Chemical Composition, %

Mechanical Properties

Age hardening heat treatment:

Age hardening shall be accomplished by holding at an aim temperature of 1100°F (595°C) for 8 to 16 h followed by furnace cooling to 900°F (480°C) at a rate of 15 to 25°F (10 to 15°C) per hour and then air cooling. An alternate procedure consists of holding at 1100°F (595°C) for up to 16 h, furnace cooling to 1000°F (540°C), holding for approximately 6 h, furnace cooling to 900°F (480°C), holding for approximately 8 h, and air cooling to room temperature.

(Mill age-hardened products have been precipitation heat treated by the manufacturer and further thermal treatment normally is not required. Hot-worked, cold-worked, or annealed material is normally age hardened by the purchaser after forming or machining.)