Aogami Super Carbon Steel Clad with Stainless Steel DPS San Mai (.12" x 29" x 1-1/2")

Product Description for Aogami Super Carbon Steel Clad with Stainless Steel DPS San Mai (.12" x 29" x 1-1/2")

Maker: Takefu Special Steel (click to see more by this maker)
Price: $159.78
Item num: 108284
Total length: 29.00 in.
Item weight: 23.80 oz.
Size: .12" x 29" x 1-1/2"
Description: This bar is Aogami Super (Blue Super) carbon steel core with stainless steel cladding, laminated by Takefu Special Steel in Japan. DPS (depletion prevention system) adds a thin nickel shim between the core steel and the cladding. The nickel acts as a barrier to stop carbon migration between the carbon steel core and stainless steel outer layers and creates a particularly dramatic and bold transition line.
The Aogami Super carbon steel core contains very few impurities and is easy to heat treat. In addition to containing more carbon, chromium, and tungsten than Aogami 1. Tungston and chromium are added to improve heat treatment properties and chip resistance. The resulting knife will have exceptional edge sharpness and edge retention and is capable of attaining high harness without being brittle. It has good ductility, workability, and is easily forged. Hard and fine carbides are formed by adding Cr (Chromium), W (Tungsten), and V (Vanadium), ensuring tremendous durability and edge holding. The addition of W (Tungsten) brings about high toughness and high strength at elevated temperatures. V (vanadium) ensures fine grain. These effects are even more enhanced with the addition of Cr (Chromium). Although ease of quenching and improved annealing are rarely found together, precise amounts of Mn (manganese) and Cr (chromium) gives this desired effect. Because of the high toughness of Aogami Super, it can be used at extremely high hardness, Hrc 65 in culinary knives, and 60-61 Hrc in sporting knives. 

Aogami Super Specs
C Si Mn P S Cr W V
1.4-1.5% .1-.2% .2-.3% .025% .004 .3-.5 2-2.5 .3-.5%

Heat Treatment
Forging: Forge at 1100°C/2012°F. Do not forge below 1000°C/1832°F. You should anneal after forging.
Annealing: Anneal at 750-780°C/1382-1436°F. Cooling speed should not exceed 25°C/hr - 77°F/hr
Quenching: Austenitize at 780-830°C/1436-1526°F. Quench in oil (50°C/122°F)
Tempering: Temper at 160-230°C (320-446°F) to desired hardness.

Annealed: Hrc 25
Hardened: Hrc 66.5
Sub-Zero: Hrc 67.0

Mastersmith Bill Burke's Heat Treatment Recommendation: After forging, thermal cycle blade a minimum of three times.
A full or subcritical anneal should then be done, which contributes to a finer grain structure. Anneal at 1400°F, hold 30 minutes, then cool at 77°F per hour to 750°F. then air cool. If desired a sub-critical anneal can be used in place of a full anneal. Soak two hours at 1250°F then cool at 75°F per hour to 750°F, then shut off annealing oven and allow to cool in oven.
When ready to harden, heat to between 1436 and 1526°F. Hold only long enough to make sure the blade is at uniform temperature and quench. I recommend quenching in oil at the higher temperature range (approx 1525°F). Temper two times for two hour each (320-446°F) to bring steel to desired hardness.

V-Toku2 Heat Treatment Chart

Note: results may vary with hardening method and section size.

Availability: In stock. Usually ships in 1-2 business days