Alloy 801，Incoloy 801 Wire，UNS N08801

British Specs:，American Specs: AMS 5552 Sheet, Strip and Plate，German Specs:

Alloy 801 and Incoloy 801 Wire (UNS N08801) - Introduction with Composition, Properties and Applications

Alloy 801, commercially recognized as Incoloy 801 with the UNS designation N08801, is a nickel-iron-chromium superalloy celebrated for its exceptional resistance to high temperatures, corrosion, and creep. Available in various forms, including the versatile wire format (Incoloy 801 Wire), this alloy is a staple in industries where reliability under extreme conditions is non-negotiable. Below is a detailed breakdown of its chemical composition, key properties, and practical applications.

Chemical Composition

The precise chemical makeup of Alloy 801 (Incoloy 801, UNS N08801) is engineered to deliver its signature performance. The typical composition (by weight) is as follows:

Nickel (Ni): 30-35% (forms the primary matrix, enhancing corrosion resistance and structural stability)

Iron (Fe): 39-44% (balances the alloy and improves mechanical strength at ambient temperatures)

Chromium (Cr): 19-23% (a critical element for oxidation resistance, forming a protective oxide layer at high temperatures)

Molybdenum (Mo): 2.5-3.5% (boosts creep resistance and strengthens the alloy at elevated temperatures)

Copper (Cu): 1.0-1.5% (enhances resistance to sulfuric acid and other corrosive media)

Titanium (Ti): 0.15-0.6% (aids in grain refinement and precipitation strengthening)

Aluminum (Al): 0.15-0.6% (works with titanium to form intermetallic precipitates, improving high-temperature strength)

Carbon (C): ≤ 0.05% (controlled to minimize carbide formation, which can reduce ductility)

Trace elements: Silicon (Si) ≤ 1.0%, Manganese (Mn) ≤ 1.0%, Phosphorus (P) ≤ 0.025%, Sulfur (S) ≤ 0.015% (optimize weldability and fabricability)

Key Properties

Alloy 801 and Incoloy 801 Wire (UNS N08801) exhibit a robust set of properties that make them ideal for harsh environments:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 550-650 MPa (79,800-94,300 psi)

Yield strength (0.2% offset): 200-250 MPa (29,000-36,300 psi)

Elongation (in 50 mm): 30-40% (excellent ductility, facilitating easy forming and welding)

Hardness: 140-180 HB (Brinell hardness, indicating good machinability)

High-Temperature Performance:

Thermal stability: Maintains mechanical integrity up to 800°C (1472°F), with tensile strength remaining above 300 MPa at 650°C (1200°F).

Creep resistance: Exhibits minimal deformation under sustained stress at 600-700°C (1112-1292°F), making it suitable for long-term high-temperature service.

Oxidation resistance: Resists scaling in air and combustion gases up to 900°C (1652°F) due to its chromium content, which forms a dense, adherent oxide layer.

Corrosion Resistance:

Excellent resistance to sulfuric acid, phosphoric acid, and other industrial chemicals.

Resists chloride-induced stress corrosion cracking (SCC) in moderate environments, outperforming many stainless steels.

Good resistance to aqueous corrosion, including seawater and brackish water.

Physical Properties:

Density: 8.0 g/cm³ (0.289 lb/in³)

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

Coefficient of thermal expansion: 16.0 μm/(m·K) (20-100°C), increasing to 19.0 μm/(m·K) at 800°C (1472°F)

Melting point: 1370-1400°C (2500-2552°F)

Applications

Alloy 801 and Incoloy 801 Wire (UNS N08801) find widespread use across industries that demand high-temperature resilience and corrosion resistance:

Chemical Processing:

Acid production: Components in sulfuric acid plants, such as heat exchangers, pump shafts, and valve trim, where resistance to aggressive acids is critical.

Chemical reactors: Liners and agitators for processes involving corrosive media like phosphoric acid and organic compounds.

Power Generation:

Nuclear industry: Fuel cladding, steam generators, and heat exchanger tubes in nuclear power plants, thanks to its radiation resistance and corrosion performance.

Fossil fuel power plants: Boiler tubes, superheater elements, and flue gas desulfurization systems, where exposure to high temperatures and sulfur-rich environments is common.

Oil & Gas:

Downhole equipment: Tubing, casings, and connectors for sour gas wells, resisting hydrogen sulfide (H₂S) and chloride corrosion.

Refining: Catalyst support grids, heat exchanger tubes, and distillation column internals in petroleum refining processes.

Aerospace & Industrial:

Aerospace: Exhaust system components and high-temperature fasteners in aircraft engines, where thermal cycling resistance is essential.

Industrial furnaces: Heating elements, furnace liners, and thermocouple sheaths, leveraging its oxidation resistance at extreme temperatures.

Wire-Specific Applications (Incoloy 801 Wire):

Welded mesh and screens for high-temperature filtration in chemical and food processing.

Thermocouple wires and lead wires for temperature measurement in corrosive environments.

Springs and clips in industrial machinery operating at elevated temperatures, benefiting from the wire’s ductility and strength.

In summary, Alloy 801 (Incoloy 801 Wire, UNS N08801) stands out as a versatile superalloy, combining high-temperature stability, corrosion resistance, and excellent fabricability. Its wire form further expands its utility, making it a go-to material for intricate, high-performance components across critical industries.

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 3014 gallon liquid totes Special package is available on request.