◆ Introduction

Duplex Stainless Steel (DSS for short) refers to stainless steel with ferrite and austenite each accounting for about 50%, and the content of less phases generally needs to reach at least 30%. In the case of low C content, the Cr content is 18%~28%, and the Ni content is 3%~10%. Some duplex stainless steel grades also contain alloying elements such as Mo, Cu, Nb, Ti, N, etc.

Super duplex stainless steel coil has the characteristics of both austenitic and ferritic stainless steel. Compared with ferrite, it has higher plasticity and toughness, no room temperature brittleness, and significantly improved intergranular corrosion resistance and welding performance. At the same time, it also maintains the 475°C brittleness of ferritic stainless steel, high thermal conductivity, and superplasticity. Compared with austenitic stainless steel, it has high strength and significantly improved resistance to intergranular corrosion and chloride stress corrosion.

Duplex stainless steel coil has excellent pitting corrosion resistance and is also a nickel-saving stainless steel.Chinese duplex stainless steel coils are classified according to chemical composition and can be divided into four types: Cr18 type, Cr23 (excluding Mo), Cr22 type and Cr25 type. Cr25 duplex stainless steel is divided into ordinary type and super duplex stainless steel coil. The specific grades of duplex stainless steel grades are 2205, 2304, 2507, etc.