HT'ing 2nd time Quench

[KenH]

Hello ya'll. I've got a real newbie question here. I'm sure many of ya'll watch "FiF" from time to time. Yes, I KNOW FiF is NOT, I repeat NOT the place to learn knifemaking. It's entertainment - and sometimes there are a few tidbits to pick up.

FiF judges seem to always say quenching for the 2nd (or 3rd) time is really bad and causes poor HT. My question is why? Let's face it, a blade direct from forging has the metal in about as poor condition for HT'ing as can be asked.

Provided the blade is normalized prior to next HT and Quench. It seems like by soaking at 1600°F or so for a few minutes. Then a couple more heats at descending temps the metal should be back at good condition for HT'ing.

I would be interested to hear comments from ya'll, especially you Ed.

[Doug Lester]

Well, I'm not Ed but I pretty much agree with your conclusion. If you miss the hardening you want with a blade then you need to try again. I don't know about repeated normalizations after a failed hardening because you didn't grow the grain on the previous quench unless you way over heated the blade preparing it for the quench. Depending on the alloy that you're working with, I would worry about over normalizing the blade and reducing the grain size too much and reducing hardenability. However, if that does occur, you can soak at a high temperature to increase the size of the grain and start the heat treatment over.

Doug

[KenH]

Doug, Thanks for the comment and I fully respect your knowledge and experience as well as ED. For what it's worth, I agree with your comments 100%.