Sean Yaw
Gold Member
- Joined
- Feb 26, 2019
- Messages
- 417
I heat treated some S60V slipjoint blades yesterday and got different results from what I expected. I austenitized for 20 minutes at 2100, followed by an hour in LN, followed by two 2-hour tempers at 300. The result was 66.5 HRC (on a calibrated tester). I then walked up the tempering temperature (350, 400, 450, 500) all the way to an hour at 500 and got 63-63.5 HRC. I was not expecting this because the references I have read (Knife Steel Nerds and data sheet) suggested austenitizing at 2050 followed by 400-degree tempers would result in 61-62 HRC and that austenitizing at 2100 followed by 300-degree tempers could result in around 64.5.
I was aiming for 62-63 HRC, so I figured I would austenitize at 2100 and just temper higher to get that. I am worried because tempering at 500 or 550 seems super high and I know that there is a "bad region" to temper in (tempered martensite embrittlement, not that I really understand what that is). Has anyone used a newer batch of S60V and seen similar heat treating results? Do you think I should break a blade to "inspect the grain" (not that I really know what I am doing there) to give myself confidence that resulting knives will be sound? Any insights are appreciated. Thank you.
I was aiming for 62-63 HRC, so I figured I would austenitize at 2100 and just temper higher to get that. I am worried because tempering at 500 or 550 seems super high and I know that there is a "bad region" to temper in (tempered martensite embrittlement, not that I really understand what that is). Has anyone used a newer batch of S60V and seen similar heat treating results? Do you think I should break a blade to "inspect the grain" (not that I really know what I am doing there) to give myself confidence that resulting knives will be sound? Any insights are appreciated. Thank you.
