SAF 2205 is the Alleima tradename for their 22% chromium duplex stainless steel, more widely known by its UNS designation S32205 (also S31803) and referenced as DIN 1.4462 and ASTM A182 F60. It is commonly called Duplex 2205.

SAF 2205 combines high strength with strong resistance to localised corrosion. SAF stands for Alleima Austenitic Ferritic, reflecting the duplex structure of roughly equal proportions of austenite and ferrite. The 2205 designation corresponds to UNS S32205, an improved development of the earlier S31803 with more tightly controlled composition for greater corrosion resistance.

Chemical composition

Element Typical content
Chromium 22%
Nickel 5-6%
Molybdenum Present
Nitrogen 0.15-0.20%

The balance is iron with controlled levels of manganese, silicon and trace elements. This gives a strong combination of mechanical strength and resistance to localised corrosion.

Key properties

  • High strength, approximately double that of 316L austenitic stainless steel
  • Excellent resistance to chloride stress corrosion cracking
  • Very good pitting and crevice corrosion resistance from its chromium, molybdenum and nitrogen content
  • Good weldability with the correct procedures
  • Improved fatigue strength compared with austenitic stainless steels

Applications

SAF 2205 is used across industries that need strength and corrosion resistance, including:

  • Oil and gas production: piping, risers, subsea equipment
  • Chemical and petrochemical processing
  • Pulp and paper bleaching equipment
  • Marine and offshore structural components, fasteners and shafts
  • Desalination and water treatment plants

Comparison with other duplex grades

  • Versus S31803: SAF 2205 offers enhanced corrosion resistance through tighter composition control.
  • Versus super duplex grades (S32760, Ferralium® 255): SAF 2205 has lower corrosion resistance and strength, but is more cost-effective.
  • Versus 316L: SAF 2205 delivers higher strength and better resistance to stress corrosion cracking in chloride environments.

Standards and designations

  • UNS S32205
  • DIN 1.4462
  • ASTM A182 F60
  • EN 1.4462
  • ISO 31803

Availability

We stock SAF 2205 in both bar and plate, available ex-stock in the USA. In the UK, it is stocked in bar and hollow bar only.

Further reading