What is UNS S31803 material?

UNS S31803 is a duplex stainless steel based upon a 22% chromium content. It is also identified at DIN 1.4462 and ASTM A182 F51.

Developed in the 1930s for application in paper and pulp manufacture, it provided twice the strength and provide a significant uplift in corrosion resistance compared to the more general 304/316 stainless steel grades. 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.

UNS S32205 is a very similar grade to UNS S31803 and is widely offered. Some time ago, a number of the leading manufacturers of duplex stainless steel were consistently producing this grade to the upper end of the allowable specification. This reflected their desire to maximise the corrosion performance of the alloy, aided by the development of the AOD steelmaking process which allowed tighter control of composition. In addition, it also allowed the level of nitrogen additions to be influenced, rather than just present as a background element. Controlling nitrogen, chromium and molybdenum content to the upper end of the allowable specification for S31803 results in better and more consistent corrosion resistance.

To differentiate the duplex stainless steel produced at the top end of the composition range, a further specification was introduced, namely UNS S32205, although this still meets the DIN 1.4462 caption. Duplex stainless steel made to the S32205 (F60) caption will fully meet the S31803 (F51) caption, whereas the reverse is not true. Therefore, S32205 can be dual-certified as S31803.

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.

For More Information  

For more information about our range of alloys, please contact Langley Alloys today.