Alloy N，Hastelloy N Tube，UNS N10003

British Specs:，American Specs: AMS 5771 Bar and Forging AMS 5607 Sheet, Strip and Plate，German Specs:

Alloy N (Hastelloy N Wire, UNS N10003) - Introduction with Composition, Properties, Applications and Product Forms

Alloy N, commercially known as Hastelloy N with the UNS designation N10003, is a nickel-molybdenum-chromium superalloy specifically engineered for exceptional resistance to molten fluoride salts and high-temperature corrosion, along with excellent thermal stability and fabricability. This high-performance material is available in a comprehensive range of forms to meet specialized industrial needs, including Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Hastelloy N Wire, in particular, offers unique flexibility for intricate applications in corrosive and high-temperature environments, such as nuclear and chemical processing systems. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The precisely formulated chemical composition of Alloy N (Hastelloy N, UNS N10003) is the foundation of its superior performance in molten salt and high-temperature corrosive environments. The typical composition (by weight) is as follows:

Nickel (Ni): 65-70% (primary matrix element, providing a stable base for corrosion resistance and high-temperature stability)

Molybdenum (Mo): 15-18% (a critical component for resistance to molten fluoride salts and reducing environments, enhancing high-temperature strength)

Chromium (Cr): 7-9% (improves oxidation resistance and stability in oxidizing environments, balancing the alloy’s performance)

Iron (Fe): 4-6% (aids in fabricability and mechanical stability at ambient temperatures)

Carbon (C): ≤ 0.08% (controlled to minimize carbide formation, preserving ductility and resistance to intergranular corrosion)

Silicon (Si): ≤ 1.0% (assists in deoxidation during manufacturing and enhances oxidation resistance)

Manganese (Mn): ≤ 1.0% (improves fabricability and prevents hot cracking during welding)

Cobalt (Co): ≤ 1.0% (aids in solid solution strengthening and thermal stability)

Trace elements: Phosphorus (P) ≤ 0.04%, Sulfur (S) ≤ 0.03% (kept low to ensure weldability and grain boundary strength)

This balanced composition synergistically delivers the alloy’s signature resistance to molten fluoride salts, high-temperature corrosion, and formability, making it ideal for specialized nuclear and chemical applications.

Key Properties

Alloy N (Hastelloy N Wire, UNS N10003) and its various forms exhibit a robust set of properties that make them indispensable in molten salt environments and high-temperature corrosive applications:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 690-830 MPa (100,000-120,000 psi)

Yield strength (0.2% offset): 310-410 MPa (45,000-60,000 psi)

Elongation (in 50 mm): 30-40% (excellent ductility, enabling complex forming and welding across all product forms)

Hardness: 190-230 HB (Brinell hardness, indicating good machinability)

High-Temperature Performance:

Thermal stability: Maintains significant strength up to 1000°C (1832°F), with tensile strength remaining above 340 MPa at 800°C (1472°F)

Creep resistance: Exhibits excellent creep resistance at 650-850°C (1202-1562°F), critical for long-term service in molten salt reactors and high-temperature systems

Molten salt resistance: Exceptional resistance to corrosion by molten fluoride salts (e.g., LiF-BeF₂-ZrF₄), a key attribute for nuclear reactor applications

Thermal fatigue resistance: Good resistance to thermal cycling, making it suitable for applications with frequent temperature fluctuations

Corrosion Resistance:

Molten salt environments: Superior resistance to attack by molten fluoride and chloride salts, even at elevated temperatures (600-800°C/1112-1562°F)

High-temperature corrosion: Resistant to oxidation, sulfidation, and carburization in industrial environments up to 900°C (1652°F)

Chemical resistance: Good resistance to reducing acids (e.g., hydrochloric acid) and organic chemicals; moderate resistance to oxidizing acids

Wet corrosion: Resistant to seawater, brines, and industrial chemicals, including alkaline solutions

Physical Properties:

Density: 9.1 g/cm³ (0.329 lb/in³)

Thermal conductivity: 11 W/(m·K) at 20°C (68°F), increasing to 19 W/(m·K) at 1000°C (1832°F)

Melting point: 1330-1380°C (2426-2516°F)

Coefficient of thermal expansion: 12.8 μm/(m·K) (20-100°C), rising to 17.5 μm/(m·K) at 1000°C (1832°F)

Modulus of elasticity: 215 GPa (31,200 ksi) at room temperature, decreasing to 165 GPa (23,900 ksi) at 1000°C (1832°F)

Product Forms

Alloy N (Hastelloy N, UNS N10003) is manufactured in a diverse range of forms to accommodate specialized industrial processes, particularly in nuclear and chemical sectors:

Bar: Available as Round bar (diameters from 8 mm to 300 mm) and Flat bar (thickness 6 mm to 150 mm, width 20 mm to 600 mm), ideal for machining into reactor components, valve stems, and high-temperature fasteners.

