Plate quench 3/32 O1

J

jawilder

Joined
Jun 27, 2006
Messages
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let me start by saying that I know that O1 needs a medium speed oil.

with that being said, I am looking for a better way to keep my kitchen blades dead straight during the quench and recall that Butch had experimented with quenching 3/32 and under between Al plates.

I tried this last night on a 5" santoku blade but got mixed results.

I releaved stress at 1200 for 20 minutes, ramped to 1480 then quenched between 1" plates.

there was a lot of scale and only certain areas got hard. I was able to test with tester files. some areas were 60 plus and some were 55 plus. its there any way to get more consistent hardness throughout using Al?

maybe stainless foil to keep scale down?
 
You may need to quench then grind, if thats not what you did. Contact with the plate provides faster quenching, and bevels wont make good contact.
 
You know me2, that is exactly how I did it. I used the plates to straighten the blanks and they hardened all the way.
Daniel Combs
DanCo
 
I grind anything under 3/32 after HT. this was profiled only. I wonder if there was to much scale from 20 min stress relief and another 20 minute soak.
 
jawilder said:
I grind anything under 3/32 after HT. this was profiled only. I wonder if there was to much scale from 20 min stress relief and another 20 minute soak.
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I think a good tight foil wrap should prevent that. It certainly seems worth a try.
 
Maybe this is thinking outside the box, maybe it's just plain dumb, but would it be possible to clamp the blade between the plates, then dunk blade, plates, clamps and all in the oil?

Or maybe clamp the blade between steel plates before HT and leave them between the steel plates throughout HT and quench?
 
The advantage of plate quenching is it comes out straight, but even thin kitchen knife O1 or another Oil hardening steel doesnt cool fast enough to harden fully, if it was ground and doesnt contact to plates. I remember that Butch quenched the profiles, not ground.

I have hardened a thin santoku ground, first dunking to oil only a second then between the plates and pressed really hard between vise jaws, It came out straight and hard like glass..
 
You said you ramped up to 1480F from 1200F.

1. Did you allow your kiln to equalize at 1200F before putting the blade in?
2. What was your ramping rate?
 
Rick Marchand said:
You said you ramped up to 1480F from 1200F.

1. Did you allow your kiln to equalize at 1200F before putting the blade in?
2. What was your ramping rate?
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I have it set up to take 30 minutes to get to 1200, and hold for about 15 minutes before I put blade in. Then soak at 1200 for 20 minutes. Take 10 minutes to ramp to 1480, then soak for 20 minutes before quench.
 
I'm sure Butch will chime in, but yes, everybody's recollection is right. The blanks were full thickness at quench time. All beveling happened after HT. I believe he had them foil wrapped as well.

-d
 
I really think foil wrapped might be the key as the scale would slow down the colling rate. There are spots that are obviously harder (shinier) than the softer darker spots. I think the darker spots were where scale was sandwhiched between the blade and Al. I'll try to take a picture of it tonight before I try again.
 
anti scale coating from brownells works great and is easier and cheaper than foil. When I use it there is no scale or decarb after ht.
 
That is almost a full rate. I'm willing to bet that sections of your blade got to 1600F+ ask the elements kicked on to ramp up. Do you sheild them at all. If not that would contribute to excessive scaling.
 
I know this does't answer the original question... but why not use A2 instead for thin stuff? air-quenched (can use plates), and noted for its dimensional stability during heat-treat. It's like O1 on steroids. You get all the carbon tool steel love with a simpler, safer heat-treat schedule (and a bit more wear & stain resistance)
 
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