Chilling Plates

Lerch

Well-Known Member
Hi all

When plate quenching stainless steel is there any benefit to chilling the aluminum plates in a fridge before you quench the steel? I have done this some times and sometimes not, i thought maybe it would help when doing 2 or 3 blades on one set of large blocks

just wanted to know if there was a pro or con to this or if it is pointless

thanks
steve
 
I don't think it benefits or harms the quench. It may allow more quenches before the plates get too hot to handle. I have cooled off plates in a snowbank between quenches. Similar idea.
 
I have used chilled/frozen plates to accelerate the quench when HTing 3v, it does not seem to reach full hardness with a standard plate quench unless the stock is very thin. Still comes out about a half a point harder when I send them to Peter's.
 
I find it unlikely that cooling plates from, say 60-80 F (room temp) to below 32 F will
make much difference to steel at something like 1800 F, especially given that the
critical temperature you have to get the still passed is around 800-1000 F. Maybe
I'm wrong, but the difference in plate temp just doesn't seem very significant in
this scale of things.

Cooling plates in between quenches is clearly a different matter because they're
going to be warmer then.

Note that this isn't the same question as warming quenching oil because the warming
reduces the viscosity of the oil and makes it work better.
 
Ya i didnt figure in the scheme of things a 20deg plate would have much effect on a 1950deg blade so i figured it was probably a waste anyway,

just thought i would ask, i guess i was probably more worried it could have some kind of detrimental effect

thanks
steve
 
I put mine in the chest freezer for about an hour beforehand, but I have no proof that it makes it better or more effective. I started doing this because I had a couple instances where one of two/three blades didn't come out fully hardened after the quench. I seem to have better luck now that I am freezing them a little now. Why or how, I don't know. It is just working for me. If you are getting good results without doing it, I would continue with what you are doing.
 
I have thought about using a fish tank pump and running water through the plates. But I do have another set of plates that I use when the first plates get warm. Here is my setup.
100_1356.jpg
 
Well I dont have anything as elaborate as your vise, what i have been doing is chilling the plates in my freezer from when i start the oven to heat treat. Place the blades down on the plates and then typically i stand on the plates in my drive way so he south or north wind can blow a little between them. As long as the blades arent overly large ( 8" or under) i can usually hand hold the blades by the 2 minute mark.

If anyone thinks this is not enough please let me know what else i can do

thanks
steve
 
What you are doing is pretty close to what we do here. We use heavy plastic clamps instead of standing on them and our wind is generally east west - but that doesn't matter cause the shop door is closed. :)

The vice thing is really cool, but our pates are 1 ft x 2 ft, so I think I'd have to design a hydraulic damper to handle the weight. Too much tinkerin'..... :)

Your process is also the same as what we do here. The only ones that get triple temper are ones that the manufacturer specifies it (like CPM3V) or if a maker specifically asks for a third temper.

Sounds like you've got it nailed Steve.
 
Well that is one way to do it. I think that is enough pressure, but I don't to stand there for two minutes. With my vice I don't tighten it with a lot of pressure just enough for ssolid contact.
 
well my first thought was to place a 45lb bench press weight on the plate to add some weight but i figured iron on top would only add to any heat storage. in all honesty i think the weight of the plates is more than likely enough to ensure and rigidity of the foil is compressed down into the plate but i thought the added weight of my 200lb butt might help to flatten out any possible bend in some of the thinner blades i have done but straightness would only be limited to thickness of the spine so that idea was out anyway.

steve
 
The solid contact on the blade will help remove the heat from the blade faster. That is why you want some wieght on it.
 
I have no idea about the original question but I can share that there are many inexpensive post surgery pumps on the market for chilling things down.
http://www.ebay.com/itm/Aqua-Relief...d=100005&prg=1088&rk=1&rkt=4&sd=251464376325&

but only if you have your cutting done at a high class place. when my knee was done by Duke, got a nice one that plugs in the wall. when other knee was done by UNC, got a cheapy you have to pump by hand. guess that is why Duke won't take my current heath insurance. lol.
 
I got my plates from the local scrap yard , what I bought was a piece of bar stock 4' x 3.5'' x 3.5'',cut it in 1/2 and now have 2 plates each 2' x3.5'' x 3.5''.They act as one heck of a heat sink.
 
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