Working with D2

nateman_doo

nateman_doo

Joined
Sep 16, 2015
Messages
157
D2 is some other worldly stuff. Seems like its cracking on the edges. Even trying to leave the billet to cool off in the forge.

Got a good forge weld:
NRQPO6j.jpg


But i can't figure out why its still cracking:
3C4AFiX.jpg


It requires me to dig into the billet to remove the cracks:
3b215cV.jpg




On a side note, I am convinced this is going to work to grind billets flat:
tmJjEld.jpg

Not as much with the diamond wheel, but a cup style grinder.
 
D2 is VERY picky especaly with forging. You have to remember as it's cooling its hardening and leaving it in the forge to cool down is still WAY to fast to prevent it from hardening. When I anneal D2 it takes a long time in the heat treat oven. I heat to 1600° and hold for 2hrs then cool to 1000° at a rate of 20° per hr. I have tried 40° per hr and it also seams to work but 20 seams to be best. Crucible says 25° MAX per hr cooling. Dropping 600° @ 20°/hr is 30hrs plus the 2hr soak and then the cooling from 1000° which I do by just turning the oven off. When all said and done it's a 2 day process but makes good steel.

But all that said, those cracks look like thy happened from forging ether to hot or to cold. Like CPM3v if it feels at all easy to forge it's to late and you are in the red short range and the steel is coming apart.
 
Can you go into more detail?
i was forging it around the 2K mark. did forge easily enough with my press.

Also I dont have an oven, the forge is all I have. Perhaps if I add more steel to the forge, like heat up 2 huge masses of steel and put the billet in between, they will retain the heat longer?

or should I tap out with the D2 and move to A2? I dont want to quit yet. If I can successfully forge the billet, and CNC it to shape... I could pay someone with an oven to heat treat it.
 
In my opinion, some steels just aren't meant to be forged. I get you wanting to forge. Just seems like something is "lost" when trying to. Steels like D2, and ESPECIALLY 3v! I believe that forging either of these steels ends with a worse product. Even if I did forge, I would still perform stock removal for these steels. I use CPM3V almost exclusively for my knives, and the steel is so good when finished, I would fear goofing that up.
 
I am experimenting with it, because I wanted to make D2 san mai. I have 1095/1084/15N20 billet sandwiching a peice of D2. I didnt forge it, just welded it as a billet.

Before wasting the damascus billets, i wanted to experiment with O1/D2 billet. I HATE quitting, so if I can get the O1/D2 billet to work, then I will green light the damascus D2 billet.

Worst case I will break apart the welded billet and just use an O1 core with damascus jacket. So help me out with this D2 stuff? the knife will eventually be stock removal on the CNC, and cut with carbide tooling, but I still need to get a successful weld without cracks.
 
Not to derail far, but how do you like facing materials with that cup style grinder? I'm thinking of moving away from flycutters for facing my own work.
 
WillardCorspe said:
Not to derail far, but how do you like facing materials with that cup style grinder? I'm thinking of moving away from flycutters for facing my own work.
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the diamond cutter seems ineffective for the type of material removal I desire. I just ordered a cup style grinder from McMaster. Part number 4354A31 for around $20.00. Fits on my cannibalized arbor.
4473a1c1-a05c-digitall_635609016220000000.png
 
Gotcha!;) Advice given already sounds right to me. Sounds like it's cooling too quickly. I would try the 20 degrees an hour process. Should end up with a good billet to work with.
 
You're forging too hot. Red short occurs when the grain boundries melt and the steel crumbles. 2150f is the correct forging temperature. You are probably over 2250f.

Hoss
 
kind of hard to cool a forge 20° an hour. If taking it from 2K, down to 1K, thats 50 hours.

Tell me about these red shorts, never heard that even mentioned anywhere before. Sounds like an electrical problem :)

Either way, D2 sounds like its impossible to work properly without an oven to go right into after forging. That is going to be one hell of an electric bill. An oven is one of the things I would like to purchase next.
 
O1 can also have red short issues. It's not impossible to forge D2 there is forging info on most D2 heat treat data pages. Forge welding is obove and beyond that. I have forge welded it to other steels but my most exciting day was when I welded it to 316 stainless. I never made a blade out of it but if I attempt it again I will use the oven to heat it to proper temp.
 
nateman_doo said:
kind of hard to cool a forge 20° an hour. If taking it from 2K, down to 1K, thats 50 hours.

Tell me about these red shorts, never heard that even mentioned anywhere before. Sounds like an electrical problem :)

Either way, D2 sounds like its impossible to work properly without an oven to go right into after forging. That is going to be one hell of an electric bill. An oven is one of the things I would like to purchase next.
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A well insulated oven/kiln/furnace isn't as much of an electric hog as you'd think after it's reached the called temperature. Cooling down over X hours even less so.
 
You don't cool it from 2k deg you cool it from 1600°
 
I am going to try one last thing before I tap out. adding more mass. Eithe by way of larger chunks of steel and sandwich.... or perhaps heat up a tray of sand. More mass will retain the heat longer. I dont have the money for an oven, and the D2 is to thick for any stock removal usefulness. Will keep you guys updated.
 
This is the second time in the recent past that I've seen similar combinations of steel being used for a San Mai construction, and I simply don't understand it. The heat treatments for these alloys aren't even close, and there's no possible compromise that I can see that will create a useful advantage. Am I missing something? What is the thought process behind this?
 
Matthew Gregory said:
This is the second time in the recent past that I've seen similar combinations of steel being used for a San Mai construction, and I simply don't understand it. The heat treatments for these alloys aren't even close, and there's no possible compromise that I can see that will create a useful advantage. Am I missing something? What is the thought process behind this?
Click to expand...
Matthew Gregory Matthew Gregory That is the point I was looking for. So I can just take a blade out of the forge to air cool it, while not hardening the external O1 layers. Gives me default differential heat treatment.

I have some A2 that I will try with an O1 wrap as well if I can't get D2 to work. But in any case I have some 2x4 1/4 walled tubular steel that I am going to FILL with steel and toss it in the forge to get heated to add mass to the forge to try and slow the cooling of the D2.
 
I think I see what you're shooting for, but there's a lot more to it than that. The cladding will not be in much condition to offer you what I think you're looking for, and your core will certainly not be in the best of conditions, either. A standard temp used for austenitizing D2 for hardening is 1850°F with a 30 minute soak... what do you think the grain structure of your cladding will look like at this temp and time, for example? A2 won't be much better.

There are lots of reasons strict temperature control is important with alloys like this, and although I think I get what you're aiming for, I bet you'll find there are better ways of achieving similar, or even better, results.
 
not really looking for anything in the cladding other then something a step up from low carbon steel. Want to see what it looks like etched also.

which steels do you think would be better for this? I got some 4140 even to try as cladding for A2.
 
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