S31803 is a duplex stainless steel based on a chromium content of 22% and can also be referenced as DIN 1.4462 and ASTM A182 F51 when supplied as round bar.
Developed in the 1930s for application in paper and pulp manufacture, it provided twice the strength and a significant uplift in corrosion resistance compared to the more general 304/316 stainless steel grades. The Pitting Resistance Equivalent Number (PREN) is a convenient way to compare the general corrosion resistance of different alloys, and it is calculated from the content of chromium, molybdenum, and nitrogen. S31803 has a PREN of up to 34, compared with a value of 25 for 316, reflecting much improved corrosion resistance. This made them an excellent choice for the engineer looking for a material suitable for an application in a corrosive environment. Their use has broadened to include marine applications, food and chemical processing industry and general engineering.
It is possible to produce this alloy to a tighter range of composition, which ensures the product always achieves the best possible corrosion resistance – by controlling the chromium, molybdenum and nitrogen levels to the upper end of the specification. This grade is referenced S32205 and ASTM A182 F60, although still DIN 1.4462.
Langley Alloys stocks S32205, which can also be supplied as S31803 – effectively dual-certified. Langley Alloys stocks S32205 (2205) duplex stainless steels as round bars from 5/8”-20” diameter (15.87-508mm), plate up to 3” (76.2mm) thickness, as well as pipes in scheduled sizes, flanges and fittings. S32750 and S32760 are also available in a similar size range ex-stock.
For more information about our range of alloys, please contact Langley Alloys today.