Inconel 718

Synopsis

Inconel 718 is a high strength nickel alloy that has the capability to be precipitation hardened which helps keep its resistance, strength, oxidation, and ductility while in the most extreme environments. This performance must be kept constant during long periods at high temperatures, which is fulfilled by the Inconel series. It is used in many industries for their critical applications including aerospace, oil and gas, chemical, and valves. Premium Alloys stocks Inconel 718 in 3 conditions: AMS 5662, AMS 5663, and NACE MR0175 (API 6A CRA).


Resistance

Inconel 718 has beneficial protection to atmospheric decay and corrosion at climates within the nickel alloys strength space. It has somewhat favorable weldability, formability, and exceptional low temperature properties comparable to other PH nickel alloys. In the NACE MR0175 form, Inconel 718 has a required minimum yield strength of 120 KSI. It is processed differently than the AMS conditions to enhance its corrosion resistance in downhole tools and completion components. AMS 5663 has a minimum yield strength of 150 KSI which makes it suitable for applications that require intense strength in both the aerospace and oil & gas industries.


Processing

Inconel 718 requires particular heat treatment solutions, hinging on what the intended final need is for the component. The approach is particular for either attaining the greatest tensile/yield strength and force-fracture properties for extreme temperature operations or for augmenting the benefits for use at room or freezing temperatures. AMS 5662 is considered the annealed condition and is the precursor to AMS 5663. Inconel 718 NACE calls out for a different annealing temperature and chemistry while maintaining a hardness range from 32 – 40 HRC. Each condition has specific uses depending on the application.


Physical Properties:

Condition
Tensile Yield Enlongation Reduction
of Area
Hardness
NACE 150KSI 120KSI 20% 35% 32-40 HRC
AMS5663 185KSI 150KSI 12% 15% 331 BHN min

Applications

  • Aerospace
  • Oil and Gas
  • Valves
  • Chemical
  • Jet Engines
  • Fasteners
  • Aircrafts
  • 3D Printing
  • Gas Turbine Engines
  • Cryogenic Tanks

Benefits

  • Excellent corrosion and oxidation resistance in harsh environments
  • Very strong with high mechanical properties
  • Good durability and ductility
  • Significant volume of iron, diminishing Inconel 718's cost per kg while enhancing its strength with precipitation hardening.
  • Inconel 718 keeps robust resistance to corrosion up to 1000°C.
  • Nickel alloys combat chloride-ion stress-corrosion cracking and protects from corrosion in many oxidizing compounds