10-16-2018, 12:39 AM
What happens to hardness if a blade is tempered more than once?
That depends on temperature and time tempering 2x 20min @ 180°C should result in the same hardness as tempering once for 40min @ 180°C
And lastly, how long does a blade have to be at tempering temperature to make a difference? What if the blade only reaches tempering temperature for a few seconds and then was allowed to air cool?
Hollomon–Jaffe parameter is propablywhat you should look at although I do not know where you would get the steel specific parameter at the moment.
https://en.wikipedia.org/wiki/Hollomon%E..._parameter
That depends on temperature and time tempering 2x 20min @ 180°C should result in the same hardness as tempering once for 40min @ 180°C
And lastly, how long does a blade have to be at tempering temperature to make a difference? What if the blade only reaches tempering temperature for a few seconds and then was allowed to air cool?
Hollomon–Jaffe parameter is propablywhat you should look at although I do not know where you would get the steel specific parameter at the moment.
https://en.wikipedia.org/wiki/Hollomon%E..._parameter