ThePipingMart Blog Grades Nimonic Alloy 901 (UNS N09901) – Composition, Properties and Uses

Nimonic Alloy 901 (UNS N09901) – Composition, Properties and Uses

Nimonic 901 (UNS N09901)

Nimonic 901 is a nickel-based high-temperature alloy with excellent mechanical and physical properties and impressive corrosion resistance. It is a popular choice of material in industries that demand high strength, durability, and heat resistance. In this blog post, we will delve into the composition, properties, uses, and fabrication techniques of Nimonic 901.

Nimonic 901 Composition

Nimonic 901 is formulated with nickel, chromium, titanium, and aluminium, among other elements. The alloy contains 42% nickel, 18% chromium, 5% titanium, 2.6% aluminium, and 1.6% iron, among other components. Adding these elements in precise proportions enhances the material’s mechanical and thermal properties, making it suitable for aerospace, nuclear, chemical, and petrochemical applications.

Element Content (%)
Nickel, Ni 40-45
Iron, Fe 33
Chromium, Cr 11-14
Molybdenum, Mo 5.0 – 6.50
Titanium, Ti 2.80-3.10
Cobalt, Co 1
Manganese, Mn 0.50
Copper, Cu 0.50
Silicon, Si 0.40
Aluminum, Al 0.35
Carbon, C 0.10
Sulfur, S 0.030

Nimonic 901 Mechanical Properties

Nimonic 901 boasts exceptional mechanical properties, such as high tensile and yield strength, excellent fatigue and creep resistance, and excellent ductility, even at high temperatures. The alloy can withstand temperatures up to 650 degrees Celsius, making it ideal for components exposed to extreme heat and stress. In addition, Nimonic 901 retains its mechanical strength and dimensional stability at elevated temperatures, making it suitable for use in gas turbines, rocket engines, and furnace components.

Properties Metric Imperial
Tensile strength (precipitation hardened, value at room temperature) 1200 MPa 174000 psi
Yield strength (@strain 0.200%, precipitation hardened, value at room temperature) 875 MPa 127000 psi
Elongation at break (precipitation hardened) 15% 15%

Nimonic 901 Physical Properties

With a density of 7.97 g/cm³, Nimonic 901 has good physical properties such as high thermal conductivity, low thermal expansion, and exceptional resistance to thermal shock. The material’s thermal conductivity is 12.4 W/(m*K), and its coefficient of thermal expansion is 12.4 µm/m•K, making it an excellent choice of material for applications that require high-temperature insulation, such as furnace linings.

Properties Metric Imperial
Density 8.14 g/cm³ 0.294 lb/in³
Melting point 1280-1345°C 2340-2453°F

Nimonic 901 Equivalent

The equivalent material to Nimonic 901™ is DIN 2.4662.

Nimonic 901 Uses

Nimonic 901 finds use in several heavy industries, including aerospace, nuclear, chemical, and petrochemical. The alloy fabricates turbine blades, combustion chambers, heat exchangers, valves, and exhaust systems, among other components that require high strength and heat resistance. The superior properties of Nimonic 901 make it an appropriate selection for applications requiring high temperature and mechanical stability.

Nimonic 901 Corrosion Resistance

Nimonic 901 boasts exceptional corrosion resistance, making it an ideal option in extreme environments where corrosive gases cannot be avoided. It exhibits excellent resistance to oxidation and nitriding, ensuring the material remains highly durable even when exposed to harsh chemicals.

Nimonic 901 Heat Treatment

Due to the high nickel and chromium content, Nimonic 901 is somewhat challenging to fabricate. Therefore, it requires a high degree of precision and expertise. Heat treatment and solution annealing are necessary processes during the fabrication of Nimonic 901, as they provide uniform grain size, enhance physical properties and provide localized relief from stresses.

Nimonic 901 Machining

Nimonic 901 presents unique challenges for machinists due to its high nickel content and resistance to deformation. Achieving precise cuts and finishes while maintaining the integrity of the material requires specialized equipment and expertise. Only trained experts should handle the machining of Nimonic 901, and they should be equipped with the knowledge to properly control the material’s thermal properties, cutting forces, and tool wear. With the right tools and expertise, Nimonic 901 can be machined with precision and accuracy.

Nimonic 901 Welding

Nimonic 901 welding requires a certain level of expertise to ensure the highest quality. This nickel-based alloy is known for its ability to withstand high temperatures and resist corrosion, making it a popular choice in the aerospace and gas turbine industries. The welding process requires careful considerations and precise techniques to avoid cracking or brittleness and maintain the integrity of the material. Experienced welders must consider pre-weld preparations, post-weld heat treatments, and specific welding procedures to achieve a solid and durable bond. The possibilities are endless with Nimonic 901’s exceptional properties and the proper welding techniques.


In summary, Nimonic 901 is a high-temperature alloy with exceptional properties, including high strength, heat, and corrosion resistance. The precise combination of materials enhances the physical and mechanical properties and improves its overall durability. The versatility of Nimonic 901 makes it useful for several applications requiring high-temperature and chemical resistance, such as in aerospace, nuclear, chemical, and petrochemical industries. As a result of its excellent properties, several manufacturers continue to incorporate Nimonic 901 into complex components and equipment.

Related Post