when to quench

R

rlinger

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Mar 29, 2002
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So far during my learning experiences I have been quenching my O-1 steel straight out of the forge as quickly as I could get it into the oil. Though I have not been able to Rockwell test after tempering I have been pleased by how the files skip over. However, am I correct in quenching as soon as possible or is it better to allow the color to leave the steel first? No write ups I have speak of this. I suppose I am looking for a general answer but the steel in question is O-1.

Thanks again
 
I am not sure, I am new to this also, but from what I have gathered, if you want ot attain full hardness you need to quench very soon after pulling the blade out of the heat. I think I read somwhere it had to be in under two seconds? I test my blades with the magnet, wait about 10 seconds after they are non magnetic, and as fast as I can I quench them. It seems to work for me.
Kyle Fuglesten
 
I make all of my folders out of 01. What makes the blade hard is when it is quenched from its highest temp which would be as soon as it comes out of the forge. Some people normalize their blades before heat treating them. To normalize a blade, you bring it up to critical temp, (just above magnetic,) remove it from the forge and let it air cool until it looses it's color. This is usually done three times. It will not harden your blade, but it will help the grain. After quenching 01, I temper it in an oven at 375 for 1 hour. I then let it cool to room temp, and temper it again for another hour.

Hope this helps. -chris
 
My understanding is that hardening takes place within 4sec after it hits the oil. Correct me if this is wrong.
But the steel needs to hit the Quench at Critical temp to properly harden.
Cool to about 150deg F, immediatly go for the first temper usually 1/2 hr, this is called a Snap temper. Cool to room temp slowly, do any Cryo then temper again usually twice.
Got all that:D
 
Outstanding! Thanks fellows. I did presume that since my tech sheets did not specify the default should be to quench immediately. It may take me about 3 to 4 seconds to get it into the oil (I have chosen 140 degrees F. for my oil for O-1). I will take your advise as a general answer not specific to O-1 only, unless tech sheets for a particular steel specify differently.

I am now tempering at aprox. 365 F./60 min and for the second temper aprox. 340 F./60 min. (O-1) for 1/8 to 0.100 inch thich blades/tangs. If this seems out of line please advise

I am pleased.

Thanks for the fast responce.
 
Hi !
I have also a small question about this subject:

It is necessary to make the tempering immediately after the heat treating or I can take the time to remove scales and clean the blade before ? I read that is necessary to hurry to do the tempering, that is really critical?

Also, which hardness you advise me for small-medium knife and for large ones? (I work with O-1)

Thanks !

AMD
 
Well you pretty much always remove the scale so you can see that pretty straw color dontcha? How safe this is I think depends on the speed of the oil used in the quench and the shape of the blade.

I have tried a few quenching media with O1 from water (don't of course) to motor oil. The one in water broke when I skidded the file accross it. The motor oil one hardened more than any knife I have but was softer than the file. I have not tempered it and I use it everyday with satisfaction.

I'm currently following the instructions of wiser heads, however - see above and other threads on the same subject like http://www.bladeforums.com/forums/s...id=163500&highlight=heat+treating+temperature
 
As for me and the small folders that I make, tempering is the last thing I do before putting the knife together. By finishing the blade prior to tempering it, it's easier to see the blade turns a straw color when tempered.

-chris
 
Robert, thanks for the note about the cryo. I've used the poor man's dry ice / acetone quench a couple of times, after my first temper and tempering again after the cryo. That's the vindication I needed, always wondered whether I had it right.

For what it's worth, I think the dry ice quench adds value. A wood carver says his CO2-quenched knives stay sharper a lot longer and keeps telling me I'm missing a lucrative market. :) I guess it's a good thing I don't do this for money!

Dave
 
Everything I read indicates that the blade must be in the quinching medium before the temperture "passes the nose" of the hardening process. The temp reducing begins as soon as the blade leaves the forge.
While at the JC Campbell school, Don Fogg had us pratice moving the blade from the forge to the water so we could do it guickly and without too much movement that would bend the blade.

Also Wayne Goddard in his books comments several times that it's important to temper as soon as possible. I'm not sure of the reasons behind this. It could be that he doesn't want you to try to strighten a non-tempered blade and have it break, like a couple I have nailed to the wall of the shop.
Learning, Lynn
 
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