SA-789 Uns S31803 U Bend Tube for Heat Exchanger

(super) duplex stainless steel tube

Biphase stainless steel has two phase structure, which makes it the best stainless steel with high strength and corrosion resistance. Generally, in the case of low C, the Cr content is 18%~28% and the Ni content is 3%~10%. Some steels also contain Mo, Cu, Nb, Ti, N and other alloy elements.

Compared with ferrite, plasticity and toughness is higher, there is no room temperature brittleness, intergranular corrosion resistance and welding performance were significantly increased, while maintaining a ferritic stainless steel of 475 ºC brittleness and high thermal conductivity, has the characteristics of superplasticity. Compared with austenitic stainless steel, yield strength is improved, intercrystalline corrosion resistance, stress corrosion, corrosion fatigue and abrasion performance are improved.

Major brands: S31803/S32250, S32750, S32760, S31500, S31500, 32001, S32003, S32304

Main ingredients:

Common standards:

ASTM A789 (ASME SA789)

General purpose seamless and welded ferrite/austenitic stainless steel pipe

ASTM A790 (ASME SA790)

Seamless and welded ferrite/austenitic stainless steel nominal pipe

ASTM A928 (ASME SA928)

Standard specification for filler metal electrofusion welding ferrite/austenite (duplex) stainless steel tubing
 

Performance features:

1. Excellent comprehensive corrosion resistance and partial corrosion resistance, especially stress corrosion resistance, pitting corrosion resistance, crevice corrosion resistance, corrosion fatigue resistance and abrasion resistance

2. Good weldability

3. Good comprehensive mechanical properties

4. Good intercrystalline corrosion resistance

5. High cost performance and long service cycle