Alloy SteelBar/Rod
Description (English)
Q1: What is UNS N04400 / Alloy 400? UNS N04400 — known commercially as Monel 400 or Alloy 400 — is a nickel-copper solid-solution alloy with a minimum of 63% nickel and 28–34% copper. It cannot be hardened by heat treatment; strength comes from cold work. Its combination of high strength, toughness from cryogenic temperatures to about 480°C, and outstanding resistance to seawater, hydrofluoric acid and caustic solutions has made it the reference material for marine and chemical process equipment since the 1920s.
Size Range
- Bar diameter: 6–305 mm (hot worked / forged); cold drawn ≤ 101.6 mm
- Tube OD:6–219 mm (1/4"–8"), wall 0.5–20 mm
- Condition:Annealed / hot-worked / cold-worked (as-worked or stress-relieved)
- Length:Bar 1,000–6,000 mm; tube random 5.8–6.1 m or cut-to-length up to 12 m
- Surface:Pickled, bright annealed, turned / peeled, polished on request
Grade Specification
| System | Value |
|---|---|
| Grade | UNS N04400 (Alloy 400 / Monel 400) |
| W.Nr / EN | 2.4360 (2.4361 low-carbon) / NiCu30Fe |
Chemical Composition
| Element | Value |
|---|---|
| Nickel (Ni), incl. Cobalt | 63.0 min |
| Copper (Cu) | 28.0–34.0 |
| Iron (Fe) | ≤ 2.50 |
| Manganese (Mn) | ≤ 2.00 |
| Carbon (C) | ≤ 0.30 |
| Silicon (Si) | ≤ 0.50 |
| Sulfur (S) | ≤ 0.024 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength min. | 552 MPa (80 ksi) |
| Yield Strength 0.2% min. | 276 MPa (40 ksi) |
| Elongation min. | 30% |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | - | 8.80 g/cm³ (0.318 lb/in³) |
| Melting Range | - | 1,300–1,350°C (2,370–2,460°F) |
| Modulus of Elasticity | - | 179 GPa (26.0 × 10⁶ psi) |
| Thermal Conductivity (20°C) | - | 21.8 W/(m·K) |
| Specific Heat | - | 427 J/(kg·K) |
| Electrical Resistivity | - | 0.511 µΩ·m (51.1 µΩ·cm) |
| CTE, 20–100°C | - | 13.9 × 10⁻⁶ /K |
| CTE, 20–200°C | - | 15.5 × 10⁻⁶ /K |
| CTE, 20–425°C | - | 16.0 × 10⁻⁶ /K |
| Curie Temperature | - | 20–50°C |
| Magnetic Behaviour | - | Mildly magnetic at room temperature; essentially non-magnetic above the Curie temperature |
| Max Service Temperature | - | ≈ 480°C continuous, up to 538°C short-term |
Applications
- Oil & Gas:Sour gas tubing, pump shafts, valve trim, HF alkylation unit piping
- Marine & Offshore:Seawater piping, propeller shafts, pump and valve parts, marine fasteners
- Chemical Processing:HF and sulfuric acid lines, caustic loops, heat exchanger tubing, vessels
- Power & Desalination:Boiler feedwater heaters, MSF / MED desalination tubing and pipework
- Petrochemical:Crude distillation trays, chlorine / chlor-alkali equipment
- Nuclear:Uranium refining and isotope separation equipment (B513 supplementary NDT requirements)
- Instrumentation:Trace-heating tubing, instrumentation and impulse lines in chloride-rich environments