MONEL® 400 is a nickel-copper alloy with high strength and excellent corrosion resistance in a variety of media, including seawater, hydrofluoric acid, sulfuric acid and alkalis. The alloy is used in marine engineering, the chemical process industry and hydrocarbon processing – for example in valves, pumps, shafts, fittings, fasteners and heat exchangers. Recommended filler material for welding is MONEL® 60 (wire) or MONEL® 190 (electrodes).
HARALD PIHL stocks, among others, MONEL® 400 in the following forms and standards:
Coil (coil/strip) - ASTMB127
Sheet/Plate (plate) - ASTMB127
Round bar (round bar) - ASTMB164
Tube/pipe (pipe) - ASTM B165
We also have the ability to produce other dimensions, forms and specifications upon request. Please contact us and we will help you find the right material for your needs.
General material description:
Type: Nickel–copper alloy (approx. 67% Ni, 30% Cu)
Structure: Single-phase FCC structure (austenitic)
Developed for: Demanding environments where corrosion, cavitation and stress cracking occur
Alternative names: MONEL® 400, Alloy 400, UNS N04400, Werkstoffnr 2.4360, ASTM B127, B164, B165
Key benefits:
Excellent corrosion resistance in seawater, acids, alkalis and hydrofluoric acid
Good resistance to stress corrosion cracking, cavitation and cracking
Maintains toughness and strength at both high and low temperatures
Good weldability and formability
Disadvantages / limitations:
Lower tensile strength than some other high-alloy materials
Not optimal for strongly oxidizing acids such as nitric acid
Limited oxidation resistance at very high temperatures
Not hardenable by heat - only cold working increases strength
Applications by industry and value:
Marine technology: Propeller shafts, valves, pump parts - seawater resistance
Chemical industry: Heat exchangers, tanks, pipes - resistance to aggressive media
Petrochemistry: Desulfurization systems, hydrocarbon processes - high toughness and chemical resistance
Paper & pulp: Process equipment in caustic environments
Aviation & defense: Fasteners, components - strength in corrosive environments
General corrosion description:
Excellent resistance to corrosion in seawater, hydrofluoric acid, alkalis and organic acids
Good resistance to cavitation and stress corrosion
Not suitable for strongly oxidizing acids such as concentrated nitric acid
Corrosion environments where the material performs well:
Seawater, brines, hydrofluoric acid, dilute sulfuric acid
Alkaline environments and organic acids (e.g. acetic acid)
Wet gas and slightly reducing environments
Corrosion environments where the material should be avoided:
Concentrated nitric acid
Oxidizing acids with high chloride levels
Environments with strong oxidation at high temperatures
Technical material properties:
Property (Typical value)
Yield strength (0.2%): 170–275 MPa
Tensile strength: 480–620 MPa
Elongation at break: 35–45%
Density: 8.8 g/cm³
Modulus of elasticity: 179 GPa
Thermal conductivity: ~21 W/m·K
Operating temperature: Up to 550°C
Weldability: Good, recommended filler material required
Machinability: Moderate, requires cooling and stable tools