Physical properties and chemical composition of Monel400 copper-nickel alloy

   Alloy 400 is a copper-nickel alloy with excellent corrosion resistance. It has good corrosion resistance in various media, good welding performance, high strength and medium strength. The alloy has been widely used in many occasions. It has excellent resistance to pitting and stress corrosion in salt water or sea water. Especially resistant to hydrofluoric acid and hydrochloric acid. It is widely used in chemical, petroleum and marine industries.

Monel400 similar grades

Germany: W.Nr.2.4360

United States: UNS NO4400

Monel400 Application Areas

• Power plant feedwater and steam generator oil pipes

• Manufacturing of pumps and valves

• Propeller shaft pump

• Industrial heat exchangers

• Splash jackets in offshore structures in seawater

• Extracting uranium isotopes from plants to produce nuclear fuel

• Sulfuric acid and hydrofluoric acid alkylation plants

• Brine boilers, seawater scrubbing in tanker inert gas systems

Monel400 Specifications

Rods, plates, tubes, wires, flanges, forgings, etc. are available for negotiation

Monel400 Technical Specifications

Forgings ASTM B564  

Bar ASTM B164

Plate/Strip ASTM B127

Seamless pipe ASTM B163/165

Monel400 corrosion resistance

• Excellent resistance to chloride ion stress corrosion cracking.

• Excellent resistance to neutral, alkaline and acidic salts, especially media containing oxidizing acid salts.

• Good resistance to sulfuric acid and hydrofluoric acid liquids.

This will lead to an increased corrosion rate.

• Exposure to fluorine, hydrofluoric acid, hydrofluoride or their derivatives.

Chemical composition of Monel400

Typical values(Weight %)

Monel400 mechanical properties (high quality bars)

Monel400 physical properties

Melting point: 1300-1350 ℃

Density: 8.8 g/cm3

Hardness: ≥331 (HBS)

Monel400 Processing

Thermal processing

Annealing temperature should be controlled at 700-900 ℃, and rapid air cooling is recommended to obtain the best corrosion resistance. Time and temperature will directly affect the final grain size, and annealing parameters must be carefully formulated.

Cold Working

Intermediate annealing should be performed during cold working. It has a high work hardening rate.

The cold forming deformation is higher than 5%, and it must be used after stress relief or annealing.

Monel400 welding process

Welding can be done by argon arc welding, plasma arc, gas shielded welding or manual arc welding. Pulse arc welding is recommended first. It is best to perform surface treatment after welding.