Help heat treating my s35

D

DukeHarley

Joined
Apr 11, 2014
Messages
644
Actually have a couple questions. Last night I used my new Evenheat for the first time to HT some s35. Had some issues happen that I've never had happen before. First off when I was finished plate quenching I had a problem getting the tool wrap off the blades. It literally vacuumed itself to the blades and I had to peel it off the blades. Never had that before. Any ideas what happened?

Also I checked them straight off the plates and I was only at 59-60? My process was heat oven to 1600 and put blades in. Soak for 5 min then ramp at 1500 to 1950 and soak for 30 min then straight on to the plates. Not sure why I'm so low. Check after first temper at 2 hours at 400 and I'm at 57-58. Any ideas what I did wrong or why I'm so low?

Any help is appreciated.
 
Your numbers show that it took over two hours to heat up to 1950 from 1600. That is far too long.I would change your protocol to ramp from 1600 to 1950 at 9999. Otherwise, the numbers are not significantly off for S35V. A bit low, but not excessively. I suspect when you grind the blade clean, it will test harder.

The foil will sometimes stick to the blade when pressed if it has had a very long soak, which yours did. The press plates force the hot metal together and it sort of welds. No issues.
 
Ahhh......ok Stacy. I'll ramp at 9999 from now on. I've always had a buddy do it for me or me just use his oven and his schedules for the HT.

Thank you!

Jay
 
If you throw a little bit of talcum (baby powder) inside your foil pouch it will prevent your blade from sticking to the foil.

If you cryo or do a dry ice treatment right after your plate quench and before your temper, the blade will be harder.
 
Last edited:
S.Alexander said:
If you throw a little bit of talcum (baby powder) inside your foil pouch it will prevent your blade from sticking to the foil.

If you cryo or do a dry ice treatment right after your plate quench and before your temper, the blade I'll be harder.
Click to expand...

Yep. I do the talc treatment and it works well. I try to keep it really thin so it doesn't slow the plate quench down too much. Or depending on the blade shape, I might put a tiny bit of paper in there, which also seems to help. I'd definitely freeze the blade if you can. S35VN is expensive, might as well try to get the most out of it.
 
Thank guys! Yes I did an alcohol and dry ice bath for 15-20 min straight off the plates. Well......as soon as I was able to get the tool wrap off.

Jay
 
I use similar technique as others to keep foil from stick to blade - wipe foil inside with lightly oil/canola dampened paper towel then smear talc on surface.

I suspect your blade has low hardness because of high RA%. Use the chart below as a rough guide - just lower the hardness curve by 2.5-3rc.

Capture.JPG

During 1900F-1950F ramp + first 10 minutes of 1950F soak times (say 30 minutes total), with continuous ramping radiant heat the blade easily heated over 2050F. At this high soak temperature, your blade (aust matrix) over saturated with carbon in solution and stay that way until temperature drops below CrC precipitation for s35vn (wag ~1800F). So remaining soak time at 1950F does essentially nothing. 309 Foil stuck to your blade is a solid indication of over-heated blade foil envelope.

A solution to achieve ~62rc AQ hardness without cold quench(DI or LN2):

seg1: 2000F ramp 9999 cold oven hold 2 hrs
after 60-70 minutes; put foiled blade into oven; skip to seg2

seg2: 1950F ramp 9999 hold 40 minutes
quench blade after 25-35 minutes 1950F soak
 
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