View Full Version : will this work for heat treating 440c?
08-01-2010, 04:43 PM
440C Stainless -
Preheat thoroughly at 1400/1500ºF and hold for 30 minutes.
Raise heat to 1950º F and hold for one hour.
Air quench at room temperature. Subzero freeze at 100º below 0.
Tempering: Temper at 400ºF for one hour, two times
without the sub zero or does someone have a better recipe
08-01-2010, 05:12 PM
I used the search and found the info
08-01-2010, 05:15 PM
I go to 1250 hold 15 min,1650 hold 15 min,1940 hold for 40 min,plate quench,into cryo,temper 375 x 2 hours twice.
cryo is not necessary but 440-c really likes it.
08-01-2010, 05:16 PM
Thanks Stan how much is involved in setting up for cryo?
08-01-2010, 05:41 PM
I bought a dewar and use liquid nitrogen but you can do it with dry ice and alcohol.
Get a cooler big enough for your knife to fit in.get a couple of pounds of dry ice,crush it up and mix in alcohol to make a slurry.
leave the knife in till the dry ice evaporates.
08-01-2010, 06:15 PM
I may have to try the dryice method well my first blade ever heat treated by me is tempering at this time
08-01-2010, 06:16 PM
when you said 375 twice , do iI let it get to room temp after the first 2 hrs then do it again?
08-01-2010, 06:17 PM
What type of alcohol rubbing, denatured?
08-01-2010, 06:19 PM
Yes let it come to room temp between tempers,cheap rubbing,not good drinking.
08-01-2010, 06:53 PM
Definetly gonna have to buy some of that high temp foil its a good thing I left a lot of metal on it.
08-02-2010, 03:58 PM
You should temper once before cryo, then after.
I think 1950 is a little high, and would promote grain growth, whitch in turn leads to a brittle blade. Latrobe steel says 1850-1900. I been using 1880 for 30 minutes.
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