MONEL® alloy 400


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 ASTMMin.Max.Min.Max.Min.Max.
ConstantsMelting Range,℃1300-1350
MechanicalTensile Strength,ksi80
Yield Strength (0.2% Offset),ksi35
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.
CharactersMonel 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

Technical Data Sheet

Alloy 400 (UNS N04400) is a nickel-copper alloy with high strength (comparable to structural steel) and toughness. Alloy 400 also has excellent corrosion resistance in a range of media including seawater, hydrofluoric acid, sulphuric acid and alkalis. Used for marine engineering, chemical, hydrocarbon processing equipment, and heat exchangers.

Chemical Composition Limits
Weight %CSNi+CoFeMnSiCu
Nickel 4000.30 max0.024 max63.0 max2.50 max2.0 max0.50 max28-34

Typical Mechanical Properties

MaterialForm and ConditionTensile Strength MPaYield Strength (0.2% Offset) MPaElongation (%)Hardness Rockwell B
Alloy 400Annealed Rod and Bar517-620172-34560-3560-80
Alloy 400Hot Rolled Plate Annealed482-586193-34550-3560-76
Alloy 400Sheet Annealed482-586207-31045-3565-80
Alloy 400Tube Cold drawn Annealed Seamless482-586172-31050-3575 max

Alloy 400 (UNS N04400) is available in Bar (Round), Tube, Flat Bar, Wire, Billet, Sheet, Plate, Pipe, Forgings.


BarASTM B 164, QQ N 281, DIN 17752, AMS 4675
SheetASTM B 127, QQ N 281, BS3072NA13, AMS 4544, DIN 17750
PlateASTM B 127, QQN 281, BS3072NA13, AMS 4544, DIN 17750
StripBS3073NA13, ASTM B127, AMS 4544, DIN 17750
PipeASTM B 185
TubeASTM B165, AMS 4574, AMS 4575
ForgingASTM B564, DIN 17752, AMS 4675
OtherW.Nr 2.4360, UNS N04400, NACE MR-01-75, Wire AMS 4730 Monel 400 (tradename), ISO 15156