Technical Specifications — Alloy 400 (UNS N04400)
UNS No.
N04400 – BS No. BS3074 NA13
Chemical Composition (%)
Ni: ≥ 63.0
Cu: 28.0 – 34.0
Fe: ≤ 2.5
Mn: ≤ 2.0
C: ≤ 0.30
Si: ≤ 0.50
S: ≤ 0.024
ASTM Specification
B163, B165, B828
ASME Specification
SB163, SB165, SB828
Typical Applications
Marine engineering, chemical processing, hydrocarbon processing, heat exchangers, alkylation units, and seawater service equipment
Temper
Annealed / Stress Relieved
Properties and Metrics
| Property |
Metric |
English |
| Density |
8.80 g/cm³ |
0.318 lb/in³ |
| Tensile Strength – Annealed (min.) |
483 MPa |
70 ksi |
| Tensile Strength – Stress Relieved (min.) |
586 MPa |
85 ksi |
| Yield Strength – Annealed (min.) |
125 MPa |
28 ksi |
| Yield Strength – Stress Relieved (min.) |
379 MPa |
55 ksi |
| CTE, Linear |
14.2 µm/m·°C @ 100°C |
7.7 ×10⁻⁶ in/in/°F @ 200°F |
| Specific Heat Capacity |
445 J/kg·°C @ 100°C |
0.105 BTU/lb·°F @ 200°F |
| Thermal Conductivity |
24.0 W/m·°C @ 100°C |
167 BTU-in/h/ft²/°F @ 200°F |
| Melting Point |
1300 – 1350°C |
2370 – 2460°F |
* The values shown above are typical reference data only and should not be used for design or engineering purposes.
FAQ
What is Alloy 400 (N04400)?
Alloy 400 (UNS N04400) is a nickel-copper alloy containing approximately 63% nickel and 28–34% copper. It is known for excellent corrosion resistance in seawater, acids, and alkaline environments, along with good mechanical strength and toughness across a wide temperature range.
What is N04400 used for?
N04400 tubes are widely used in marine engineering, chemical processing, oil & gas, and heat exchanger applications. Typical uses include seawater piping, condensers, evaporators, alkylation units, and equipment handling corrosive chemicals.
Is Alloy 400 resistant to seawater corrosion?
Yes. Alloy 400 offers excellent resistance to seawater and brine, including resistance to pitting, stress corrosion cracking, and erosion. This makes it suitable for marine heat exchangers, seawater cooling systems, and offshore applications.
What is the difference between Monel 400 and N04400?
Monel 400 is the common trade name, while N04400 is the UNS material designation for the same nickel-copper alloy. Both refer to the same material with identical chemical composition and performance characteristics.
Can Alloy 400 tubes be welded and fabricated?
Yes. Alloy 400 has good ductility and can be welded, expanded, bent, and fabricated using conventional methods. This makes it suitable for U-bend tubes, heat exchangers, and complex piping systems.
What temperature range can N04400 handle?
Alloy 400 maintains good mechanical properties from sub-zero temperatures up to approximately 550°C. It also performs well in cryogenic applications due to its toughness and resistance to thermal stress.
Which industries use Alloy 400 tubes?
Common industries include marine engineering, chemical processing, oil & gas, desalination, power generation, and offshore platforms. These sectors use Alloy 400 for its strength and corrosion resistance in aggressive environments.
What standards apply to N04400 tubes?
Alloy 400 tubes are typically manufactured according to ASTM B163, ASTM B165, ASTM B828 and corresponding ASME SB163, SB165, SB828 specifications.