Ribbon: Thin, flat strips (thickness 0.1 mm to 2 mm, width 5 mm to 100 mm) used in electrical heating elements and seals for molten salt systems.

Wire: Hastelloy N Wire (diameters 0.05 mm to 10 mm) offers excellent flexibility for forming thermocouple sheaths, sensor leads, and woven mesh for filtration in corrosive environments.

Rods: Solid cylindrical rods (diameters 3 mm to 50 mm) suitable for structural supports in nuclear reactors and high-temperature chemical processing equipment.

Tube and Pipe: Seamless and welded options (outer diameter 6 mm to 200 mm, wall thickness 0.5 mm to 20 mm) for transporting molten salts, corrosive fluids, and coolants in reactor systems.

Foil: Ultra-thin sheets (thickness 0.01 mm to 0.1 mm) used in lightweight thermal barriers and corrosion-resistant liners for precision components.

Plate and Sheet: Flat forms (plate: thickness 5 mm to 100 mm; sheet: 0.3 mm to 5 mm) for fabricating reactor vessel liners, heat exchanger panels, and chemical processing tanks.

Strip: Narrow, flat strips (thickness 0.1 mm to 3 mm, width 10 mm to 200 mm) for precision manufacturing in gaskets, seals, and electrical components for corrosive systems.

Forging Stock: Billets and ingots for hot forging into complex shapes such as reactor internals, pump impellers, and valve bodies for molten salt service.

Applications

The exceptional properties of Alloy N (Hastelloy N Wire, UNS N10003) across its various forms make it a critical material in industries requiring resistance to molten salts and high-temperature corrosion:

Nuclear Energy:

Molten Salt Reactors (MSRs): Core components such as fuel channels, heat exchanger tubes, and reactor vessel liners (from plate, sheet, and tube) — leveraging superior resistance to molten fluoride salts.

Nuclear fuel processing: Equipment for handling radioactive molten salts, including transfer pipes (from tube) and processing tanks (from plate).

Radiation shielding components: Structural parts (from bar and forging stock) that maintain integrity under radiation and high temperatures.

Chemical Processing:

Molten salt processing: Pipes and vessels (from tube, pipe, and plate) for handling molten fluoride or chloride salts in industrial processes, such as aluminum smelting.

High-temperature chemical synthesis: Reactors and catalyst supports (from plate and sheet) for processes involving corrosive reagents at elevated temperatures.

Acid production: Components for handling hydrofluoric acid and other aggressive chemicals, including pumps and valves (from bar and forging stock).

Industrial and Energy:

Solar thermal power systems: Heat exchanger tubes (from tube) and absorber plates (from sheet) for concentrated solar power (CSP) systems using molten salt as a heat transfer fluid.

Waste incineration: Components exposed to corrosive ash and high temperatures, such as furnace liners (from plate) and exhaust ducting (from sheet).

Metallurgical processing: Crucibles and stirring rods (from forging stock and rod) for handling molten metals and salts.

Specialized Applications by Form:

Wire: Thermocouple sheaths in molten salt reactors, sensor leads in high-temperature chemical plants, and woven filters for corrosive fluid filtration.

Tube/Pipe: Molten salt transport lines in MSRs and solar thermal systems, chemical process piping, and heat exchanger tubes.

Plate/Sheet: Reactor vessel liners, heat exchanger panels, and tank walls in corrosive and high-temperature environments.

Bar/Rod: Machined fasteners, valve stems, and structural supports for nuclear and chemical processing equipment.

In summary, Alloy N (Hastelloy N Wire, UNS N10003) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional resistance to molten salts, high-temperature corrosion, and thermal stability. Its diverse product forms enable tailored solutions across nuclear energy, chemical processing, and industrial sectors, establishing it as a critical material in extreme corrosive and high-temperature applications.

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 2876 gallon liquid totes Special package is available on request.