Alloy 260， Fittings，UNS N03260

British Specs:，American Specs: AMS 5890 Bar and Forgings，German Specs:

Alloy 260 (Wire, UNS N03260) - Introduction with Composition, Properties, Applications and Product Forms

Alloy 260, identified by the UNS designation N03260, is a high-performance nickel-based alloy celebrated for its exceptional corrosion resistance in a wide range of environments, including both oxidizing and reducing conditions, along with impressive mechanical strength and excellent formability. This versatile material is available in an extensive array of forms to cater to diverse industrial requirements, such as Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Alloy 260 Wire, in particular, stands out for its flexibility and precision, making it ideal for intricate applications like electrical components, precision springs, and filtration systems in corrosive settings. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The carefully balanced chemical composition of Alloy 260 (UNS N03260) is the cornerstone of its superior performance in various corrosive and demanding environments. The typical composition (by weight) is as follows:

Nickel (Ni): 95-97% (serves as the primary matrix element, providing a stable foundation for corrosion resistance and structural integrity)

Chromium (Cr): 2.0-3.0% (enhances oxidation resistance by forming a protective oxide layer, especially in high-temperature environments)

Iron (Fe): 0.5-1.5% (improves fabricability and mechanical stability at both ambient and elevated temperatures)

Molybdenum (Mo): 0.5-1.5% (boosts resistance to pitting and crevice corrosion in chloride-rich environments)

Copper (Cu): 0.3-0.7% (aids in resistance to sulfuric acid and other reducing acids)

Manganese (Mn): ≤ 0.5% (assists in deoxidation during manufacturing and improves weldability)

Silicon (Si): ≤ 0.3% (minimized to reduce the formation of brittle phases while aiding in oxide layer formation)

Carbon (C): ≤ 0.03% (controlled to prevent carbide precipitation, preserving ductility and corrosion resistance)

Trace elements: Phosphorus (P) ≤ 0.02%, Sulfur (S) ≤ 0.01% (kept at low levels to ensure weldability and grain boundary strength)

This well-engineered composition synergistically delivers the alloy's signature combination of corrosion resistance, mechanical strength, and formability, making it suitable for a broad spectrum of industrial applications.

Key Properties

Alloy 260 (Wire, UNS N03260) and its various forms exhibit a robust set of properties that render them indispensable in corrosive, high-temperature, and high-stress environments:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 600-750 MPa (87,000-108,800 psi)

Yield strength (0.2% offset): 250-350 MPa (36,300-50,800 psi)

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

Hardness: 150-190 HB (Brinell hardness, indicating good machinability and wear resistance)

High-Temperature Performance:

Thermal stability: Maintains significant strength up to 800°C (1472°F), with tensile strength remaining above 300 MPa at 600°C (1112°F)

Creep resistance: Exhibits good creep resistance at 500-700°C (932-1292°F), making it suitable for long-term service under sustained stress in high-temperature systems

Oxidation resistance: Resistant to oxidation in air and combustion gases up to 1000°C (1832°F), forming a dense, self-healing chromium oxide layer

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

Corrosion Resistance:

Broad-spectrum resistance: Exceptional resistance to both oxidizing acids (e.g., nitric acid) and reducing acids (e.g., sulfuric acid, hydrochloric acid in dilute forms)

Chloride resistance: Superior resistance to pitting and crevice corrosion in chloride-rich environments, including seawater, brines, and industrial effluents

Wet corrosion: Resistant to alkaline solutions, organic acids, and industrial chemicals, ensuring versatility across diverse industries

Stress corrosion cracking (SCC): Highly resistant to SCC in chloride-containing environments, even at elevated temperatures

Physical Properties:

Density: 8.9 g/cm³ (0.321 lb/in³)

Thermal conductivity: 15 W/(m·K) at 20°C (68°F), increasing to 22 W/(m·K) at 800°C (1472°F)

Melting point: 1430-1480°C (2606-2696°F)

Coefficient of thermal expansion: 13.5 μm/(m·K) (20-100°C), rising to 17.0 μm/(m·K) at 800°C (1472°F)

Modulus of elasticity: 210 GPa (30,500 ksi) at room temperature, decreasing to 160 GPa (23,200 ksi) at 800°C (1472°F)

Product Forms

Alloy 260 (UNS N03260) is manufactured in a diverse range of forms to accommodate specialized industrial processes across chemical, aerospace, marine, and electrical 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 valve components, pump shafts, 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, gaskets, and seals for corrosive equipment.

