It is a stainless steel that accounts for about half of the austenite and ferrite structures. In the case of a lower C content, the Cr content is between 18% and 28%, and the Ni content is between 3% and 10%. Some steels also contain alloying elements such as Mo, Cu, Si, Nb, Ti, and N. This type of steel combines the characteristics of austenitic and ferritic stainless steel. Compared with ferrite, it has higher plasticity, toughness, no room temperature brittleness, resistance to intergranular corrosion and weldability, and iron retention. The stainless steel has a brittleness at 475 ° C and a high thermal conductivity, and is characterized by superplasticity. Compared with austenitic stainless steel, it has high strength and resistance to intergranular corrosion and chloride stress corrosion resistance. Duplex stainless steel has excellent pitting corrosion resistance and is also a nickel-saving stainless steel.