Duplex stainless steel pipes - (super) duplex stainless steel pipes.
Duplex stainless steel is available in 4 grades.
1: Low alloy type: S31500, S32001, S32003, S32304
S31500 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 180~19.0, nickel: 45~5.25, molybdenum: 25~3.0, nitrogen: 005~0.10. Tensile strength 630, yield strength 440, elongation: 30
S32001 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 195~21.5. Nickel: 10~3.0 , Molybdenum: 060, Copper: 10, nitrogen: 005~0.17. Tensile strength 620, yield strength 450, elongation: 25
S32003 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 195~22.5, nickel: 30~4.0, molybdenum: 15~2.0, nitrogen: 014~0.20, tensile strength 620, yield strength 450, elongation: 25
S32304 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 215~24.5, nickel: 30~5.5, molybdenum: 005~0.60, copper: 005~0.60, nitrogen: 005~0.20, tensile strength 600, yield strength 450, elongation: 25
2: Medium alloy type: S31803, S32205, S31803 duplex stainless steel Composition: Carbon: 003, Chrome: 210~23.0, nickel: 45~6.5, molybdenum: 25~3.5. Nitrogen: 008~0.20, tensile strength 620, yield strength 400, elongation: 25
S32205 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 220~23.0, nickel: 45~6.5, molybdenum: 30~3.5. Nitrogen: 014~0.20, tensile strength 655, yield strength 450, elongation: 25
3: High alloy type: S32550, S32550 duplex stainless steel Composition: Carbon: 004, Chrome: 240~27.0, nickel: 45~6.5, molybdenum: 29~3.9, copper: 15~0.25, nitrogen: 010~0.25, tensile strength 760, yield strength 485, elongation: 15
4: Super DSS: S32750, S32760, S32750 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 240~26.0, nickel: 60~8.0, molybdenum: 30~5.0, copper: 05. Nitrogen: 024~0.32, tensile strength 800, yield strength 550, elongation: 15
S32760 Duplex Stainless Steel Composition: Carbon: 003, Chrome: 240~26.0, nickel: 60~8.0, molybdenum: 30~4.0, copper: 05~1.0, nitrogen: 020~0.30, tensile strength 750, yield strength 550, elongation: 25
Super) duplex stainless steel pipes.
Duplex stainless steel has a +y duplex structure, so its performance is built with the characteristics of austenitic stainless steel and ferritic stainless steel, which is a type of stainless steel with the best strength and corrosion resistance. Usually, at a low C content, CR contains.
The amount is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, N, etc.
Compared with ferrite, it has higher plasticity, toughness, no brittleness at room temperature, improved intergranular corrosion resistance and welding performance, and also maintains the 475 brittleness and high thermal conductivity of ferritic stainless steel, with superplasticity and other characteristics.
Compared with austenitic stainless steel, the yield strength is significantly improved, and the resistance to crystal erosion, stress corrosion, corrosion fatigue and abrasion is significantly improved.
Common standards for duplex stainless steel pipes:
ASTM A789 (ASME SA789) General Purpose Seamless and Welded Ferrite Austenitic Stainless Steel Tubing, ASTM A790 (ASME SA790) Seamless and Welded Ferritic Austenitic Stainless Steel Pipe, ASTM A928 (ASME SA928) Packing Metal Electrofusion Welded Ferritic Standard Specification for Austenitic (Duplex) Stainless Steel Tubing, GB T 21832-2008 Austenitic-Ferritic Duplex Stainless Steel Welded Steel Pipe, GB T 21833-2008 austenitic-ferritic duplex stainless steel seamless steel pipe,
Performance characteristics of duplex stainless steel pipes:
1.Excellent resistance to comprehensive corrosion and local corrosion, especially stress corrosion resistance, pitting corrosion resistance, crevice corrosion resistance, corrosion fatigue resistance and wear resistance.
2.Good weldability.
3.Good comprehensive mechanical properties.
4.Good resistance to intergranular corrosion.