Alloy 718, also known as Inconel 718 is a precipitation-hardening nickel-chromium alloy containing significant amounts of iron, columbium, and molybdenum, along with lesser amounts of aluminum and titanium. Alloy 718 maintains high strength, good ductility and is suitable for temperatures up to around 1300 F. This alloy has relatively good weldability, formability, and excellent cryogenic properties compared to other precipitation hardening nickel alloys. The sluggish precipitation hardening response of this alloy allows it to be readily welded without hardening or cracking.
Uses for Inconel 718 tend to be in the field of gas turbine components and cryogenic storage tanks. Jet engines, pump bodies and parts, rocket motors and thrust reversers, nuclear fuel element spacers, hot extrusion tooling. Other popular uses are high strength bolting, and down hole shafting.