SAF 2205, is
Alleima
owned trademark (Formerly Sandvik Materials Technology) 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 Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

, 5%

nickel Nickel is a chemical element; it has 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 slo ...

, 3.2%

molybdenum Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals hav ...

and other

alloying elements An alloy is a mixture of chemical elements of which in most cases at least one is a metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have properties ...

such as

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

and

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

. 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 Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can lead to unexpected and sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. SC ...

(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 Tribocorrosion is a material degradation process due to the combined effect of corrosion and wear. The name tribocorrosion expresses the underlying disciplines of tribology and corrosion. Tribology is concerned with the study of friction, lubrica ...

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 t ...

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 SAE 316L grade stainless steel, sometimes referred to as A4 stainless steel or marine grade stainless steel, is the second most common austenitic stainless steel after 304/A2 stainless steel. Its primary alloying constituents after iron, are chr ...

. 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

{{reflist

External links

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

See also

References

External links