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What is Duplex Stainless Steel Flange?

Duplex stainless steel flanges are stainless steel with ferrite and austenite components each accounting for about 50%, and the equivalent content must reach 30%. In the case of low C content, the Cr content is between 18% and 28%, and the Ni content is between 3% and 10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, N, etc.

The commonly used materials for duplex stainless steel flanges include S22253, S22053, S23043, etc.

The duplex stainless steel flange contains the characteristics of austenitic and ferritic stainless steel. Compared with ferritic stainless steel, it has higher plasticity and toughness, no room temperature brittleness, and significantly improved welding performance and intergranular corrosion resistance. At the same time, it maintains the 475 ℃ brittleness and high thermal conductivity of ferritic stainless steel, and has characteristics such as superplasticity. Compared with austenitic stainless steel flanges, it has higher strength and significantly improved resistance to intergranular corrosion and oxide stress corrosion. The duplex stainless steel flange also has good resistance to hole corrosion.

Dual phase stainless steel flanges also have a dual phase structure of austenite and ferrite, characterized by higher yield strength and tensile strength than austenitic or ferritic stainless steel forgings. Another characteristic of duplex stainless steel flanges is their strong resistance to localized corrosion, such as pitting corrosion, crevice corrosion, and stress corrosion. Therefore, duplex stainless steel flanges are particularly suitable for use in seawater corrosion, seawater erosion corrosion, media rich in Ci ions, and acidic media. Double phase stainless steel flanges are also widely used in the manufacturing of heat exchangers, PTA, FGD devices, condensers, and other environments that are resistant to seawater, high temperature, and concentrated nitric acid in refining, fertilizers, papermaking, petrochemicals, and other industries. The defects of duplex stainless steel flanges are high cost and long production period, but their stability and reliability in use that are better than other forgings.