Annealing 15N20

Chris Railey

Chris Railey

Well-Known Member
I have made three or four knives with 15N20 now and I like it a lot. The problem I have is with it shearing teeth off of my bandsaw blades. I figured "no big deal I will anneal it". Heated it to dull orange and left it in the forge, closed her up and turned her off. The next day I cut more and it did not seem to help much. Am I missing something here?
 
I can't say exactly what's going on with yours.

I've had good luck just heating it to critical and letting it air cool a few times. Just thermal cycling a few times rather than any annealing type procedure, has allowed me to saw it, drill it and machine it with no issues.
 
Thanks, I will give that a try. By the way do you plate quench 1/8 inch and thicker or do you harden in oil?
 
15N20 can air harden I believe. You may want to try getting it up to nonmagnetic temp, 1560 I think, and letting it slow cool in vermiculite. Another option could be to local heat right before cutting but I would research that further.
 
Due to the nickel content, there is air hardening qualities in 15N20. Generally it needs to be well annealed in something like vermiculite, or in a heat treat oven for reliable annealing. Try what Redbaird mentioned, and if that doesn't do it, it will likely take the controlled environment of a heat treat oven..... simply because 15N20 has variance in the nickel content.....it will USUALLY anneal via Redbaird's method.......but not always.

Personally, if I'm cutting up 15N20, the chopsaw is the tool to us...... even if it is fully annealed, the edges will often rip teeth off a bandsaw blade. ;)
 
Redbaird said:
15N20 can air harden I believe. You may want to try getting it up to nonmagnetic temp, 1560 I think, and letting it slow cool in vermiculite. Another option could be to local heat right before cutting but I would research that further.
Click to expand...
This was what I had to do to get mine where I could drill it.
 
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