S31803 DUPLEX STEEL PIPE/TUBE

https://www.nickelalloytubes.com/products/s31803-duplex-steel-pipe-tube.html

astm a790 uns s31803 is also known as grade 2205. The duplex stainless steel family includes a wide range of different materials, however, the astm a815 s31803 is the most common one. Duplex-grade stainless steel alloys have ferritic/austenitic properties, giving these materials superior strength and excellent resistance to oxidation.