UNS N04400 Monel 400 Nickel Copper Alloy Strip Used for Corrosion
Resistance
Monel 400(UNS N04400/2.4360) is a nickel-copper alloy with high
strength and excellent resistance to a range of media including
seawater, dilute hydrofluoric and sulfuric acids, and alkalies.
Monel 400 containing about 30–33% copper in a nickel matrix has
many similar characteristics of commercially pure nickel, while
improving upon many others. Addition of some iron significantly
improves the resistance to cavitation and erosion in condenser tube
applications. The main uses of Monel 400 are under conditions of
high flow velocity and erosion as in propeller shafts, propellers,
pump-impeller blades, casings, condenser tubes, and heat exchanger
tubes. Corrosion rate in moving seawater is generally less than
0.025 mm/year. The alloy can pit in stagnant seawater, however, the
rate of attack is considerably less than in commercially pure alloy
200. Due to its high nickel content (approx. 65%) the alloy is
generally immune to chloride stress corrosion cracking. The general
corrosion resistance of Monel 400 in nonoxidizing mineral acids is better compared to nickel.
However, it suffers from the same weakness of exhibiting very poor
corrosion resistance to oxidizing media such as nitric acid, ferric
chloride, cupric chloride, wet chlorine, chromic acid, sulfur
dioxide, or ammonia. In unaerated dilute hydrochloric and sulfuric
acid solution the alloy has useful resistance up to concentrations
of 15% at room temperature and up to 2% at somewhat higher
temperature, not exceeding 50°C. Due to this specific
characteristic, Monel 400 produced by NiWire is also used in processes where chlorinated solvents may form
hydrochloric acid due to hydrolysis, which would cause failure in
standard stainless steel.
Monel 400 possesses good corrosion resistance at ambient
temperatures to all HF concentration in the absence of air. Aerated
solutions and higher temperature increase the corrosion rate. The
alloy is susceptible to stress corrosion cracking in moist aerated
hydrofluoric or hydrofluorosilic acid vapor. This can be minimized
by deaeration of the environments or by stress relieving anneal of
the component in question.
Typical applications are valve and pump parts, propeller shafts,
marine fixtures and fasteners, electronic components, chemical
processing equipment, gasoline and freshwater tanks, petroleum
processing equipment, boiler feedwater heaters and other heat
exchangers
Chemical Composition
| Grade | Ni% | Cu% | Fe% | C% | Mn% | C% | Si% | S% |
| Monel 400 | Min 63 | 28-34 | Max 2.5 | Max 0.3 | Max 2.0 | Max 0.05 | Max 0.5 | Max 0.024 |
Specifications
| Grade | UNS | Werkstoff Nr. |
| Monel 400 | N04400 | 2.4360 |
Physical Properties
| Grade | Density | Melting Point |
| Monel 400 | 8.83 g/cm3 | 1300°C-1390°C |
Mechanical Properties
| Alloy | Tensile Strength | Yield Strength | Elongation |
| Monel 400 | 480 N/mm² | 170 N/mm² | 35% |
Our Production Standard
| Standard | Bar | Forging | Pipe/Tube | Sheet/Strip | Wire | Fittings |
| ASTM | ASTM B164 | ASTM B564 | ASTM B165/730 | ASTM B127 | ASTM B164 | ASTM B366 |
Size Range
Monel 400 wire, bar, rod, strip, forging, plate, sheet, tube,
fastener and other standard forms are available.
