Chemistry: 5160= C- 0.56-0.64 Si- 0.15-0.35 Mn- 0.75-1 P- .0.035 Max S- .040 Cr- 0.7-0.9 SUP9= C- 0.52-0.60 Si- 0.15-0.35 Mn- 0.65-0.95 P- .0.035 Max S- .035 Max Cr- 0.65-0.95 Forging: between 1205 °C and 870 °C Normalizing: Heat to 870 °C. Cool in still air. Annealing: For a predominately pearlitic structure, heat to 830 °C, then cool rapidly to 705 °C, then cool to 650 °C at a rate not exceeding 11 °C per hour; or heat to 830 °C, cool rapidly to 675 °C, and hold for 6 hr. For a predominately spheroidized structure, heat to 750 °C, cool rapidly to 705 °C, then cool to 650 °C at a rate not exceeding 6 °C per hour; or heat to 750 °C, cool rapidly to 675 °C, and hold for 10 hr. Hardening: Austenitize- Heat to 830 °C. Quench in Houghton's G Quench oil. Tempering: As-quenched hardness of approximately 63 HRC. Hardness can be brought down, and toughness increased by tempering as per the following information. Following are tempering temperatures, based on steel that has been hardened to industrial standards. Knifemakers using their own methods will obtain less hardness for the same tempering temperatures.
For more information on heat treating blades, ABS Mastersmith Kevin Cashen has an excellent site: http://www.cashenblades.com/info.html
|Tempering Temperature||Rockwell Hardness|