SAF 2205, also known as Sandvik SAF 2205, is a

Sandvik Sandvik AB is a Swedish multinational engineering company specializing in metal cutting, digital and additive manufacturing, mining and construction, stainless and special steel alloys, and industrial heating. The company was founded in Swed ...

-owned trademark for a 22Cr duplex (ferritic-austenitic) stainless steel. ''SAF'' derives from ''S''andvik ''A''ustenite ''F''errite. The nominal chemical composition of SAF 2205 is 22% chromium, 5%

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...

, 3.2% molybdenum and other

alloying elements An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility ...

such as

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

and

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

. The UNS designation for SAF 2205 is S31803/S32205 and the EN steel no. is 1.4462. SAF 2205 or Duplex 2205 is often used as an alternative to expensive 904L stainless steel owing to similar properties but cheaper ingredients. Duplex stainless steel is available in multiple forms like bars, billets, pipes, tubes, sheets, plates and even processed to fittings and flanges. Typical properties of SAF 2205 duplex stainless steel are: * high resistance to stress corrosion cracking (SCC) in chloride-bearing environments * high resistance to stress corrosion cracking (SCC) in environments containing hydrogen sulphide * high resistance to general corrosion,

pitting corrosion Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal. The driving power for pitting corrosion is the depassivation of a small area, which becomes anodic (oxidation re ...

, and

crevice corrosion Crevice corrosion refers to corrosion occurring in occluded spaces such as interstices in which a stagnant solution is trapped and not renewed. These spaces are generally called crevices. Examples of crevices are gaps and contact areas between pa ...

* high resistance to erosion corrosion and corrosion fatigue * high mechanical strength - roughly twice the proof strength of austenitic stainless steel * good

weldability The weldability, also known as joinability,. of a material refers to its ability to be welded. Many metals and thermoplastics can be welded, but some are easier to weld than others (see Rheological weldability). A material's weldability is used to ...

Duplex 2205 Stainless Steel (both austenitic and ferritic) is used in applications that require strength and good corrosion resistance. S31803 was endorsed in year 1996 whereas it underwent number of changes that led to discovery of UNS S32205 which is more widely used. Possible alternates for SAF 2205 are 904L Stainless Steel, UR52N+, 6%Mo and 316L. Applications of SAF 2205 are in the following industries: * Transport, storage and chemical processing * Processing equipment * High chloride and marine environments * Oil and gas exploration * Paper machines, liquor tanks, pulp and paper digesters

References

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External links

Technical data for SAF 2205 (seamless tube and pipe)
Alloys Stainless steel

See also

References

External links