ThePipingMart Blog Grades AMS 5581 Inconel Alloy – Composition, Properties and Uses

AMS 5581 Inconel Alloy – Composition, Properties and Uses

AMS 5581

Many materials are used in various industries, and one that has recently been gaining attention is AMS 5581. This material has unique properties, making it an attractive choice for different applications. But what is AMS5581? This blog post will closely examine the composition, physical and mechanical properties, uses, hardness, and heat treatment of AMS 5581.

What is AMS 5581?

AMS 5581 (also known as Inconel 625 Alloy) is a high-temperature alloy commonly used in aerospace applications. This alloy is known for its excellent strength and durability, making it a popular choice for critical components in aircraft engines and other high-performance machinery. It comprises a combination of metals, including nickel, cobalt, and chromium, which provide outstanding resistance to high temperatures and corrosion. If you are looking for a reliable and long-lasting material for your next aerospace project, AMS5581 is worth considering. Its superior properties make it a top choice for engineers and manufacturers alike.

What Forms Is AMS 5581 Available at Piping Mart?

  • Nut
  • Bar
  • Bolt
  • Pipe
  • Screw
  • Tubing
  • Valves
  • Washers
  • Flanges
  • Fasteners
  • Electrodes
  • Stud Bolts
  • Sheet Plates
  • Pipe Fittings
  • Forged Fitting

AMS 5581 Composition

AMS 5581 is a high-temperature nickel-based alloy used in gas turbine engine components. Its composition comprises 20% chromium, 15% molybdenum, 10% cobalt, and 5.2% aluminium. The alloy primarily aims to provide high strength and maintain creep resistance at elevated temperatures.

NI 58.0 min
AL 0.40 max
FE 5.0 max
MN 0.50 max
C 0.10 max
SI 0.50 max
S 0.015 max
P 0.015 max
CR 20.0 – 23.0
NB + TA 3.15 – 4.15
MO 8.0 – 10.0
TI 0.40 max

AMS 5581 Physical Properties

One of the physical properties of AMS 5581 is its specific gravity, which is 8.33 grams per cubic centimetre. It is also nonmagnetic and has excellent oxidation and corrosion resistance properties. The material can withstand corrosion even in harsh environments such as seawater.

DENSITY 8.44 g/cm 3 / 0.305 lb/in 3
MELTING POINT 1290 -1350 (°C) / 2350 – 2460 (°F)
SPECIFIC HEAT @ 70°F 0.098 Btu/lb/°F
CURIE TEMPERATURE -190 (°C) / < -320 (°F)
YOUNG’S MODULUS (N/MM2) 205 x 10
ANNEALED 871 (°C) / 1600 (°F)
QUENCH Rapid Air

AMS 5581 Mechanical Properties

AMS 5581’s mechanical properties are also noteworthy. The alloy has a tensile strength of 196 ksi and a yield strength of 117 ksi. Additionally, it can maintain its power even at temperatures as high as 1200°F. Its elongation at break is 12%, meaning it can bend and stretch slightly before breaking.

PROPERTY 21°C 204 °C 316 °C 427 °C 538 °C 649 °C 760 °C 871 °C
Ultimate Tensile Strength /Mpa 992.9 923.9 910.1 910.1 896.3 820.5 537.8 275.8
0.2% Yield Strength /MPa 579.2 455.1 434.4 420.6 420.6 413.7 406.8 268.9
Elongation % 44 45 42.5 45 48 34 59 117
Coefficient of Thermal Expansion µm/m⁰C 13.1 13.3 13.7 14 14.8 15.3 15.8
Thermal Conductivity /kcal/(hr.m.°C) 8.5 10.7 12.2 13.5 15 16.4 17.9 19.6
Modulus of Elasticity/ MPa 2.07 1.93 1.93 1.86 1.79 1.65 1.59

AMS 5581 Equivalent

5581 2.4856 N06625 NCF 625 ХН75МБТЮ NA 21 NC22DNB4MNiCr22Mo9Nb NiCr23Fe

AMS 5581 Uses

The unique combination of AMS 5581’s physical and mechanical properties makes it suitable for various applications. Its corrosion and oxidation resistance, for instance, make it an ideal choice for marine and aerospace industries—the alloy’s strength and toughness suit high-pressure and high-temperature applications, such as gas turbine engine components.

AMS 5581 Hardness

AMS 5581’s hardness is also worth noting. Its Brinell hardness is around 241, which is relatively high. However, the alloy’s high hardness does not come at the expense of its flexibility. It remains bendable and can be forged, machined, or welded.

AMS 5581 Heat Treatments

Lastly, AMS 5581 requires specific heat treatments to maximize its properties. After being hot-worked and forged, it needs to be annealed at 2100°F. This process will make the alloy soft again and improve its ductility. Solution annealing, ageing treatments, and stress relieving are also recommended to achieve the alloy’s desired properties.


In conclusion, AMS 5581 is a high-temperature nickel-based alloy with unique physical and mechanical properties. Its composition includes 20% chromium, 15% molybdenum, 10% cobalt, and 5.2% aluminium. It has excellent resistance to corrosion and oxidation, making it a suitable material for various applications. Its high strength, toughness, flexibility, and hardness make it an attractive choice for high-temperature and high-pressure applications. Proper heat treatment is essential to maximize the material’s properties. Overall, AMS 5581 is a versatile and reliable material that competes well with other high-performance alloys.

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