Premium nickel-copper alloy with exceptional corrosion resistance in seawater, acids, and alkaline environments. The trusted choice for Australian marine and offshore applications.
Monel 400 offers unmatched performance in corrosive environments where stainless steel fails, making it essential for Australian marine and chemical processing industries.
Superior resistance to seawater corrosion and biofouling. Maintains integrity in marine environments where stainless steel pits and corrodes.
Excellent resistance to hydrofluoric acid, sulfuric acid (non-oxidizing), and alkaline solutions. Ideal for chemical processing applications.
Maintains strength and ductility from cryogenic temperatures (-200°C) to elevated temperatures (400°C). Versatile for diverse applications.
Non-magnetic properties essential for compass housings, marine instruments, and applications requiring electromagnetic transparency.
| Element | Composition % | Purpose |
|---|---|---|
| Nickel (Ni) | 63.0 min | Primary base metal, corrosion resistance |
| Copper (Cu) | 28.0 - 34.0 | Enhanced resistance to reducing acids and seawater |
| Iron (Fe) | 2.5 max | Strength enhancement, cost reduction |
| Manganese (Mn) | 2.0 max | Deoxidizer, sulfur control |
| Carbon (C) | 0.3 max | Controlled as impurity |
| Silicon (Si) | 0.5 max | Deoxidizer |
| Sulfur (S) | 0.024 max | Controlled as impurity |
Note: Monel 400 is essentially a binary nickel-copper alloy with excellent solid solution strengthening and corrosion resistance across the entire nickel-copper composition range.
| Property | Annealed |
|---|---|
| Tensile Strength | 520-690 MPa |
| Yield Strength (0.2%) | 240-345 MPa |
| Elongation | 35-50% |
| Hardness | 110-150 HB |
| Impact Strength | ≥ 200 J |
| Physical Property | Value |
|---|---|
| Density | 8.8 g/cm³ |
| Elastic Modulus | 179 GPa |
| Thermal Conductivity (20°C) | 21.8 W/m·K |
| Thermal Expansion (20-100°C) | 13.9 × 10⁻⁶ /°C |
| Electrical Resistivity | 0.547 μΩ·m |
Monel 400 is significantly more challenging to machine than stainless steel due to high work hardening rate, low thermal conductivity, and abrasive nature. Proper tooling, parameters, and technique are essential for successful machining.
Rapid work hardening under cutting forces requires continuous cutting action with sharp tools and consistent feeds.
Heat concentrates at cutting edge rather than dispersing. Aggressive coolant application essential to prevent tool failure.
Produces long, stringy chips that can tangle. Good chip evacuation and chip breaker geometry critical.
Abrasive nature causes rapid tool wear. Carbide or ceramic tooling with coatings strongly recommended.
| Operation | Speed | Feed |
|---|---|---|
| Turning (HSS) | 12-18 m/min | 0.10-0.25 mm/rev |
| Turning (Carbide) | 30-45 m/min | 0.15-0.35 mm/rev |
| Milling (HSS) | 8-12 m/min | 0.05-0.15 mm/tooth |
| Milling (Carbide) | 25-40 m/min | 0.10-0.25 mm/tooth |
| Drilling (HSS) | 6-10 m/min | 0.05-0.12 mm/rev |
| Drilling (Carbide) | 18-30 m/min | 0.08-0.18 mm/rev |
Critical: Speeds are 50-70% slower than for stainless steel. Never allow tool to dwell or rub—this creates work-hardened layers impossible to cut.
Fedele Autocore has extensive experience machining Monel 400 and other difficult nickel alloys for Australian marine, chemical processing, and oil & gas industries. Our specialized tooling and expertise ensure quality results with this challenging material.
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