ASTM B637 UNS N07718 Nickel Alloy Inconel 718 for High Temperature
N07718 is a Ni-Cr-Mo alloy designed to resist a wide range of
severely corrosive environments, pitting and crevice corrosion.
It displays exceptionally high yield, tensile, and creep-rupture
properties at high temperatures. This nickel alloy is used from
cryogenic temperatures up to long term service at 1200° F(650°C).
One of the distinguishing features of N07718’s composition is the
addition of niobium to permit age hardening which allows annealing
and welding without spontaneous hardening during heating and
cooling. The addition of niobium acts with the molybdenum to
stiffen the alloy’s matrix and provide high strength without a
strengthening heat treatment. Other popular nickel-chromium alloys
are age hardened through the addition of aluminum and titanium.
This nickel steel alloy is readily fabricated and may be welded in
either the annealed or precipitation (age) hardened condition.
|Weight(%)||0.08 max||0.35 max||0.35 max||0.015 max||0.015 max||17.0–21.0||1.0 max||2.80–3.30||4.75–5.50||0.65–1.15||0.20–0.80||0.006 max||remainder||0.30 max||50.0–55.0|
- Good mechanical properties – tensile, fatigue and creep-rupture
- Yield tensile strength, creep, and rupture strength properties are
- Highly resistant to chloride and sulfide stress corrosion cracking
- Resistant to aqueous corrosion and chloride ion stress corrosion
- High temperature resistant
- Age-hardenable with a unique property of slow aging response that
permits heating and cooling during annealing without the danger of
- Excellent welding characteristics, resistant to postweld age
- Chemical processing
- Liquid fuel rocket motor components
- Pollution-control equipment
- Nuclear reactors
- Cryogenic storage tanks
- Valves, fasteners, springs, mandrels, tubing hangers
- Well head completion equipment and blow out preventers (BOP’s)
- Gas turbine engine parts