oil quenching 440c

kile

kile

Joined
Mar 19, 1999
Messages
620
I thought I would try something new today, so instead of waiting for the rest of the batch to be done so I could send them to be heat treated, I tried to heat treat 440c by quenching it in oil, the way that was discussed earlier on this form. I brought it up to non-magnetic, and then heated for about another 20 seconds, then I quenched in veggie oil that was around 160 degrees farenheit. I checked it with a file, and a file still cuts into the area that was supposed to be hardened. I ground off all the scale, and it is noticebly harder to grind than before, so i etched it, and i can see a difference in color between the area that was supposed to be hard, and the part that should have been left soft. I know Ed Fowler talked about triple quenching 440c, and I know that when it is air quenched, that it needs a soak time of about 30 minutes? Ed also said that the triple quench takes the place of the long soak time. Does this mean that if I heat it up and quench it again it will be harder next time? Also to do the triple quench do i need to wait 24 hours, why, what does this do. I am kind of confused right now, so any help would be appreciated.
thanks,
Kyle Fuglesten
 
I have triple quenched 440C it worked good and then
triple tempered at 375 it holds a edge good it's my
EDC used all the time. The quench color temp was
ornage about 1800 deg. Gib
 
Do the three quenches, like Ed said. The edge does get harder each time. It makes a very good blade.;)
 
You gentlemen have been listening, thank you for your participation.
The 24 hour wait and sitting in the home freezer between quenches promotes toughness in 52100. I have not found it necessary in 5160. I haven't worked with 5160 for years with my present forging practices thing may have changed.

I believe that probably 90% of what is going to happen happens in the first few hours after the quench. The remaining 10% (% are wild guesses) is very rewarding when everything else was done right. Same way with tempering, 3 heats @ two hours slow heat up and cool and 24hrs between.

The multiple quench, amoung other things, allows for full transormation at minimal soak times. This avoids unnecessary grain growth.

Please let us know how your blade works out.
Thanks again for trying the multiple quench and sharing your results.
 
Ed,could you give us the whole process step by step for oil quenching 440c? Also does the triple oil quench work on other air hardening steels that you know of?
Thanks,
Scott
 
Hello Scott: I forged my 440 blades down from two inch ball bearings. I ground them clean, then heated to non magnetic and quenched in 135 degree pre heated texaco type A quenching fluid, letting them cool down in the oil to room temp. I tested blades from one quench to 7 as I remember. Three quenches seemed to be the best bang for the buck. I tempered at 350 degrees they passed the edge flex test, two passes on the steel right and left. They did not cut as good as 5160 forged blades at that time. I did not try all the experiments possible or seek any laboratory assistance. It was fun at the time, and probably they could be taken further. I did not try any rust experiments so do not know if the 'stainless quality' was present.

As you are probably aware I am pretty stuck with the 52100 we are now using. If you should to try some experimenting, I would strongly suggest that after some initial trials, obtain some steel accompanied with a chemistry, quality rating and be sure you can get more of the same. It doesn't take much difference in chemistry to drastically influence your results. I had to learn that lesson the hard way.

The door is wide open for any experiments you would like to try. Joe Szialski has been forging D-2 for some time and suggested that I play with some D-2 and should have some soon. Should you decide to explore, I would like to hear of your travels.
 
Kile, I did the triple quench on a 440c blade last summer and it has proved to be a excellent blade.I did it because i needed a fillet knife for a fishing trip and did not have time to send it out for heat treat.I subjected it to numerous test which it passed.Left the knife with a quide for the remainer of the season and received numerous orders for a blade like it.However trying to duplicate it has proved not very good, tryed in again today and found i had to go considerable above non magnetic like mike and qib suggested. I feel that to get good results consisttly will require some further evaluation.I'm am filling my orders with S30V pro treated.However it was the original post by Ed that encourged me to try it and it resulted in knife sales so i ended up happy... Will mirror polish a blade tomorrow and post results of finish..
 
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