Multiple heat treating

C

colewaldron@rocketma

Joined
Feb 8, 2016
Messages
5
What happens if you heat treat a sword two or more times? And by heat treat I mean the entire process hardening quenching etc, I ruined a blade on a belt sander it turned blue after removing the burnt steel I plan on re heat treating the entire thing my question is will multiple heat treatments harm or weaken the metal in any way? Thank you
 
First the technical term "burnt steel " is one where the grain boundries have been oxidized == that means the steel can't be used !!
If you're talking about a blue color that's only a thin surface oxide which wouldn't have to be removed . Re heat treating can be done , best by first using a subcritical anneal [ 1200F for two hours ] then proceed in normal HT.
 
You may end up with slightly deeper decarburization, and the more times you do it the more chances of warpage/distortion of curvatures/cracking (the latter depending on quench medium)
Multiple quenches can serve as a substitute for thermal cycling, but it's easier and less warpy/stressy to just thermal cycle.
I have a couple of personal swords that have been HT'd a couple times either because I didn't like the tempering or discovered a section that didn't harden fully. They're fine.
 
Last edited:
You must log in or register to reply here.
Back
Top