CPM S30V HT sample:

R

rlinger

Joined
Mar 29, 2002
Messages
4,591
Okay, here is my latest HT of s30v:

Place in cool oven (foil wrapped blade)

Ramp to 1550 F. - soak 9 minutes (equalize)

Ramp to 1950 F. - soak 28 minutes

Rapid air quench to bare hand cool enough (300 - 350 F. ??)

Still air cool to room temp.

Deep cryo - 16 hours

Triple temper @ 625 F. - 2 hours 15 minutes each temper (still air cool to room temp. between temper cycles)

Lightly grind off heat discolorization

Rockwell tested at Douglas Barrel: RC 58

I am pleased but feel if my 'rapid air quench' was more rapid I could have gained a RC point.

I derived this example from a post on HT'ing s30v by Paul Boss some time back. My above example is very close to his recommendation. I cut my soak time down by two minutes because of the rather slow ramp of my oven at higher temp's, I added the equalization step, and I went long on cryo time (although he did specify 8+ hours for cryo.); his cryo was specified at -280 F. - mine is about -320 F.. Also, my temper cycles are 15 minutes longer (just a thing with me that I like to do).

Roger
 
Roger,
Have you tried pressing them between thick (3/4 or 1") aluminum plates for the rapid quench? It will raise it a point, and it helps keep them flat.
 
Kit,

I have been advised about that before, except I think that chap used steel plates instead of alumunum. Can I get the plates pressed against the blade bevels??? That is the only reason I have shyed away from trying that (thinking I would have a big air gap between the plates and beveled flat grind).

Please advise (remember, I use foil wrap too).

Roger
 
Roger,
I don't wanna pick nits here, but if you grab a 300-350 degree F blade, I'm thinking you'd be dropping that suckah PDQ and heading for the cold water tap at the nearest sink really fast! YIKES!!:eek::eek::eek:

BTW,
Thanks for posting the recipe!
 
Roger,
I initially tried it with steel (fine pole mag chuck & steel plate) and got the same results as with air quench. I use the aluminum plates on all the "S" steels and it works good for me.
I grind after heat treat, so yes, you might have a problem with the bevels. I use foil also but only heat treat up to 4 blades at a time.
The aluminum plates were recommended by Crucible when I was having a problem with 3V and I just carried them over to these steels. Makes for a fast quench.
 
Misque,

I see where I easily gave the impression of picking it up by bare hand at 300 - 350. That is where I guessed it was at when ceasing the the forced air flow over it. At that point I let it still air cool to room temp., before handling it by hand.

Kit,

I better stick with grinding before HT until I get a whole lot more experience. There should be a way though to vise grip a couple sheets of metal against the flat grinds for quenching. I'll have to revisit that from time to time.

Thanks.

Roger
 
After hardening a 1980F, I use the interrupted oil quench like Crucible reccommends, then snap temper at 400F for 2 hrs, followed by treatment on dry ice overnight and then two 400F tempers for 2 hrs each.
This treatment is for hunting and bird and trout knives.
The blades come out damn near bullet proof.
 
Roger, Kit, and Shgeo,

Does Kevin Cashen's description of heat treating using salt sound like it's applicable to knife blades? Go down to the post titled "It’s alive! It’s alive! Ha hahahah!"

http://forums.swordforum.com/showthread.php?s=&threadid=13809&perpage=25&pagenumber=7

It certainly sounds fun. I'm curious how he would differentially heat treat (I assume he can't with this method), and I'm curious why he wouldn't use cryo (don't O1 and L6 both benefit?).
 
I quench between 2, 3 inch thick aluminum plates. For faster quench chill the plates. Leave the knife in the foil wrap and put on bottom plate, then put the top plate on and stand on it for a minute. Mostly I grind after heat treat as well.
 
dont know much about the stuff above, but I do know you can crank the hardness up a couple of points and still have a very tough knife.
 
I've been clamping in between the jaws of a woodworker's vise. I think I'll try the aluminumn plate method though....

Tom, that may be true but it didn't keep my father (he's a BUTCHER I tell you! :rolleyes:) from snapping the tip off one of my folders last year. That one may not have been as well tempered though.
 
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