Working with D2

Nate, I'm not sure I could offer a better suggestion. San Mai isn't my thing, so maybe someone else can chime in, here.
 
Sidebar: Got the grinder wheel. works quite nicely.
I0YGJCk.jpg
 
So far, it seems to have worked.
W44oqFD.jpg

The outer jacket of tool steel sits somewhere between 45 & 50 HRC, and the D2 interior skates a 65 HRC file.

A quick etch shows a marvelous contrast:
66riZwo.jpg

kgSKv0u.jpg


Also, the grinder worked like a champ.... until it hit the hardened D2. The O1 is kind of thin on one side. Dear god... that stuff is OFF the charts hard. But it is a proof of concept.
 
Nate, the point I'm trying to make is that this is hardly something to shoot for. The structures of both the jacket and the core are likely catastrophes. 45-50rc is NOT 'soft'. Also, what state is that steel in? How large is the grain? Is it offering you any advantage at all? What is the D2 core like? Other than being hard, you have no idea what else is going on with it. This is why everyone was talking about controlled heat to anneal, etc. If your goal is just 'hard' and 'soft', then I'll back out of this and leave you to it, but I've always thought the idea was to make a better tool. As you've got some much invested in this, I have to assume you feel the same. :)




nateman_doo said:
But it is a proof of concept.
Click to expand...
 
I guess I should have said I am pleased that forge welding D2 and O1 can be done. I read that it could not be done, but that was after I did it. I doubt I will do anything with this billet until I can anneal it (IF i can anneal it). Just was impressed with a successful forge weld. Usually once I sent my mind on something I keep at it until i do it, or utter failure. I was ready to write off the project, but figure I will give it one more go as i have one more piece of the stuff left.

I am not buying a furnace just yet, so i want to experiment with adding more mass to the forge. Once I am done forging a billet with D2/O1, start adding steel to the forge and get that up to temp. Heat up a 2x4 1/4" walled tubular steel and stuff it all in there. I am hoping the mass of all this still will slow the rate enough to make the D2 workable. Also I found that the core D2 needs to be thinner then the O1 cladding. The O1 tends to fold over both ends when drawing out the steel. plus it moves less.

Still impressed with the grinding setup, and still in awe with how incredible D2 is. Just a hint of it showing up below the O1 was enough to make the grinding cup struggle to the point my machine went into thermal overload. But what you are saying is correct. Making a better tool. A heat treat oven will eventually get purchased, but until then I am just experimenting.
 
Very cool, Nate, but my point isn't about the methods you're using, it's about the combinations you're choosing. They're bad. It won't matter if you have an atmospherically controlled, state of the art heat treatment facility - the steel combinations you're using are NOT complementary. Processing one properly will wreck the other, and vice versa. The reason you may not have seen this done before is because it shouldn't be. If you want to use D2 or another alloy for your core, you need to find something that uses comparable processing for the jacketing. That's why most Damascus is made with the materials it's made with - O1/L6, 1084/15N20, etc. the paired steels have VERY similar process requirements. OR, in the case of San Mai, they may use stuff that won't harden at all (wrought iron, for example) for the cladding. Good luck!
 
MG is correct, if you want to use D2 as the core, use 403, 410, 416, or 420 for the cladding.

Hoss
 
How where you planing on heat treating this steel?
 
nateman_doo said:
why those specifically?
Click to expand...

I'm deducing that they're more compatible because they can withstand the temperatures and soak required to heat treat D2 properly. O1 is not and will see a lot of grain enlargement at those temps and times. Grain enlargement equals dimensional shift. Dimensional shift in one layer of laminate steel while the other remains stable is bad for the integrity of the blade.
 
kuraki said:
I'm deducing that they're more compatible because they can withstand the temperatures and soak required to heat treat D2 properly. O1 is not and will see a lot of grain enlargement at those temps and times. Grain enlargement equals dimensional shift. Dimensional shift in one layer of laminate steel while the other remains stable is bad for the integrity of the blade.
Click to expand...

Interesting. I guess I am hinging everything on how amazing D2 is to hold up the blade. Only way to know is to finish it. I have 1 more billet left over that I plan to forge weld. Not like I have anything else I can do with it, so might as well finish it. 3rd time should be the charm. If it's successful at least I can check the block and say I made a knife from D2 and never look back.
 
I ruined my last D2 billet. Simply walked away from the forge for a few minutes and the D2 got white hot and sort of crumbled. I thought the O1 would have got destroyed long before, but not the case. So that will probably be the last attempt at it (before I get an oven)

As for the other idea of additional mass in the forge to slow down the cooling rate, that is in the works. I have a section 24" length of tubular steel 2x4 (quarter inch thick walled) in there, with a 1x3 section inside it about the same length. The billet is in the tubular steel on top of the 1x3. Hopefully the heat rising from the 1x3 will keep the D2 hot for a while.

Got nothing to lose at this point.
 
It's weird to me that your repeated problem is overheating but you think slow cooling it is going to somehow fix it.
 
The difference from that small a thermal mass will only slow the cooling rate a bit. You would be better to pull the billet and place in vermiculite or ashes ... which I don't recommend as a good technique, either.

I'm with Matthew here, and think you are chasing unicorns, when good horses are already in the barn.
 
You must log in or register to reply here.
Back
Top