Material grade: Monel 400 (Monel) alloy
US grade: UNS N04400
German grade: 2.4360
Monel400 (N04400) Monel alloy is a corrosion-resistant alloy with the largest amount, the most widely used and excellent comprehensive properties. This alloy has excellent corrosion resistance in hydrofluoric acid and fluorine gas medium, and also has excellent corrosion resistance in hot concentrated alkali solution. At the same time, it is also resistant to corrosion by 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 machinability.
The chemical composition of Monel400 alloy is mainly composed of 30% Cu and 65% Ni, plus a small amount of Fe (1%-2%), and the structure is a typical single-phase austenite structure. Since nickel and copper are mutually soluble in any proportion, there is generally no intermetallic phase precipitation. The microstructure of this alloy is observed under non-etching conditions under a metallographic microscope, and it can be seen that there are very dispersed non-metallic inclusions, such as sulfides and silicates, on the austenite matrix. Carbides may also be observed under certain conditions. Due to the difference in chemical composition, it can have a variety of alloy grades, but there is no significant difference in corrosion resistance between them. Monel400 alloy is more resistant to corrosion by reducing media than pure nickel, and more resistant to corrosion by oxidative media than pure copper.
(1) The corrosion resistance of Monel is generally better than that of nickel and copper. It is more resistant to corrosion by reducing media than pure nickel, and is more resistant to corrosion by oxidative media than pure copper. Corrosion resistance to sulfuric acid, phosphoric acid, and carbon very good. In particular, it is resistant to corrosion by hydrochloric acid, and 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.
At the same time, it is more resistant to corrosion than copper-based alloys in seawater. Monel400 is a deformable nickel-copper-based nickel-based alloy with good seawater corrosion resistance and chemical corrosion resistance, as well as chloride stress corrosion cracking resistance. 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 media, such as seawater and saltwater environments. Monel 400 also has very good corrosion resistance in moderately concentrated alkaline and salt solutions. In cooler alkaline environments, the alloy is used in weak acids such as sulfur and hydrogen fluoride.
(2) Acid medium: Monel400 is corrosion-resistant in sulfuric acid with a concentration of less than 85%. Monel400 is one of the few important materials that can resist hydrofluoric acid.
(3) Water corrosion: In most cases of water corrosion, Monel400 alloy not only has excellent corrosion resistance, but also pitting corrosion and stress corrosion are rarely found, and the corrosion rate is less than 0.025mm/a.
(4) High temperature corrosion: The maximum temperature of Monel400 working continuously in air is generally around 600℃, and in high temperature steam, the corrosion rate is less than 0.026mm/a. Ammonia: Due to the high nickel content of Monel400 alloy, it is resistant to corrosion under anhydrous ammonia and ammoniated conditions below 585°C.
Monel Monel400 electrode (ENiCu-7), Monel400 welding wire (ERNiCu-7)
Marine heat exchangers, desalination equipment, salt production equipment, marine and chemical processing equipment, propeller shafts and pumps, gasoline and water tanks, etc.