Alloy 2205 is a 22% Cr duplex stainless steel, supplied in the solution annealed condition. As a duplex stainless steel, it combines the desirable aspect of properties of both austenitic and ferritic grades. The high chromium, molybdenum and nitrogen contents results in a Pitting Resistance Equivalent number (PREN) of 33-34, providing pitting and crevice corrosion resistance superior to Alloy 316L or Alloy 317L austenitic stainless steels in almost all corrosive media. Due to its excellent corrosion properties, it is well-suited to environments containing chlorides and hydrogen sulphide, for use in oil and gas extraction from sour wells, in refineries and in process solutions contaminated with chlorides.
It also has good erosion fatigue properties as well as lower thermal expansion and higher thermal conductivity than austenitic steels. The yield strength is about twice that of austenitic stainless steels, allowing a designer to save weight and make the alloy more cost competitive when compared to Alloy 316L or Alloy 317L.