What Monel 400 is
Monel 400 is a solid-solution nickel-copper alloy, about 65% nickel and 32% copper with iron and manganese. It is stronger and tougher than the copper-nickel alloys, resists seawater erosion at velocities where they wear, and is one of very few engineering alloys that tolerate hydrofluoric acid. It is also immune to chloride stress corrosion cracking and highly resistant to sulfide stress cracking.
Standards we supply to
- ASTM B163 / ASME SB-163, condenser and heat exchanger tube
- ASTM B165 / ASME SB-165, seamless pipe and tube
- ASTM B725 and B730 welded on request
- QQ-N-281 and military specifications on request
Chemical composition
| Element | Requirement |
|---|---|
| Nickel (plus cobalt) | 63.0% min |
| Copper | 28.0 to 34.0% |
| Iron | 2.5% max |
| Manganese | 2.0% max |
| Carbon | 0.3% max |
| Silicon | 0.5% max |
Typical mechanical properties, annealed
| Property | Value |
|---|---|
| Tensile strength | 70,000 psi min (480 MPa) |
| Yield strength | 28,000 psi min (195 MPa) |
| Elongation in 2" | 35% min |
Where it is used
- Naval seawater systems, heat exchangers, and pump and valve trim.
- HF alkylation units in refineries: piping, exchangers, and reboilers.
- Sour gas production tubing and downhole components.
- Salt production and brine heaters.
- Chemical process exchangers in fluoride, sulfuric acid, and alkaline service.
Monel 400 or 405
Monel 405 is the free-machining version, with sulfur added for machinability. It is used for screw-machine parts and fittings, not for tube. See the Monel 405 page.
OD, wall, length, quantity, ASTM B163 (heat exchanger) or B165 (pipe and tube), temper, and the service. For sour service state the NACE MR0175 requirement; for HF alkylation state the licensor specification.