Austenitic low temperature steel has high low temperature toughness and generally has no ductile-brittle transition temperature.Depending on the composition of the alloy, it can be divided into three series:
Low temperature steel sheath fe-cr-ni system
Fe - Ni - Cr.Mainly 18-8 cr-ni stainless and acid - resistant steel.The steel toughness at low temperature, good corrosion resistance and manufacturability has different degree of all kinds of cryogenic applications (150 ~ 269 ℃) technology.
the Fe - Ni - Cr - Mn and Fe - Ni - Cr - Mn - N
The fe-cr-ni-mn and fe-cr-ni-mn-n systems.This type of steel stabilizes the austenite by replacing some nickel with manganese and nitrogen.Nitrogen also strengthens the properties of steel with high toughness, extremely low permeability and stable austenitic structure, which is suitable for use in ultra-low-temperature non-magnetic steels (that is, materials with low permeability).Such as cr21ni6mn9n 0 and 0 cr16ni22mn9mo2 no magnetic structure parts in - 269 ℃.
Low temperature steel: mild steel with austenite of Fe-Mn-Al system
Fe-mn-al series austenitic low temperature nonmagnetic steel.Is developed by China to save the new steel grade of chromium, nickel, such as 15 mn26al4 part can replace cr-ni austenitic steel, used to - 196 ℃ under extremely low temperature area.If the resistance of the steel to chemical corrosion can be improved, the scope of application can be expanded.