Monel 400,UNS N0.4400, NCu30 Monel Alloy

The structure of Monel 400 alloy is a high-strength single-phase solid solution. It is a corrosion-resistant alloy.UNS N0.4400 is the most widely used.It has excellent comprehensive properties.It is generally has better corrosion resistance than nickel-copper. It is more resistant to media corrosion by reducing than pure nickel. It is more resistant to corrosion by oxidizing media than pure copper. Especially resistant to hydrochloric acid, it also has excellent corrosion resistance to hot concentrated alkali. Monel400 alloy has excellent corrosion resistance in fluorine gas, hydrochloric acid, sulfuric acid, hydrofluoric acid and their derivatives. It is also more corrosion resistant than copper-based alloys in seawater.

Physical Properties of Monel 400: 

Density8.83 g/cm3
Melting point1300-1390℃

Monel 400 is a deformable nickel-copper nickel-based alloy.It has good resistance to seawater corrosion and chemical corrosion, and strong resistance to chloride stress corrosion cracking. This alloy is one of the few alloys that can be used in fluoride. It has good resistance to oxide stress fission corrosion in hydrofluoric acid and fluorine gas medium, such as in seawater and saltwater environments.

It also has very good corrosion resistance in alkaline and saline solutions of medium concentration.In colder alkaline environments, the alloy is used in weak acids such as sulfur and hydrogen fluoride.

Acid medium: Monel 400 is corrosion resistant in sulfuric acid with a concentration of less than 85% is one of the very few important materials resistant to hydrofluoric acid.

Water corrosion: In most cases of water corrosion, Monel 400 alloy not only has excellent corrosion resistance, but also rarely finds pitting corrosion and stress corrosion. The corrosion rate is less than 0.025mm / a.

Chemical Composition of Monel 400:


%NickelCopperIron CarbonManganeseSiliconSulfur
Monel 400Small6328 – – – –


Big –342.50.320.5


High temperature corrosion: The maximum temperature of Monel 400 in air is generally around 600 ° C for continuous working. In high temperature steam, the corrosion rate is less than 0.026mm / a. Ammonia: Due to the high nickel content of Monel 400 alloy, it is resistant to corrosion under anhydrous ammonia and ammoniated conditions below 585 ° C.


Regarding welding materials and welding processes,it is recommended to use AWS A5.14 welding wire ERNiCu-7 or AWS A5.11 welding rod EniCrCu-7 for welding of MONEL400 alloy.

Application fields are sulfuric acid,hydrofluoric acid equipment, marine heat exchangers, desalination equipment, salt production equipment, marine and chemical processing equipment, propeller shafts and pumps, gasoline and water tanks.

EB Casting can supply Monel 400 castings, bars, forgings, plates,bolts.It can also be customized according to your needs。


Eternal Bliss Alloy Casting & Forging Co, Ltd.

Technical Dept.


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