Monel 400

Monel 400 2.4360 Nickel Alloy is a Nickel-Copper alloy that is resistant to seawater and steam at high temperature as well as to salt and caustic solutions. Alloy 400 is a solid solution alloy that can only be hardened bycold working. This nickel alloy exhibits characteristics like good corrosion resistance, good weldability and high strength. A low corrosion rate in rapidly flowing brackish or seawater combined with excellent resistance to stress-corrosion cracking in most freshwater, and its resistance to variety of corrosive condition led to its wide use in marine application and other non-oxidizing chloride solutions.

Alloy 400 2.4360 Nickel Alloy is particularly resistant to hydrochloric acid and hydrofluoric acid when they are de-aerated. As would be expected from its high copper content, alloy 400 is rapidly attacked by nitric acid andammonia systems. Monel 400 has great mechanical properties at subzero temperatures, can be used in temperatures up to 1000° F, and its melting point is 2370-2460° F. However, alloy 400 is low in strength in the annealed condition so, a variety of tempers may be used to increase the strength.

Alloy 400 2.4360 Nickel Alloy is a nickel-copper alloy with excellent corrosion resistance in a wide variety of media. The alloy is characterized by good general corrosion resistance, good weldability and moderate to high strength. The alloy has been used in a variety of applications. It has excellent resistance to rapidly flowing brackish water or seawater. It is particularly resistant to hydrochloric acid and hydrofluoric acids when they are de-aerated. The alloy is slightly magnetic at room temperature. The alloy is widely used in the chemical, oil and marine industries.

Alloy 400 2.4360 Nickel Alloy is widely used in many fields, especially marine and chemical processing. Typical applications are valves and pumps; pump and propeller shafts; marine fixtures and fasteners; electrical and electronic components;springs; chemical processing equipment; gasoline and fresh water tanks; crude petroleum stills, process vessels and piping;boiler feed water heaters and other heat exchangers; and deaerating heaters.

Monel 400 Chemical composition

Monel 400 Characteristics

• Corrosion resistance in an extensive range of marine and chemical environments. From pure water to nonoxidizing mineral acids, salts and alkalis.
• This alloy is more resistant to nickel under reducing conditions and more resistant than copper under oxidizing conditions, it does show however better resistance to reducing media than oxidizing.
• Good mechanical properties from subzero temperatures up to about 480C.
• Good resistance to sulfuric and hydrofluoric acid. Aeration however will result in increased corrosion rates. May be used to handle hydrochloric acid, but the presence of oxidizing salts will greatly accelerate corrosive attack.
• Resistance to neutral, alkaline and acid salts is shown, but poor resistance is found with oxidizing acid salts such as ferric chloride.
• Excellent resistance to chloride ion stress corrosion cracking.

Monel 400 Applications

• Feed water and steam generator tubing.
• Brine heaters, sea water scrubbers in tanker inert gas systems.
• Sulfuric acid and hydrofluoric acid alkylation plants.
• Pickling bat heating coils.
• Heat exchanger in a variety of industries.
• Transfer piping from oil refinery crude columns.
• Plant for the refining of uranium and isotope separation in the production of nuclear fuel.
• Pumps and valves used in the manufacture of perchlorethylene, chlorinated plastics.
• Monoethanolamine (MEA) reboiling tube.
• Cladding for the upper areas of oil refinery crude columns.
• Propeller and pump shafts.

Monel 400 Specifications

UNS N04400
BS 3072 – 3076 (NA13)
ASTM B 127, B 163 – B 165,
B 366, B 564, B 725, B 730,
B 751, B 775, B 829
ASME SB-127, SB-163 – SB-165,
SB-366, SB-564, SB-725,
SB-730, SB-751, SB-775,
SB-829
AECMA Pr EN 2305
SAE AMS 4544, 4574,
4675, 4730, 4731, 7233
DIN 17743, 17750 – 17754
Werkstoff Nr. 2.4360,
2.4361
VdTÜV 263
QQ-N 281
NACE MR-01-75

Monel 400 Corrosion Resistant

Alloy 400 is virtually immune to chloride ion stress corrosion cracking in typical environments. Generally, its corrosion resistance is very good in reducing environments, but poor in oxidizing conditions. It is not useful in oxidizing acids, such asnitric acid and nitrous. Nevertheless, it is resistant to most alkalis, salts, waters, food products, organic substances and atmospheric conditions at normal and elevated temperatures.
This nickel alloy is attacked in sulfur-bearing gases above approximately 700° F and molten sulfur attacks the alloy at temperatures over approximately 500° F.

Monel 400 offers about the same corrosion resistance as nickel but with higher maximum working pressure and temperatures and at a lower cost due to its superior ability to be machined.

Monel 400 Fabrication

Alloy 400 can easily be welded by gas-tungsten arc, gas metal arc or shielded metal arc processes using appropriate filler metals. There is no need for post weld heat treatment, however, thorough cleaning after welding is critical for optimum corrosion resistance, otherwise there is the risk of contamination and embrittlement.
Finished fabrications can be produced to a wide range of mechanical properties when proper control of the amount of hot or cold working and the selection of appropriate thermal treatments is done.

Like most other nickel alloys, Monel 400 is typically tough to machine and will work harden. However, excellent results can e obtained if you make the correct choices for tooling and machining.

Monel 400 ASTM Specifications

Monel 400 Mechanical Properties

Typical room temperature Tensile Properties of Annealed Material

*The ranges shown are composites for various product sizes and therefore are not suitable for specification purposes. Hardness values are suitable for specification purposes provided tensile properties are not also specified.

Incoloy: Incoloy 800 | Incoloy 800H | Incoloy 800HT | Incoloy 825 | Incoloy 901 | Incoloy 925 | Incoloy 926
Inconel: Inconel 600 | Inconel 601 | Inconel 625 | Inconel 706 | Inconel 718 | Inconel X-750
Hastelloy: Hastelloy B | Hastelloy B-2 | Hastelloy B-3 | Hastelloy C-4 | Hastelloy C-22 | Hastelloy C-276 | Hastelloy X|Hastelloy G | Hastelloy G3
Nimonic: Nimonic 75 | Nimonic 80A | Nimonic 90
Monel: Alloy 20 | Nickel 200 | Nickel 201 | Monel 400 | Monel 401 | Monel R 405 | Monel K 500
Other: A286 | 17-4PH