Duplex 2205 (Duplex UNS S31803)

There is often confusion with Duplex grades since they have evolved rapidly. This results in 2205 including both UNS S31803 and UNS S32205 - there are small differences in the quantities of both Molybdenum and Nitrogen required/permitted. In common with other duplex steels it offeres greater strength and hardness.

The most commonly employed Duplex grade is 2205. It offers high strength, hardness, and excellent corrosion resistance. It possesses these qualities partly through the chemical composition but largely as a result of carefully controlling the temperature during the production process. This results a a steel composed of a mix of austenitic ferritic forms - hence the name "Duplex".

While duplex steels are generally more expensive per weight their increased strength allows for smaller sections to be used in fabrications resulting in savings in weight and often cost.