Alloy 903，Incoloy 903 Rod，

British Specs:，American Specs:，German Specs:

Alloy 903 and Incoloy 909 Wire (UNS N19909) - Introduction with Composition, Properties and Applications

It's important to note that Alloy 903 and Incoloy 909 (UNS N19909) are distinct nickel-based superalloys, each with unique characteristics. Here's a detailed introduction to both, including their chemical compositions, properties, and applications.

Alloy 903

Chemical Composition

Alloy 903 is a nickel-iron-cobalt superalloy with a carefully balanced composition (by weight) to achieve its specific properties:

Nickel (Ni): 38-42%

Iron (Fe): 34-38%

Cobalt (Co): 14-18%

Niobium (Nb) + Tantalum (Ta): 4.0-5.0% (Nb typically constitutes the majority)

Molybdenum (Mo): 2.5-3.5%

Titanium (Ti): 1.0-1.5%

Aluminum (Al): 0.5-1.0%

Carbon (C): 0.03-0.08%

Trace elements: Silicon (Si) ≤ 0.30%, Manganese (Mn) ≤ 0.30%, Phosphorus (P) ≤ 0.015%, Sulfur (S) ≤ 0.015%

Key Properties

Mechanical Properties (room temperature):

Tensile strength: 1030-1170 MPa (150,000-170,000 psi)

Yield strength (0.2% offset): 760-860 MPa (110,000-125,000 psi)

Elongation: 15-20%

Hardness: 30-35 HRC

High-Temperature Performance:

Maintains good strength up to 650°C (1200°F)

Excellent creep resistance at intermediate temperatures

Low coefficient of thermal expansion, making it suitable for applications with thermal cycling

Physical Properties:

Density: 8.0 g/cm³ (0.289 lb/in³)

Thermal conductivity: 16 W/(m·K) at 20°C (68°F)

Coefficient of thermal expansion: 11.0 μm/(m·K) (20-650°C)

Applications

Alloy 903 is widely used in industries where low thermal expansion and high strength are crucial:

Aerospace: Fasteners, gas turbine components, and structural parts in aircraft and spacecraft

Defense: Missile systems and other high-performance military applications

Industrial: Tooling for high-temperature processes and precision components requiring dimensional stability

Incoloy 909 Wire (UNS N19909)

Chemical Composition

The carefully formulated chemistry of Incoloy 909 (UNS N19909) is key to its exceptional performance. The typical composition (by weight) includes:

Nickel (Ni): 40-45% (primary matrix element)

Iron (Fe): 30-35% (balances the alloy and enhances stability)

Cobalt (Co): 15-20% (improves high-temperature strength)

Molybdenum (Mo): 3-5% (boosts creep resistance and corrosion performance)

Titanium (Ti): 1.5-2.5% (aids in forming strengthening precipitates)

Aluminum (Al): 0.5-1.5% (works with titanium to create gamma-prime (γ’) phases)

Trace elements: Carbon (C), Silicon (Si), Manganese (Mn), and Chromium (Cr) in controlled amounts (<0.5% total) to optimize grain structure and weldability.

This blend forms a robust metallic matrix reinforced by intermetallic γ’ precipitates during heat treatment, which are critical for maintaining strength at temperatures up to 650°C (1200°F).

Key Properties

Incoloy 909 Wire exhibits a unique combination of mechanical and thermal properties that set it apart in high-stress environments:

Mechanical Properties (at room temperature, annealed condition):

Tensile strength: 1000-1200 MPa (145,000-174,000 psi)

Yield strength (0.2% offset): 700-850 MPa (101,500-123,300 psi)

Elongation (in 50 mm): 15-25% (excellent ductility for fabrication)

Hardness: 28-32 HRC (after aging treatment)

High-Temperature Performance:

Creep resistance: Maintains <0.2% creep deformation after 1000 hours at 650°C (1200°F) under 300 MPa (43,500 psi) stress.

Thermal stability: Retains >80% of room-temperature strength at 600°C (1112°F).

Oxidation resistance: Forms a protective oxide layer in air up to 800°C (1472°F), preventing rapid degradation.

Physical Properties:

Density: 8.1 g/cm³ (0.292 lb/in³)

Thermal conductivity: 15-18 W/(m·K) at 20°C (68°F)

Coefficient of thermal expansion: 12-14 μm/(m·K) (20-600°C)

Applications

The unique properties of Incoloy 909 Wire (UNS N19909) make it indispensable in industries requiring reliability under extreme heat and stress:

Aerospace & Defense:

Aircraft engine components: Turbine blade retainers, combustion chamber liners, and exhaust system fasteners.

Rocket propulsion systems: High-temperature gaskets and thermocouple sheaths for fuel delivery systems.

Structural parts in supersonic vehicles: Springs and connectors exposed to thermal cycling.

Power Generation:

Gas turbine hot-section components: Valve stems and seal wires in turbine casings.

Steam turbine systems: Welded wire mesh for heat exchanger screens.

Industrial & Advanced Engineering:

High-temperature furnaces: Heating element supports and thermocouple protection tubes.

Nuclear energy: Control rod drive mechanisms (resistant to radiation-induced embrittlement).

Petrochemical processing: Welded wire components for catalytic reactors operating at 500-600°C (932-1112°F).

Packing of Standard Packing:

 Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3016 gallon liquid totes Special package is available on request.