How To Heat treat D2 yanagi-ba

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Nico Cappelli

Joined
Apr 20, 2019
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Hello guys, i'm new in this forum.
I wanted to make a yanagiba in n690co but I confused the steel plates I own and now I realized that I used the k110 (aisi d2)
I know it is not the most suitable steel for this type of knife but I am sorry to throw it away, so I would like to proceed with the most suitable heat treatment for this knife and its use. I believe that the goal of ht, in this case, is to obtain the finest grain possible, to improve the stability of the edge. In order to get it, I would like to know what austenitization temperature you recommend and soking time. Also the tempering temperature to obtain an adequate hardness.
As equipment, I have an electric oven with programmabile PID that controls the temperature ramp, and a self-built refrigerating machine that reaches - 78° c(-109F). Sorry for my English, greetings from Italy
 
For D2

Preheat oven to 1980F, let soak for 30 min once at temp

wrap blade in 309 high temp stainless foil, put seams along the side so they don't interfere with plate quench
turn oven off

Put blade in oven, turn oven back on and set to 1880F. The oven will probably have fallen below 1880 and may take a little while to get back up to 1880
Once the oven reaches 1880F start timer. Soak for 30 minutes <--- this soak at temp is very important

Remove blade and quench between two large metal plates. Aluminum or steel is fine. Use weight or clamps to keep the plates tight to the work. Plates keep your work straight and provide a more rapid quench than air and is helpful

After about 2-3 minutes pull blade from plate, cut open foil with tin snips.

Wrap blade in towel and put into cooler filled with dry ice or liquid nitrogen. Let soak 30 minutes or until down to temp

Remove from freeze and put into pre-heated oven and temper at 425F for one hour

Pull from oven and get down to room temp, water is fine

Temper at 425F again for another hour

Measure hardness should be around HRC62



If the blade has a warp to it, you can clamp it straight for the final temper, or perhaps the thickness of a coin shim past straight and it will come out of temper straighter.

The rapid quench from plate quenching is important

you preheat the oven empty because the radiant heat from the coils can overheat parts of the blade while it gets up to temp. This is not true for all ovens, but there's a pretty good chance it will effect you.

You soak the oven empty a little hotter than temp so you're closer to nominal when you put your work in and turn it back on. The idea is to minimize time spent with the coils on full with the blade in the oven. This is to reduce over heating spots of the blade.

Your oven may or may not have accurate temperature. Some folks find they have to go over or under their target temp to get what they're looking for.

Sub zero or cryo is a continuation of the quench. Don't temper first or you'll stabilize RA
 
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Nico Cappelli said:
Thank you every body



I meticulously followed the procedure posted by nathan and I must say that a great job came. No plate quench distortion! Good hardness, measured on tang, 61 / 62hrc. Now it's time to put an edge and try if hold it well!
Click to expand...
It looks great!
 
Mo2 said:
It looks great!
Click to expand...
Thank you!
But this is nothing special, just a Simple yanagiba.
I hope don't go off topic, but I would like to ask what angle I could make the microbevel, considering this type of Steel and that the thickness at the edge is 0.2mm (0,008").
 
Nico Cappelli said:
Thank you!
But this is nothing special, just a Simple yanagiba.
I hope don't go off topic, but I would like to ask what angle I could make the microbevel, considering this type of Steel and that the thickness at the edge is 0.2mm (0,008").
Click to expand...
Unfortunately I do not know.

Maybe DeadboxHero DeadboxHero or
Nathan the Machinist Nathan the Machinist
Could help with that. I'm not a big chef knife user with that kind of excellent geometry.
 
Nico Cappelli said:
Thank you!
But this is nothing special, just a Simple yanagiba.
I hope don't go off topic, but I would like to ask what angle I could make the microbevel, considering this type of Steel and that the thickness at the edge is 0.2mm (0,008").
Click to expand...

I used to run 13DPS on thin skinners in that steel. That's about as narrow as you can push it.
 
The main bevel on your blade is probably around 8 degrees ( 7 degrees for a 1" kiriha, and 9 degrees for a .75" kiriha). The microbevel should be 5 to 10 degrees higher .... depending on the steel and usage. I would do the single microbevel (omote side) at 15 degrees and see how it cuts. If it is chippy, increase to 17-18 degrees. If it cuts OK, with no chipping, try dropping to 12-13 degrees. If you like the feel and it cuts well at 15 degrees,leave it there.

Note - Never put any microbevel on the ura below the urasuki. The only time I do this is an emergency repair after the edge gets a bit chippy and I don't have time to re-do the whole kiriha and re-flatten the ura.
 
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Mo2 said:
Unfortunately I do not know.

Maybe DeadboxHero DeadboxHero or
Nathan the Machinist Nathan the Machinist
Could help with that. I'm not a big chef knife user with that kind of excellent geometry.
Click to expand...
Nah, Nathan is the leading expert with D2.
He has generously shared a huge amount of information one can find with the search feature

I don't use that steel.
I personally would not select that steel for a Yanagi.
 
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