Duplex stainless steel refers to stainless steel in which ferrite and austenite each account for about 50%, and generally the content of less phases needs to reach at least 30%. In the case of low carbon content, the chromium content is 18%~28%, and the nickel content is 3%~10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, and N.
Duplex stainless steels combine the characteristics of austenitic and ferritic stainless steels. Compared with ferrite, it has higher plasticity and toughness, no room temperature brittleness, significantly improved intergranular corrosion resistance and welding performance, and also maintains 475°C brittleness and high thermal conductivity of ferritic stainless steel, with superplasticity, etc. features.
Compared with austenitic stainless steel, it has high strength and significantly improved resistance to intergranular corrosion and chloride stress corrosion. Duplex stainless steel has excellent pitting corrosion resistance and is also a nickel-saving stainless steel.
