quenching integrals

J

Justin King

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Nov 8, 2009
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I'm working on my first integral piece and not sure if I should quench the blade only, or harden the whole thing. The steel is W-1, I will be using a digital oven and quenching in fast oil. I am not doing any clay coating or differential hardening. Any tips or advice?
 
I'd do a couple subcritical stress relief cycles first to minimize risk of warping and I'd do an interrupted quench (pulled after about 10 seconds) to reduce risk of cracking and allow straightening. I would have a plan for straightening the blade immediately after the quench and practice with a dry run first.

Integrals are tricky to straighten because they don't lay flat, so you want to be sure you have your head wrapped around what the geometry is supposed to look like before you're in the heat of the moment.

edit: "in the heat of the moment" Ha, I crack myself up...
 
Nathan the Machinist said:
I'd do a couple subcritical stress relief cycles first to minimize risk of warping and I'd do an interrupted quench (pulled after about 10 seconds) to reduce risk of cracking and allow straightening. I would have a plan for straightening the blade immediately after the quench and practice with a dry run first.

Integrals are tricky to straighten because they don't lay flat, so you want to be sure you have your head wrapped around what the geometry is supposed to look like before you're in the heat of the moment.

edit: "in the heat of the moment" Ha, I crack myself up...
Click to expand...

Thanks for the reply, although I'm not sure if you referring to a full quench, or blade only?

I hear you about the straightening part, this piece is forged so I've already got a taste of that part.
 
I really appreciate the replies. I may be over-thinking this, but it seems like having the handle portion still at heat while trying to straighten the blade right out of the quench would complicate things a bit. My first thought was to do a full quench, straighten as best I can right out of the quench, then fixture during tempering if necessary, and do some additional torch draws on the handle area.
 
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I'm curious what your blade geometry (edge thickness, bolster thickness, spine, etc.) is going into the ht.

With the blade being W1, even if you have the entire thing soaked at temp going into the quench, the bolster area most likely won't get hard (that's a lot of steel to cool off in such a hurry).

If you were using O1, 52100, etc. then getting the whole damn thing screaming hard would be cake. But W1, not so much.
 
The blade is about .200 at the spine and .045 at the edge, full flat ground. The bolster area is about 1/2" thick, there is a reduced section in the grip area ( about .200 thick) for scales, and the pommel is about 5/8" thick, give or take. I'm not worried about the bolster and pommel areas being fully hard, in fact if I do harden the whole thing I will draw these parts with a torch just to make them easier to finish out, if nothing else. But it seems like straightening the blade out of the quench with these parts still hot would be tricky, at best.
 
If you can live without the precision of a real oven, or if you have access to a pyrometer, a gas forge gives you a lot of options re: heating only part of a piece, in this case the blade.
Definitely a tradeoff, though.
I frequently rearrange the fire brick on the ends of my propane forge so that I can stick just one part of a work piece into the heat.
 
What I'm saying is that even if you quench the whole thing, you're VERY likely to get a differentially hardened blade. In the OP you said you didn't want to differentially harden it.

IMHO, if you do get any blade warp, it would be a lot easier to straighten it during temper rather than while cooling down from the quench.
 
NickWheeler said:
What I'm saying is that even if you quench the whole thing, you're VERY likely to get a differentially hardened blade. In the OP you said you didn't want to differentially harden it.

IMHO, if you do get any blade warp, it would be a lot easier to straighten it during temper rather than while cooling down from the quench.
Click to expand...

I see what youre saying. I'm not intending a differential quench, but oil quenched W-1 will be what it will be. I'm not nearly brave enough to water quench this thing.
 
I agree with Nick. I've done many integrals in W1 and W2, using a forge for HT. Even with you using an oven, the thick parts probably won't harden. You can give the parts you may want to stay full soft some thick clay, like the thinner part of the tang. Even with the blade full hot and quenching without hamon clay, if you thermal cycled a couple times after forging, and once after grinding, I'd rely on the blade to not warp much, and correct if necessary with a shimmed temper. It can be done pretty well on an integral blade.

I've quenched plenty integrals with the bolster hot enough, you can see a plume of pearlite running into the martensite up toward the spine from the bolster.
 
Thanks for the replies, guys. I was working on this piece yesterday and figured out that I fullered too far back into the ricasso when I pinched the blade out and lost an important dimension, so now I have a test piece for heat treating:(
 
NickWheeler said:
What I'm saying is that even if you quench the whole thing, you're VERY likely to get a differentially hardened blade. In the OP you said you didn't want to differentially harden it.

IMHO, if you do get any blade warp, it would be a lot easier to straighten it during temper rather than while cooling down from the quench.
Click to expand...

Nick nailed it. The mass of hot steel in the bolster will not cool fast enough to fully harden. Just make sure you harden the entire edge. The hot bolster may even limit the hardness of the last piece of the edge.
 
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