No. 20 alloy products

Alloy 20

American standard grade Alloy20, UNS N08020, national standard grade NS143, 0 Cr20Ni35Mo3Cu3Nb. It is a nickel-iron-chromium austenitic alloy, originally developed to resist the corrosion of acids, especially sulfuric acid, and has good corrosion resistance in concentrated sulfuric acid below 50 ℃. It has excellent resistance to stress corrosion cracking and local corrosion resistance to oxidation and medium reduction corrosion. The alloy, with the addition of copper and molybdenum, resists harsh environments, pitting and crevice corrosion. It also contains niobium, which minimizes carbide precipitation during welding and reduces the risk of intergranular corrosion. At the same time, the alloy also has excellent mechanical properties and processing properties.

The heat treatment state of alloy 20 is the stabilization annealing treatment of 927~1010 ℃, and it is not suitable to be hot processed at the sensitive temperature of intergranular corrosion of 650 ℃. The chemical processing industry, hot seawater and hydrometallurgy are widely used. Mainly used to deal with hot H2SO4, chloride solution, Na2SO3 and other environmental heat exchangers, pipes, valves, pumps, etc.


Standard for 20# alloy forgings

American Standard Forging Standard: ASTM B462-2002

National standard forgings standard: GB/T 37620-2019