Tempering cpm 3v

I was able to Rockwell check my 4 blades and they all checked 59 to 60. The part I left out of my original post was I tempered them at 400F 3 times for 2 hours each time. It will be a while before I can make any kind of determination on how well they actually hold up to real world use but at least I think I'm on the right track. Again, thank you all for all the great info!
 
Wow great thread! I recently have done a bunch of long soak times in liquid nitrogen on cpm M4 , and cpm S90v 24hr soaks just cause the nitrogen was there, it will be interesting to see how they perform.

Question about immediately after the plate quench I Rockwell test the blades, 2-3 min for the tester to cycle then into the liquid nitrogen, is that to long to wait? Is the RA stabilizing in that short window of time.
 
I realized I’m bringing up an old thread but just had a question about some results I’ve got with cpm3v. I heat treated a blade using the following:
Heat oven to 1975 put knife in and soak for 30 min plate quench then in alcohol dry ice overnight. Temper at 400 in kitchen oven twice for 2 hours each. The harness after surface grinding a bit is reading 64 on my ptc 415c tester.

Is this about what others are seeing with this protocol? It seems high to me so kind of questioning my hardness tester, I just bought it used on eBay so it very well could be inaccurate.
 
Unfortunately none of us will be able to tell you whether or not it is accurate, as we can't tell if your hardness tester is accurate!

To properly make use of a hardness tester you must also purchase a calibration standard that will let you know whether your tester is accurate or not, and to adjust it if necessary. You should be able to get one on eBay for a reasonable price... Look for one around 60HRC, as there's not point getting a 40HRC one when you won't be testing near that hardness!
 
The hardness tester I bought came with some test blocks, a 40hrc and a 60. The tester consistently reads 2 points higher when used on those blocks so I assume it’s 2 points high on my blades as well. When I use the tester on the 3v knife blank it reads 66 so accounting for the 2 points high that’s how I got 64. I was just wondering if that hardness was even in the ballpark or if something might be amiss with my tester (maybe the diamond tip is broken? Though it doesn’t appear to be).
 
i have run 3v hard but i dont think i have ever seen it even as quenched over 63 then tempered back to 61-62
 
RC hardness is not a direct linear scale. I don’t know how this affects a hardness tester that’s reading high.
 
William2112 said:
The other night I heat treated 4 blades Im working on. The material is cpm 3v . The procedure I used was I brought them up to 1500F and let equalize for 15 minutes. Fast ramped up to 1975F for 35 minutes. Plate quenched between two 1 inch thick aluminum plates until I was able to touch them. I then snap tempered them at 300F for an hour. Let them cool to room temp and cryo treated them in dry ice and kerosene over night. The tempering temps that Ive been seeing on here for cpm 3v range anywhere from 400F to over 1000F. That seems like a huge range to me. Can anyone please clarify or help explain why there is such a variation in tempering temps. Any insight would be greatly appreciated.
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Read this:

http://www.hypefreeblades.com/forum/viewtopic.php?f=3&t=77&sid=b5200c062d0fddb6d2e10512bed283bd
Roman Landes gives his cpm3v heat treatment recipe and he explains exactly why he recommends it.
 
aarongough said:
Unfortunately none of us will be able to tell you whether or not it is accurate, as we can't tell if your hardness tester is accurate!

To properly make use of a hardness tester you must also purchase a calibration standard that will let you know whether your tester is accurate or not, and to adjust it if necessary. You should be able to get one on eBay for a reasonable price... Look for one around 60HRC, as there's not point getting a 40HRC one when you won't be testing near that hardness!
Click to expand...


I agree with Aaron. I have been using 3v exusively for years....and Brad(Peters) has been doing my heat treating...once again, exclusively! Could do it myself, but would need to build the oven, then play with the heat treat until I could "kinda" match what Brad is giving me. With Brad's latest recipe I'm getting consistent 60-61hrc and the edge retention is extremely high! The blades now are straight up tougher and have much higher wear resistance than what Peter's was doing for me just a few years ago.


Couple things: I believe you need LN Cryo for the highest performance from 3V. 2, I truly believe Brad is the leading authority on heat treatment, but most assuredly with 3v!
 
I’ll reply, I heat treated a 3v blade last night, and got around rc 63 after quench. Brought oven up to 1950, put blades in, and started my 30 minute soak, plate quenched till cool, took out of foil, when they were cool to the touch, I put them in the freezer for about 20 minutes, then into the dewar. Only did 30 minutes in cryo, then tempered at 400 x 3. I’m getting right at 60 rc. This was my first shot at 3v. We’ll see how it tests!
 
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