The structure of Monel 400 (UNS N04400, NCu30) alloy is a high-strength single-phase solid solution. It is a corrosion-resistant alloy with the largest dosage, the most widely used and excellent comprehensive properties. This alloy has excellent corrosion resistance in hydrofluoric acid and fluorine gas media, and also has excellent corrosion resistance against hot concentrated alkali liquid. It is also resistant to corrosion from neutral solutions, water, seawater, atmosphere, organic compounds, etc. An important feature of this alloy is that it generally does not produce stress corrosion cracking and has good cutting performance.

Monel 400 alloy is a copper-nickel alloy with excellent corrosion resistance in various media, good welding performance, high strength and moderate strength. This alloy has been widely used in many occasions. In salt water or Seawater has excellent resistance to pitting corrosion and stress corrosion. It is especially resistant to hydrofluoric acid and hydrochloric acid. It is widely used in chemical, petroleum, and marine industries. It is suitable for various corrosive environments, resistant to chloride ion stress corrosion cracking, and has good strength and toughness within a certain temperature range.