D2 Heat Treat Problems

jtdesigns

jtdesigns

Joined
May 2, 2011
Messages
181
I have heat treated several D2 blades before. My process is: blade goes in oven, ramps to 1250 and holds for 5 minutes then up to 1850 and hold for 30 minutes. Remove, plate quench between two frozen 1" aluminum plates. File skates across blade no problem (as before) but this time.....blade warped. I have never dealt with this before and cant figure what happened. Maybe should have clamped blade between plates. I will try that unless anyone can tell me a better way. Anyway, my other question: Should I try and anneal this blade before re heat treating or just put it in for another cycle and straighten as it comes out?

Jeff
 
It is difficult to anneal D-2. Try this,put it through he hardening process again then straighten it immediately after the quench. You will have about 3 minutes that you can easily bend the steel without breaking it.
Quench it for only about a minute,it will be cool enough to handle by then.
 
D2 comes in a lot of flavors. Like high speed steel, many of them experience extreme grain growth upon a second austenization at those temperatures without normalizing first. But some don't.
 
My own personal experience here also goes contrary to the literature. :thumbup:

I'm not totally sure a complete anneal is necessary or even beneficial (it negates other things that are good that can happen in this situation) but then you're getting into idiocracies of the alloy that varies from manufacturer to manufacturer and even lot to lot where it would be ill advised to give generalized advice.

edit:
In this particular situation, I might scrap the work piece (I've done it many times) rather than fool with a rework, or if it isn't critical work I might re-austenitize at 1800 for 15 min rather than full time and temp because the carbon is already in solution. This approach minimizes the risk one takes when you may have a high chrome, low vanadium variant.
 
Did I miss something here? If it is warp he is having problems with why do another high heat? Why not just clamp and whim to straighten during the tempering process. I do my heat treat the same way and I had warp issues when the blades came out of the quench plates. I just straightened while tempering. Seemed to work just fine.
 
You're not missing anything at all, that is the first thing to try.
 
He asked if he should anneal it or re treat it and straighten it when it comes out of hardening,at least that's the way I understood it and so I told him to re treat it and straighten it as soon as it gets cool enough to handle. I don't know how bad it's warped or how long it is,I just know that D-2 is very difficult to straighten after its been hardened.
 
I did not understand why my blades warped between quench plates but I can attest to what Calvin said, that D2 was more difficult to get straight.
 
I've had some slight warpage using plates. I don't know what's caused it, but I was speculating that putting the blade down flat on one plate cools one side unevenly while you are working to get te other plate on and in form contact.
 
Put it through another cycle, quenched it between frozen plates, applied clamps and let it cool completely. Came out straight and hard:D.....Seriously though, don't know if I caused significant grain growth. Don't really want to break it and see but may sharpen it and put it through journeyman smith test (minus 90 degree bend).
 
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