Introduction to the types, chemical composition, characteristics and uses of Monel alloy grades Monel

Introduction to the types, chemical composition, characteristics and uses of Monel alloy grades Monel
alloy grades: Monel 400, Monel K500; Monel
400 (UNS N04400, NCu30) The structure of Monel 400 alloy is a high-strength single-phase solid solution. It is a corrosion-resistant alloy with the largest amount, the widest application and excellent comprehensive performance. This alloy has excellent corrosion resistance in hydrofluoric acid and fluorine gas media, and also has excellent corrosion resistance to 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 cracks and has good cutting performance. 
Chemical composition (%): Ni: balance; Cu: 28-34; Si: <0.5; Mn: <2.0; C: <0.30; Fe: <2.0;
Monel K500 (UNS N05500) Monel     
K500 alloy has excellent mechanical properties such as high strength, corrosion resistance and non-magneticity, and also has the same corrosion resistance as Monel 400. It can be used as a pump shaft material and is suitable for working under the harsh geological mining conditions of high sulfur and high wax oil layers. Since the alloy has no plastic-brittle transition temperature, it is very suitable for various low-temperature equipment. This alloy is mainly used for pump shafts and valve stems, conveyor scrapers, oil well drilling rings, elastic components, valve pads, etc. It is suitable for petroleum, chemical, shipbuilding, pharmaceutical, and electronic sectors. The chemical composition of this alloy is roughly the same as that of Monel 400. The biggest difference is that it contains 2.3-3.15% A1 and 0.30-1.00% Ti. The structural characteristics of this alloy are the same as those of Monel 400 except for the precipitation of dispersed Ni3 (A1, Ti) precipitate phase. 
Chemical composition (%): Ni:>63; Cu:27/33; Mn<1.5; Fe<2;Si<0.5; A1 2.3/3.15; Ti0.35/0.85;
Corrosion resistance: This alloy has excellent corrosion resistance in fluorine gas, hydrochloric acid, sulfuric acid, hydrofluoric acid and their derivatives. At the same time, it is more corrosion resistant than copper-based alloys in seawater. 
Acid medium: M400 is corrosion resistant in sulfuric acid with a concentration of less than 85%. M400 is one of the few important materials that can withstand hydrofluoric acid.
Water corrosion: In most water corrosion conditions, M400 alloy not only has excellent corrosion resistance, but also rarely suffers from pitting corrosion and stress corrosion, with a corrosion rate of less than 0.25mm/a. 
High temperature corrosion: The maximum temperature at which M400 can work continuously in 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 of Monel 400 alloy, it can withstand corrosion under anhydrous ammonia and ammoniation conditions below 585°C.