Which stainless steels for knife making do not require a cryro treatment for optimal performance.
He lowers the austenizing temperature to ~1900 degrees F, oil quenches, and tempers at 380 degree F range, and maintains a hardness above 60 HRc, specifically with AEB-L. The amount of retained austenite when quenched from 1900 F to room temperature was minimal, 6% or less. Oil quenching is recommended.
A dry ice/acetone bath will get cold enough to take care of the RA..I measured our last batch at -106°..I isn't cold enough for "true" cryo but you will generally get the same RC gains from the RA reduction as you do with LN from what Ive seen. Just not the cryo's eta carbide" formation..
- Furnace: Vacuum, protective gas, or salt bath
- Preheat 1: 450-600°C equalize 3-5 min
- Preheat 2: 850-950°C equalize 3-5 min
- Austenize: 1065°C eqalize 3-5min, hold 5min
- Quench: oil preheat to 60°-80°C; N2 4bar
- Cryo 1: immediately after quench min. -70°C or lower, hold 1h
- Temper1: 150°C for 1h, then quench in Water
- Cryo 2: immediately after quench min. -70°C or lower, hold 1h
- Temper 2: 150°-180°C for 1h, then quench in Water