Alloy 404，Monel 404 Sheet，

British Specs:，American Specs:，German Specs:

Alloy 404 and Monel 404 Wire - Introduction with Composition, Properties, Applications and Product Forms

Alloy 404, commercially known as Monel 404, is a nickel-copper alloy renowned for its exceptional corrosion resistance in reducing environments, excellent machinability, and stable mechanical properties across a range of temperatures. This versatile material is available in a comprehensive array of forms to meet diverse industrial needs, including Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Monel 404 Wire, with its inherent flexibility and precision, is particularly well-suited for intricate applications requiring both corrosion resistance and formability. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The carefully calibrated chemical composition of Alloy 404 (Monel 404) is the foundation of its unique performance characteristics. The typical composition (by weight) is as follows:

Nickel (Ni): 52-57% (serves as the primary matrix element, providing a stable base and contributing to corrosion resistance)

Copper (Cu): 42-46% (enhances machinability and corrosion resistance in reducing environments, such as sulfur-containing solutions)

Iron (Fe): ≤ 0.5% (minimized to optimize corrosion resistance in specific chemical environments)

Manganese (Mn): ≤ 0.1% (controlled to maintain alloy purity and stability)

Carbon (C): ≤ 0.1% (kept low to prevent carbide formation that could impair ductility)

Silicon (Si): ≤ 0.1% (minimized to ensure consistent corrosion performance)

Trace elements: Sulfur (S) ≤ 0.01% (strictly controlled to maintain ductility and weldability)

This lean composition is specifically engineered to balance corrosion resistance, machinability, and structural stability, making it ideal for specialized industrial applications.

Key Properties

Alloy 404 and its various forms, including Monel 404 Wire, exhibit a distinct set of properties that make them valuable in corrosive and precision-focused environments:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 480-550 MPa (69,600-79,800 psi)

Yield strength (0.2% offset): 190-240 MPa (27,500-34,800 psi)

Elongation (in 50 mm): 30-40% (good ductility, enabling forming and welding processes)

Hardness: 120-160 HB (Brinell hardness, indicating excellent machinability)

Corrosion Resistance:

Reducing environments: Exceptional resistance to sulfuric acid, hydrofluoric acid, and other reducing acids, outperforming many nickel-based alloys

Alkaline solutions: Good resistance to caustic environments, including sodium hydroxide, at moderate temperatures

Low-oxygen environments: Stable performance in environments with limited oxygen, such as underground pipelines and closed chemical systems

High-temperature limits: Maintains corrosion resistance in air up to 300°C (572°F), with gradual degradation at higher temperatures

Physical Properties:

Density: 8.9 g/cm³ (0.321 lb/in³)

Thermal conductivity: 24 W/(m·K) at 20°C (68°F)

Melting point: 1290-1340°C (2354-2444°F)

Coefficient of thermal expansion: 14.1 μm/(m·K) (20-100°C)

Modulus of elasticity: 185 GPa (26,800 ksi) at room temperature

Product Forms

Alloy 404 (Monel 404) is produced in a diverse range of forms to accommodate specialized industrial processes and applications:

Bar: Available as Round bar (diameters from 6 mm to 250 mm) and Flat bar (thickness 5 mm to 120 mm, width 15 mm to 500 mm), ideal for machining into precision components like valve stems and chemical pump parts.

Ribbon: Thin, flat strips (thickness 0.08 mm to 1.5 mm, width 4 mm to 80 mm) used in electrical connectors and corrosion-resistant gaskets for chemical equipment.

Wire: Monel 404 Wire (diameters 0.04 mm to 8 mm) offers excellent precision for forming thermocouple wires, fine mesh screens, and small springs in corrosive systems.

Rods: Solid cylindrical rods (diameters 2 mm to 40 mm) suitable for structural supports in chemical processing equipment and laboratory apparatus.

Tube and Pipe: Seamless options (outer diameter 5 mm to 150 mm, wall thickness 0.4 mm to 15 mm) for transporting corrosive fluids in pharmaceutical and chemical industries.

Foil: Ultra-thin sheets (thickness 0.008 mm to 0.08 mm) used in lightweight corrosion barriers and precision electronic components.

Plate and Sheet: Flat forms (plate: thickness 4 mm to 80 mm; sheet: 0.2 mm to 4 mm) for fabricating chemical storage tanks and reaction vessel liners.

Strip: Narrow, flat strips (thickness 0.07 mm to 2 mm, width 8 mm to 150 mm) for precision manufacturing in analytical instruments and chemical processing hardware.

Forging Stock: Billets and ingots for hot forging into complex shapes such as valve bodies and pump impellers for corrosive fluid handling.

Applications

The specialized properties of Alloy 404 (Monel 404) make it a preferred material in industries requiring corrosion resistance in reducing environments and precision manufacturing:

Chemical Processing:

Acid handling: Tubes and pipes for transporting sulfuric and hydrofluoric acids; plates for lining storage tanks and reaction vessels.

Pharmaceutical production: Bars machined into valves and fittings for high-purity chemical transfer; wire mesh for filtering corrosive solutions.

Laboratory equipment: Rods and sheets for fabricating beakers, reaction flasks, and analytical instrument components resistant to aggressive reagents.

Industrial and Scientific:

Thermocouples: Wire used as thermocouple extensions in chemical plants, where resistance to corrosive atmospheres is critical.

Electrical components: Ribbon and wire for connectors in chemical processing facilities, ensuring reliable performance in corrosive environments.

Precision machining: Bars and strips for manufacturing small, intricate parts like nozzles and metering valves in chemical dosing systems.

Specialized Environments:

Mining chemicals: Pipes and plates for handling sulfur-containing solutions in mineral processing; rods for agitators in leaching tanks.

Oil and gas refining: Components exposed to sour gas environments, such as valve trim and instrumentation parts machined from bar stock.

Wastewater treatment: Wire mesh screens for filtering corrosive effluents; sheets for lining treatment tanks.

Form-Specific Applications:

Wire: Fine mesh for chemical filtration, thermocouple wires, and small springs in laboratory equipment.

Tube/Pipe: Corrosive fluid transport in acid plants, pharmaceutical transfer lines, and analytical instrument tubing.

Plate/Sheet: Liners for chemical storage tanks, reaction vessel walls, and laboratory work surfaces.

Bar/Rod: Machined components like valve stems, pump shafts, and precision fittings for corrosive systems.

In summary, Alloy 404 (Monel 404) — available in forms from Bar and Wire to Plate and Forging Stock — delivers specialized corrosion resistance in reducing environments, excellent machinability, and precision formability. Its diverse product forms enable tailored solutions across chemical processing, pharmaceutical, and industrial sectors, establishing it as a critical material in specialized corrosive 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 2943 gallon liquid totes Special package is available on request.