temper

[butcher_block]

i have some cpm3v on the way but while i know i need to foil wrap for heat treat but i see the tempering temp is 1000 should i wrap for the temper also
thanks

 

[rlinger]

I would. Never had the nerve not to at that and above. Won't hurt except for another dollar in foil wrap. I always foil wrap my steel when stress relieving (about 1200 F - there-abouts).

For this steel I would ramp my tempering oven slowly to 1000 F and a block of steel in the oven to help stabilize temperature would be good. Although not as steep as BG-42, 3V has a sharp tempering curve. Hold as close to desired temperature as you can.

RL

 

[butcher_block]

sharp curve going to have to help me on that one
plan so far is to
preheat 1500 5 min
ramp to 1950 hold for 30 min
plate quench
3 tempers at 1000 maybe 1115
its 3v and its just a hair thicker then 7/32 should i soak longer then 30 min maybe im used to working steel in the 1/8 inch range
it looks like this will put it at hrc of 59 i was thinking about tring to bring it down a point more but im not sure
btw im going off the crucible data sheet for temps and times ive been hearing there spot on
thanks

 

[rlinger]

Sharp curve: it does not take much of a temperature increase to make a relatively large change in hardness.

I'd go closer to a 20 minute soak for that blade.

Here are two 3V blades I did not long ago:

Preheat: 1525 F / 7 min.
Austenitize: 1950 / 22 min.
Rapid air quench
Snap temper: 300 / 1 hr
Deep cryo: 13 hr
Temper: 1000 / 2 hr
Temper: 990 / 2 hr
Temper 990 / 2 hr

Tested hardnesses after final temper: 60 HRc and 59 - 59.5 HRc
-------------------------

RL

 

[butcher_block]

can i deep cryo after the first temper or is that a waste
it seems to be not easy to get dry ice or LN for me round here

 

[rlinger]

Yes, or snap temper then cryo. If snap tempering (300 to 350 F) do two tempering cycles after cryo.

RL

 

[butcher_block]

thanks again now i just have to find that dry ice
have you found that cryo takes the steel up about 2 points Rc just incase i cant do cryo i want to know my ballpark hardness

 

[butcher_block]

update just looked at the bottle opener i made with the scrap 3v cleaned it up after quench it has a hair line crack in it i think im going to temper it the full 3 times with the blade that was done at the same time i just hope i didnt crack the blade also

 

[butcher_block]

got 2 tempers done but due to time and place of my workshop i needed to start the handle 3rd heat will be done tonight