Monel 400 is a nickel-copper alloy known for its excellent corrosion resistance, especially in marine and chemical environments. Its nominal chemical composition is:
| Element | Content (%) |
|---|---|
| Nickel (Ni) | ≥ 63.0 |
| Copper (Cu) | 28.0 – 34.0 |
| Iron (Fe) | ≤ 2.5 |
| Manganese (Mn) | ≤ 2.0 |
| Carbon (C) | ≤ 0.30 |
| Silicon (Si) | ≤ 0.50 |
| Sulfur (S) | ≤ 0.024 |
Monel 400 is designated as UNS N04400 and commonly conforms to standards such as ASTM B164 (bars), ASTM B127 (plates), ASTM B165 (pipes and tubes).
✅ Mechanical Properties (Typical at Room Temperature)
| Property | Value |
|---|---|
| Tensile Strength | 70 – 85 ksi (485 – 586 MPa) |
| Yield Strength (0.2%) | ≥ 25 – 35 ksi (172 – 241 MPa) |
| Elongation | ≥ 30% |
| Hardness | Approx. 65 HRB (annealed) |
| Density | 8.80 g/cm³ |
| Melting Range | 1300–1350 °C (2370–2460 °F) |
Note: Properties may vary slightly depending on product form and heat treatment.
🔧 Key Features
Excellent resistance to seawater and salt solutions
High strength and toughness over a wide temperature range
Good weldability
Resists stress corrosion cracking in most freshwaters
🛠️ Typical Applications
Marine Engineering: Pump and valve components, shafts, seawater systems
Chemical Processing: Heat exchangers, vessels, piping systems
Oil and Gas: Sour gas service, refinery equipment
Aerospace: Fuel and hydraulic lines
Power Generation: Boiler feedwater heaters and condensers
