N07718 is the Unified Numbering System (UNS) designation for a nickel-based alloy most commonly known as Inconel 718. The UNS system was created by a number of trade groups working together in the 1970’s, to reduce confusion from the same alloy being called different things or vice-versa. Each metal is indicated by a letter followed by five numbers, where the letter indicates the family of metals i.e. N for nickel-based alloys.
Alloy 718 (UNS N07718, 2.4668) is a high-strength, corrosion-resistant nickel chromium alloy. The additions of Nb, Ti and Al form a series of precipitates with Ni during the controlled solution annealing and ageing process steps, resulting in a significant increase in strength and hardness of this alloy compared with alternative nickel alloys. It can be supplied in a variety of different strength levels or conditions, depending upon the extent of the ageing heat treatment. The most common strength level is a yield strength greater than 120ksi, although a 150ksi variant has also been developed.
The alloy is widely used in the Oil and Gas and chemical production industries on account of its high strength and resistance to chlorides, stress corrosion and sulphide stress cracking. Applications include valve trim, pump shafts and down-hole components. Alloy 718 is also used in jet engine and high-speed airframe parts such as wheels, spacers and buckets plus high-temperature bolts and fasteners, although more commonly supplied against the AMS 5662/AMS5663 aerospace standards rather than API 6CRA for this application.
Inconel is a trademark of Special Metal Inc, covering a family of nickel-chromium alloys.
For more information about nickel-based alloys, please don’t hesitate to contact us today. We would be happy to answer any questions that you may have regarding specifications and common applications. We stock N07718 from 1/2″ (12.7mm) to 10″ (254mm) diameter solid bar.