Alloy 718 / UNS N07718 Nickel Alloy Steel Seamless Pipe and Tube

AMS 5589 AMS 5590

Due to its high-temperature strength up to 700 °C (1300 °F), excellent corrosion resistance and ease of fabrication ALLOY718 finds applications in many fields. Initially it was used as a turbine disk material in aircraft jet engines. Here resistance to creep and stress rupture was most important.

Because of its properties, fabricability and cost effectiveness it has since gained wider acceptance. To-day applications vary from highly stressed rotating and static components in gas turbines and rocket engines to high-strength bolting, springs and fasteners, components in nuclear reactors and space vehicles as well as high-temperature tooling for extrusion, of for example copper, and shearing. Another more recent important application involves pump shafts and other highly stressed well head and downhole components in offshore and marine engineering. Particularly useful is the alloy for drilling equipment in sour (containing H2S, CO2 and chlorides) oil and gas wells.

Material Summary

Inconel 718 is a Gamma Prime strengthened alloy with excellent mechanical properties at elevated temperatures, as well as cryogenic temperatures. Suitable for temperatures upto around 1300 F. Can be readily worked and age hardened.

Excellent strength from -423 degrees F to 1300 degrees F (-253 degrees C to 705 degrees C). Age hardenable and may be welded in fully aged condition, Excellent oxidation resistance up to 1800 degrees F (980 degrees C). Typically sold in the solution annealed temper, but can be ordered aged, cold worked, or cold worked & aged.

The high chromium and molybdenum contents of Alloy 718 impart excellent resistance to uniform and localized corrosion, such as pitting in many media at both high and low temperatures. The chromium also enables it to withstand chloride-ion stress-corrosion cracking which makes it an excellent alloy for service in oil and sour gas (H2S containing) environments as well as seawater.
Alloy 718 is generally only used for applications not exceeding 700 °C (1300 °F). However, oxidation resistance up to 1000 °C (1830 °F) is particularly high and comparable to that of other gamma-prime (γ’) strengthened superalloys