UNS N04400 Heat Exchanger Seamless Tube Detailed Introduction
UNS N04400 Heat Exchanger Seamless Tube Detailed Introduction
UNS N04400, commonly known as Monel 400, is a nickel-copper alloy widely used in the manufacture of seamless heat exchanger tubing due to its high strength and excellent corrosion resistance over a wide temperature range. It is particularly effective in marine and chemical processing environments where resistance to corrosive media is critical.
What is the maximum operating temperature for Monel 400?
Monel 400 exhibits excellent mechanical properties in subzero temperatures and can be used at temperatures up to 1000°F. Its melting point is 2370-2460°F. However, 400 alloy has low strength in the annealed state, so various tempering processes can be used to increase its strength.
ASTM B163 UNS N04400 UNS N04400 Heat Exchanger Seamless Tube Equivalent Grades
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN |
|---|---|---|---|---|---|---|---|
| Monel 400 | 2.4360 | N04400 | NW 4400 | NA 13 | МНЖМц 28-2,5-1,5 | NU-30M | NiCu30Fe |
ASTM B163 UNS N04400 Monel 400 Nickel Alloy Tube Chemical Composition %
|
Grade |
C |
Mn |
Si |
S |
Cu |
Fe |
Ni |
|---|---|---|---|---|---|---|---|
|
Monel 400 |
0.30 max | 2.00 max | 0.50 max | 0.024 max | 28.00 – 34.00 | 2.50 max | 63.00 min |
ASTM B163 UNS N04400 Monel 400 Nickel Alloy Tube Mechanical properties
| Grade | Density | Melting Point |
Tensile Strength |
Yield Strength |
Elongation |
| Monel 400 | 8.8g/cm³ |
1350℃ (2460℉) |
Psi-80000 MPa-550 |
Psi-35000 MPa-240 |
40% |
Corrosion Resistance
The primary advantage of Monel 400 in heat exchanger applications lies in its exceptional corrosion resistance.
Seawater and brackish water: Excellent resistance to corrosion, pitting, and stress corrosion cracking, even at high temperatures and high velocities.
Acid Resistance: Excellent resistance to degassed hydrofluoric and hydrochloric acids, and withstands sulfuric acid concentrations up to 85%.
Alkali Resistance: Excellent resistance to alkalis and alkaline salt solutions.
High-Temperature Steam Resistance: Corrosion rates are very low in high-temperature steam.
Oxidizing Media Resistance: Monel 400 has limited corrosion resistance compared to reducing media. It is not suitable for use with highly oxidizing acids such as nitric and nitrous acids.
Manufacturing and Specifications
Seamless UNS N04400 pipe is typically produced to ASTM B163 for use in condensers and heat exchangers.
Manufacturing Process: Pipe can be manufactured using either hot-rolled or cold-rolled processes. Hot working temperatures range from 650°C to 1175°C.
Condition: Tubes are typically supplied in the annealed or stress-relieved condition. Cold working and stress relieving can improve mechanical properties.
Shapes: Available in straight or U-bend configurations.
Surface Treatment: A variety of surface treatments are available, such as polished, annealed pickled (AP), or bright annealed (BA).
Typical Heat Exchanger Applications
The combination of high strength, high toughness, and excellent corrosion resistance makes UNS N04400 seamless tubing an ideal choice for demanding heat exchanger applications.
Marine Systems: Heat exchangers and condensers for seawater applications.
Chemical Processing: Equipment handling corrosive chemicals, particularly those involving hydrofluoric and sulfuric acids.
Power Generation: Boiler feedwater heaters and steam generators in nuclear and conventional power plants.
Oil and Gas Refineries: Heat exchanger piping in crude oil stills.
Desalination Plants: Brine heaters and evaporator bodies.
Gnee Steel specializes in the production and sale of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. Gnee Steel's products are widely used in aerospace, chemical, electric power, automotive, and nuclear energy applications. We also offer customized alloy solutions tailored to customer needs. For alloy pricing inquiries or customized alloy solutions, please contact us for a quote at ss@gneesteel.com.
