ThePipingMart Blog Grades Alloy AL 201 (UNS N02201) – Composition, Properties, and Uses

Alloy AL 201 (UNS N02201) – Composition, Properties, and Uses

Alloy AL 201

If you are in the metal industry, you must have heard of alloy AL 201. It’s a low-carbon nickel alloy that offers superb resistance to corrosion, extreme temperatures, and harsh chemicals. This alloy is widely used in various applications, including chemical processing, nuclear reactors, valves and fittings, and many others. This post will discuss alloy AL 201 composition, mechanical and physical properties, uses, corrosion resistance, and welding. So let’s dive in.

Alloy AL 201 Composition

Alloy AL 201 is a wrought nickel alloy with a maximum low carbon content of 0.02%. It also contains 0.50% copper, 0.02% sulfur, 0.015% carbon, 0.10% iron, 0.25% manganese, 0.35% silicon, and 99.0% nickel. These elements contribute to the alloy’s high corrosion resistance and strength properties.

Element Content (%)
Nickel, Ni 99.9
Silicon, Si 0.05
Iron, Fe 0.05
Manganese, Mn 0.02
Copper, Cu 0.02
Carbon, C ≤ 0.020
Sulfur, S 0.002

Alloy AL 201 Mechanical Properties

Alloy AL 201 has impressive mechanical properties, including high tensile strength, yield strength, and ductility. It boasts a tensile strength of 93 ksi and a yield strength of 48 ksi. Its elongation at break ranges from 45 to 55%. Furthermore, alloy AL 201 has outstanding thermal conductivity, making it suitable for high-temperature applications.

Properties Metric Imperial
Tensile strength (typical annealed) 403 MPa 58500 psi
Yield strength (at strain 0.200%, typical annealed) 103 MPa 14900 psi
Elastic modulus 207 GPa 30000 ksi
Shear modulus 81 GPa 11700 ksi
Poisson’s ratio 0.31 0.31
Elongation at break (typical in 2″, annealed) 50% 50%
Hardness, Rockwell B (typical annealed) 45 45

Alloy AL 201 Physical Properties

The physical properties of alloy 201 also make it an ideal material for use in harsh environments. It has a density of 8.89 g/cm3 and a melting point of 1435°C. It also has a coefficient of expansion of 13.34×10^-6 K^-1, which makes it resistant to thermal stress cracking.

Properties Metric Imperial
Density 8.90 g/cm³ 0.322 lb/in³
Melting point 1427°C 2600°F

Alloy AL 201 Thermal Properties

Properties Metric Imperial
Thermal expansion co-efficient (at 27-93°C/80.6-199°F) 13.3 µm/m°C 7.39 µin/in°F
Thermal conductivity (at 100°C/212°F) 67.1 W/mK 466 BTU in/hr.ft².°F

Alloy AL 201 Equivalents

  • AMS 5553
  • ASTM B160
  • ASTM B161
  • ASTM B162
  • ASTM B163
  • ASTM B366
  • ASTM B725
  • ASTM B730
  • DIN 2.4061
  • DIN 2.4068

Alloy AL 201 Uses

The range of properties exhibited by alloy AL 201 makes it an excellent choice for various applications. Its high resistance to acids and alkalis makes it suitable for chemical processing plants. It is also used in petrochemical, nuclear power plants, and paper manufacturing industries. Alloy 201 is also used in various components of aerospace vehicles due to its high corrosion resistance.

Alloy AL 201 Corrosion Resistance

Alloy AL 201 is known for its excellent performance in reducing and oxidizing environments. It is highly resistant to stress corrosion cracking, pitting, and crevice corrosion.

Alloy AL 201 Welding

Additionally, alloy 201 is suitable for welding using the most common techniques. It is recommended to use the same nickel alloy filler metal when welded to avoid any deterioration in corrosion resistance.


To sum up, Alloy AL 201 is a special nickel alloy that offers incredible resistance to harsh environments. It is used extensively in various applications because of its excellent mechanical and physical properties. This nickel alloy’s corrosion resistance and weldability make it an ideal choice for many industries. But it’s critical to note that it’s essential to understand the alloy’s composition in every application to ensure maximum performance. If you are looking for a reliable metal supplier, choose a certified supplier for high-quality alloy AL 201.

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