ASTM A789 UNS S31803 Duplex 2205 Tube

 

: It strictly adheres to the ASTM A789/ASME SA - 789 standard, which is the authoritative specification for duplex stainless steel tubes formulated by the American Society for Testing and Materials. It also aligns with related standards such as ASTM A790 and ASTM A928.

: The tubing is available in both seamless and welded types. The seamless version typically covers an outer diameter range of 6.0 - 630mm, with wall thickness from 0.6mm to 6.0mm, and lengths usually ranging from 1 - 6 meters, which can be customized as needed. Common end treatments include beveled ends and plain ends, and surface finishes are diverse, such as annealed & pickled, bright annealed, and polished surfaces.

The chemical composition of this tube is precisely proportioned to ensure its dual - phase structure and performance. The specific components (maximum or range percentage) are as follows: Chromium (21.0 - 23.0%), Nickel (4.50 - 6.50%), Molybdenum (2.50 - 3.50%), Nitrogen (0.14 - 0.20%), Carbon (<=0.030%), Manganese (<=2.00%), Silicon (<=1.00%), Phosphorus (<=0.030%), Sulfur (<=0.020%), and Iron as the balance element. The addition of nitrogen not only enhances its corrosion resistance but also improves its weldability.