Wire: Alloy 260 Wire (diameters 0.05 mm to 10 mm) offers excellent flexibility and precision, making it suitable for precision springs, thermocouple leads, woven mesh filters, and electrical connectors in corrosive environments.

Rods: Solid cylindrical rods (diameters 3 mm to 50 mm) suitable for structural supports in chemical reactors, aerospace components, and high-temperature machinery.

Tube and Pipe: Seamless and welded options (outer diameter 6 mm to 200 mm, wall thickness 0.5 mm to 20 mm) for transporting corrosive fluids, including acids and industrial chemicals, in processing systems.

Foil: Ultra-thin sheets (thickness 0.01 mm to 0.1 mm) used in lightweight corrosion barriers, thermal insulation, and precision electronic 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, storage tanks, heat exchanger panels, and aerospace structural parts.

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

Forging Stock: Billets and ingots for hot forging into complex shapes such as pump impellers, valve bodies, and aerospace engine components.

Applications

The exceptional properties of Alloy 260 (Wire, UNS N03260) across its various forms make it a critical material in industries requiring resistance to diverse corrosive environments, high temperatures, and mechanical stress:

Chemical Processing:

Acid production and handling: Tanks, pipes, and valves (from plate, tube, and bar) for processing and transporting both oxidizing and reducing acids, ensuring long-term reliability.

Pharmaceutical manufacturing: Equipment for producing high-purity chemicals, including reaction vessels (from plate) and transfer lines (from tube), maintaining product integrity and corrosion resistance.

Fine chemical synthesis: Reactor internals (from forging stock) and heat exchangers (from tube and sheet) for processes involving complex chemical environments.

Aerospace and Aviation:

Gas turbine engines: Combustion chamber components (from sheet and plate), turbine blade retainers (from forging stock), and heat shields (from foil) leveraging high-temperature stability.

Aerospace instrumentation: Precision springs and electrical connectors (from wire and strip) resistant to corrosive atmospheres and temperature fluctuations.

Rocket propulsion systems: Components exposed to high-temperature exhaust gases, such as nozzles (from forging stock) and thermal insulation (from foil).

Marine and Offshore:

Shipbuilding: Hull components, seawater intake systems, and propeller shafts (from plate, sheet, and bar) resisting seawater corrosion.

Offshore platforms: Piping systems (from tube) for seawater injection, processing equipment (from plate), and structural supports (from rod) exposed to salt spray.

Desalination plants: Heat exchanger tubes (from tube) and pressure vessels (from plate) for seawater desalination, withstanding chloride-induced pitting.

Electrical and Electronics:

Electrical components: Wire for thermocouple leads, connectors, and heating elements in corrosive environments, ensuring consistent performance.

Battery systems: Components for high-performance batteries, resisting corrosion from electrolytes and ensuring long service life.

Electronic enclosures: Plates and sheets for protective enclosures in harsh environments, safeguarding sensitive electronics.

Specialized Applications by Form:

Wire: Precision springs in chemical pumps, thermocouple sheaths in industrial furnaces, woven filters for acid filtration, and electrical leads in corrosive environments.

Tube/Pipe: Chemical transport lines, heat exchanger tubes in power plants, and sampling lines for aggressive fluids.

Plate/Sheet: Reactor vessel liners, storage tank walls, and aerospace structural panels resistant to both corrosion and high temperatures.

Bar/Rod: Machined valves, pump shafts, and fasteners for corrosive environments where strength and reliability are critical.

In summary, Alloy 260 (Wire, UNS N03260) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional versatility in resisting diverse corrosive environments, along with high-temperature stability and formability. Its diverse product forms enable tailored solutions across chemical processing, aerospace, marine, and electrical sectors, establishing it as a critical material in complex industrial 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 2815 gallon liquid totes Special package is available on request.