View Full Version : Quenching 440C


Tbonz
02-27-2005, 12:47 AM
I'm going to heat treat 440c for the first time and I would like to know should it be quenched using quench plates as I have done with 154CM . One formula states that it should be quenched on a grate or wire mesh. Any suggestions on air quenching 440c will be appreciated.
Thanks
Tim

hogcat
02-27-2005, 06:19 AM
I did a search on this forum for 440c stainless. the best idea I read was to air quench with a good strong supply of fast moving air. Like a strong fan funneled down on the blade. And having the blade longwise, so bothsides of the blade get the same amount of air. Some folks say you can use oil to quench. I have always used O1 tool steel before, and oil quenched. Have some 440c coming, but will air quench.

nate d.
02-27-2005, 06:51 AM
Hogcat,
I use 440C pretty regular in pocket and straight blades. I prefer my quench plate to anything else. Just be careful that you don't allow the blade to sit to long on one quench plate before putting the plate on top of the blade. Otherwise you can warp the hole blade. this is only an issue on .060 thick blade materials. I have a set of copper and steel quench plates and love them. you can't go wrong with quench plate that lower the termperature so much faster than useing any other means resulting in finer martensitic structure (good) with less austenite (bad).

hogcat
02-28-2005, 02:39 PM
Nate, do you leave if ya use it, the stainless tool wrap on the blade when you quench? My 440c should be here today. Will probably hog out a blade later today.

nate d.
02-28-2005, 04:52 PM
I leave the blade in the tool wrap. that brings up a bunch of good points that i didn't include.
put stainless steel foil on all stainless steel blades period. Don't bother to try and HT any other way period (i've done it and it sucks). drop a piece of tissue paper or any paper in with the blade to help and consume as much oxygen as possible.

I have to quench with the tool wrap on because i can't get it out of the foil in time to be able to get it quenched in time to get a good quench. I also leave a little bit more metal on the blade cutting edges so that i don't run into warped blades. maybe later in life i'll learn how to quickly get it out of the foil and between the chill block quickly but right now i'm not able to. I haven't had a warped cutting edge yet. now i have warped an entire blade before because i let it sit on the bottom copper plate to long with out the top copper plate on it. So now i have both copper plates ready and place them on at nearly the same time. anyway. keep asking questions and i'll try and help you as i can.

Tbonz
02-28-2005, 05:36 PM
Thanks NateD,
I'll use my quench plates. Right now I'm using steel plates but I plan on procuring some 1" thick aluminium plates as I've read that they disperse heat a bit faster.
Tim

Allen Rice
02-28-2005, 07:41 PM
Nate,

What is the thickness of your copper plates? I have some 5/16" copper plate that I'm thinking about using.

Copper being about 3.3 times as dense and having about a 1.65 heat transfer advantage over Aluminum I'm thinking it would be nearly ideal. Unfortunately it is now about 4 times as expensive.

Have you done any comparisons between using Aluminum and Copper.

Allen

mete
02-28-2005, 08:08 PM
Thermal conductivity , Al - .53, Cu - .94, Fe - .18, Ag - 1.0

RJ Martin
02-28-2005, 11:09 PM
1" thick (or thicker) aluminum is fine. If you have 3/4' or thicker copper, that would be fine too. I wouldn't go any thinner than that.