Main grades: S31803/S32750, S32750, S32760
It has good corrosion resistance with high strength. Content of Cr is between 18%-28% and Ni is 3%-10% in the condition of low C. Some steels also contain the alloy elements such as Mo, Cu, Nb, Ti and N, etc.
(Super) Duplex Stainless Steel
Duplex stainless steel (DSS) is featured with structure of two phases (α and γ) and has characteristics of both ferritic and austenitic stainless steel. It has good corrosion resistance and high strength. It is alloyed with 18%-28% Cr and 3%-10% Ni in the condition of low C. Some steels also contain the alloy elements such as Mo, Cu, Nb, Ti and N, etc.
Comparing with ferritic stainless, duplex stainless steel has higher plasticity, ductility and better intergranular corrosion resistance and weldability. It keeps same 475℃ brittleness with ferritic stainless and high thermal conductivity. Duplex has improved yield strength, resistance to intergranular corrosion, stress corrosion, corrosion fatigue and abrasion & corrosion compared with austenitic stainless steel.
Grades：S31803/S32205, S32750, S32760, S31500, 32001, S32003, S32304
ASTM A789 Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service
ASTM A790 (ASME SA790) Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASTM A928 (ASME SA928) Standard Specification for Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric Fusion Welded with Addition of Filler Metal
GB/T 21832-2008 Austenitic--Ferritic(duplex) grade stainless steel welded tubes and pipes
GB/T 21833-2008 Austenitic-Ferritic (duplex) grade stainlee steel seamless tubes and pipes
1. Superior resistance to general and local corrosion, especially to stress corrosion, pitting corrosion, crevice corrosion, corrosion fatigue and abrasion & corrosion;
2. Good weldability;
3. Good mechanical properties;
4. Excellent intergranular corrosion resistance;
5. High cost-effectiveness, long life time.
ASTM A268 Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service
JIS G3463 Stainless Steel for Boiler and Heat Exchanger Tubes
GB/T 30065 Welded ferritic stainless steel tubes for feedwater heater
GB/T 30066 Welded ferritic stainless steel tubes for heat-exchanger and condenser
1. High thermal conductivity;
2. Low expansion coefficient;
3. Good antioxidation property;
4. Excellent stress corrosion resistance.