Monel 400 alloy

Monel 400 alloy (UNS N04400 or McU-28-1.5-1.8 or Ni68Cu28Fe) is a nickel base alloy material with good corrosion resistance in seawater, chemical solvents, amiothiochlorine, hydrogen chloride, various acidic media such as sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid, organic acids, alkaline media, salts and molten salts.

Chinese name: Alloy 400

Thermal conductivity: 21.8 W/m K

Melting point: 1300-1350 ° C

Magnetic sex: 200H(At 70 F)

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Monel 400 (UNS N04400)

SummaryA nickel-copper alloy with high strength and excellent corrosion resistance in a range of media including sea water, hydrofluoric acid,sulfuric acid, and alkalies. Used for marine engineering, chemical and hydrocarbon processing equipment, valves, pumps, shafts, fittings,fasteners, and heat exchangers.
StandardPipe, tube, sheet, strip, plate, round bar, flat bar, forging stock, hexagon and wire.
Product Forms

Chemical composition (wt.-%) according to ASTM





Melting Range,℃1300-1350




Tensile Strength,ksi80


Yield Strength (0.2% Offset),ksi35

Monel 400
Monel 400
MicrostructureMonel 400 is a solid-solution binary alloy. As nickel and copper are mutually soluble in all proportions, it is a single-phase alloy. It has a face-centered cubic lattice structure with a lattice parameter of 3.534 A.


Monel 400,with an excellent combination property,is a corrosion resistant alloy in a wide range of use and applications.It has an excellent corrossion resistance in the media of hydrofluoric acid and fluorine and also has a good corrossion resistance to hot strong alkali liquor.

Besides it also resistant to corrossion in the neutral solution,water,sea water,air,organic compound etc..One important character of the alloy is that the stress corrossion cracking normorlly doesn’t occur and it has a good machinability.

Corrosion Resistance

Monel 400 exhibits resistance to corrosion by many reducing media. It is also generally more resistant to attack by oxidizing media than higher copper alloys. This
versatility makes alloy 400 suitable for service in a variety of
Alloy 400 is widely used in marine applications. While alloy 400 products exhibit very low corrosion rates in flowing seawater, stagnant conditions have been shown to induce crevice and pitting corrosion. Alloy 400 is also resistant to stress corrosion cracking and pitting in most fresh and industrial waters.
Monel 400 offers exceptional resistance to hydrofluoric acid in all concentrations up to the boiling point. It is perhaps the most resistant of all commonly used
engineering alloys. Alloy 400 is also resistant to many
forms of sulfuric and hydrochloric acids under reducing


Monel 400 is a material in a variety of applications,and is applied in many industrial areas.
1. feed-water and steam generator tubing in power plants
2. brine heaters and evaporator bodies in seawater desalination plants
3. pumps and valves used in the manufacture of chlorinated hydrocarbons
4 cladding for crude oil distillation columns
5. splash-zone sheathing in offshore structures
6. plants for uranium refining and isotope separation
in the production of nuclear fuel
7. propeller and pump shafts for seawater service