Common grades

S31803/S32205, S31500, S32304, S32750, S32760,

       

Common standards

ASTM A789 (ASME SA789) General purpose seamless and welded ferritic/austenitic stainless steel pipe

ASTM A790 (ASME SA790) Seamless and welded ferritic/austenitic stainless steel nominal pipe

GB/T 21833-2008   Austenitic - ferrite grades duplex stainless steel seamless steel tube

Duplex stainless steel tube/super duplex stainless steel tube is composed by and phrase organization of the austenitic and ferritic about half and half of the proportion. For It possessed both austenite and ferrite stainless steel characteristics, so it owns high strength and corrosion resistance of stainless steel. Usually, in the case of low carbon content of C, Cr content is about 18% ~ 28%, Ni content is about 3%-10%, Some steel 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 ℃ brittleness and high thermal conductivity, it has the characteristic of superplasticity.  Compared with austenitic stainless steel, the yield strength increased significantly, the resistance to intergranular corrosion, stress corrosion and corrosion fatigue and abrasion performance improved significantly.