First heat treating - cautionary tale, warping...

A

AKShooter907

Joined
Sep 26, 2017
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Hello, mainly wanted to just say thanks for all the info I've got here. And total novice here, but just completed my first round of tempering Nitro V. Went okay...

End of the day, this was 3/32" material. I generally did most of my grinding before heat treat. The smaller blades turned out okay, but some of the longer kitchen knives have warping. Most not terrible, but enough its not going to grind out. Learning moment here. Already going to go at it again with just profiled blades, then HT. Give that a go.

I think my big reason for warping could have been non-symmetrical grinding. I'm also wondering if I really got them cool enough in the plates. Just working with a pancake compressor that was bogging down pretty good. Certainly could just handle with gloved hands, pretty sure I was down to 125 or so, should have grabbed the heat gun.

Anyway, I'll keep trying, lol. Think I can still salvage some out of the batch though!

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What steel? Warping is part of the game, steel will keep moving through the grinding, especially for thin kitchen knifes.

Check out all the info on carbide straightening hammers here, there has been couple of threads recently.
 
Stress releaving step before heat treat helps immensely. 1200F for 2 hours with oven cool.

I like to drop my clamped plates into bucket of cold water to cool everything off. Some have said that by doing this it also helps keep blank straight as it cools below room temperture in plates.

I did the above on a recent batch of 50 AEB-L blanks that were 0.080 inches thick and only 3 of the blanks needed to be slightly straightened with carbide peening hammer.
 
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Thanks. I wish I would have looked at them better out of the foil and quench. They looked pretty good before the dry ice cryo. I just saw something about cryo sometimes causing warping. But going to try another round of the longer kitchen knives, grinding post HT
 
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