a full anneal on two stainless damascus clad D2 core blades.