heat treating multiple blades -- soak times

L

llecardu

Joined
May 31, 2008
Messages
55
how do you go about treating multiple air hardening blades? doing them one at a time, i understand you will get grain growth due to some of the blades over soaking. should i just get quench plates for every blade?
 
You don't have to worry about the grain growth as long as the oven temp stays constant. Wrap each blade in it's own packet and pull one at a time to plate quench. Between the quenches, put a frozen gallon milk jug of water in the plates to cool them back down. You can easily do a dozen blades this way, if your oven will hold them.
 
Thanks, I was wondering exactly the same thing.

Stacy, when you say oven temp stays constant, won't opening the door cause a fluctuation?
 
I don't worry about that much. It may drop down some, but depending on the ovens thermal mass and the size of the blades they should not drop that much. Mostly the air in the oven is getting replaced with cooler air, which should come right back up unless you have a slow oven or leave the door open for more than a few seconds. Plus once the steel is austensetic it doesn't start back the other way fast. I figure it as just soak time. Look at the chart for something like D2. Even 1095 has quite a bit of time from 1475 to 1350. Soak time does not cause grain growth. Over temp does.
 
What I meant was as far as it is in a regulated oven. Once soaked at, say 1850°F, for thirty minutes, a little drop won't matter as you pull the packets. The oven will probably recover before you pull the next blade, anyway.

Jim covered it pretty well.
 
You must log in or register to reply here.
Back
Top