Ferritic stainless steel (400 series) contains 15% to 30% chromium and has a body-centered cubic crystal structure. This type of steel generally does not contain nickel, and sometimes contains a small amount of Mo, Ti, Nb and other elements. This type of steel has the characteristics of high thermal conductivity, low expansion coefficient, good oxidation resistance, excellent stress corrosion resistance, etc., and is mostly used to manufacture parts resistant to atmospheric, water vapor, water and oxidizing acid corrosion.
Stainless steel with ferrite as the main structure in use, Cr mass fraction of 11% to 30%, with a body-centered cubic crystal structure. Compared with austenitic stainless steel, this type of steel generally does not contain Ni, and sometimes contains a small amount of Mo, Ti, Nb and other elements. The application of out-of-furnace refining technology (AOD, Argon Oxygen Decarburization) and VOD (Vacuum Oxygen Decarburization) can greatly reduce interstitial elements such as C and N. It has the advantages of saving Ni, low price, good stress corrosion resistance, and good oxidation resistance. It is mostly used in environments that resist corrosion from the atmosphere, water vapor, water vapor and oxidizing acids. It has a certain corrosion resistance in dilute nitric acid and weak organic acids at room temperature, so this type of steel is widely used. However, it is not resistant to corrosion from media such as reducing acids. General ferritic stainless steel has the disadvantages of poor impact toughness, poor plasticity and corrosion resistance after welding, sensitivity to intergranular corrosion, and poor pitting resistance, which limits its use.
high temperature stainless steel pipe
