What material is Alloy 400 made of?
a brief introdction:
Alloy 400 is an alloy material with high strength and toughness, as well as a wide range of corrosion resistance. It is suitable for parts working in corrosive media such as seawater, hydrofluoric acid, sulfuric acid, alkali, etc. It has a wide range of applications in the fields of shipbuilding and chemical industry. Applications such as pumps, valves, shafts, fittings, fasteners, heat exchangers, etc.
Details description:
Alloy 400 alloy
Alloy 400 corresponding grades: UNS N04400, 2.4360, NiCu30Fe, NW4400, NA12, Ni68Cu28Fe, Monel400
Introduction to Alloy 400: Alloy 400 alloy is a corrosion-resistant alloy with the largest consumption, the most wide range of uses, and excellent comprehensive properties. The alloy has good corrosion resistance in hydrofluoric acid and fluorine gas media, as well as in hot concentrated alkali solutions. It also has corrosion resistance to neutral solutions, water, seawater, atmosphere and organic matter. An important feature of this alloy is that it does not produce stress corrosion cracking and has good cutting performance.
The chemical composition of Alloy 400 alloy is mainly 30% copper and 65% nickel, with a small amount of iron (1%-2%). The microstructure of Alloy 400 alloy is a typical single-phase austenite structure. Since nickel and copper are soluble in each other in any proportion, there is no intermetallic phase precipitation. The microstructure of the alloy under non-corrosive conditions was observed under a metallographic microscope. The results show that there are very dispersed non-metallic inclusions such as sulfides and silicates on the austenite matrix. Under certain conditions, carbides may also be observed. Due to different chemical compositions, there are many grades available, but there is no significant difference in corrosion resistance between them. Alloy 400 alloy is more corrosion-resistant than pure nickel in reducing media and more corrosion-resistant than pure copper in oxidizing media.
Alloy 400 mechanical properties:
Tensile strength σB≥450MPa.
Yield strength σB≥170Mpa.
Elongation: δ≥30%.
Alloy 400 corrosion resistance:
Alloy 400 Monel alloy generally has better corrosion resistance than nickel and copper. It is more resistant to corrosion by reducing media than pure nickel, and pure copper is also very corrosive to sulfuric acid, phosphoric acid and carbon. Especially resistant to corrosion by hydrochloric acid and hot concentrated alkali. Alloy 400 alloy has excellent corrosion resistance in fluorine gas, hydrochloric acid, sulfuric acid, hydrofluoric acid and their derivatives. Alloy 400 is a deformable nickel-copper-nickel-based alloy. It has good seawater corrosion resistance, chemical corrosion resistance and chloride ion stress corrosion cracking resistance. This alloy is one of the few available for fluoride. It has good resistance to oxidative stress fission corrosion in hydrofluoric acid and fluorine-containing gas media such as seawater and brine. Alloy 400 also has excellent corrosion resistance in moderately concentrated alkaline and salt solutions. In cold alkaline environments, the alloy is used with weak acids such as sulfur and hydrogen fluoride.
Acidic media: Alloy 400 is corrosion-resistant in sulfuric acid with a concentration of less than 85%. Alloy 400 is one of the few important materials resistant to hydrofluoric acid.
Water corrosion: Alloy 400 alloy has excellent corrosion resistance under most water corrosion conditions, with little pitting corrosion and stress corrosion, and the corrosion rate is less than 0.025mm/A.
High temperature corrosion: The maximum temperature for Alloy 400 to work continuously in the air is generally around 600°C. In high temperature steam, the corrosion rate is less than 0.026mm/A. Ammonia: Due to the high nickel content in Alloy 400 alloy, it is corrosion resistant under anhydrous ammonia and ammoniation conditions below 585°C.
Alloy 400 alloy welding materials: ENiCu-7, ERNiCu-7
Application areas of Alloy 400 alloy: marine heat exchangers, desalination equipment, salt production equipment, marine and chemical processing equipment, drive shafts and water pumps, gasoline and water tanks, etc.
