S32550 is the Unified Numbering System (UNS) designation for the original super duplex stainless steel, best known as Ferralium 255.
The UNS system was created by a number of trade groups working together in the 1970’s, to reduce confusion from the same alloy being called different things or vice-versa. Each metal is indicated by a letter followed by five numbers, where the letter indicates the family of metals i.e. S for stainless steels.
Ferralium 255 (UNS32550, DIN 1.4507, F61) is the original SDSS, developed by Langley Alloys in the 1960’s. It is still the only super duplex to provide a yield strength >85ksi, whilst it’s increased copper content (2%) ensures greater resistance to acids.
Langley Alloys carries an extensive stock of Ferralium 255, with bar up to 16″ (406.4mm) diameter, plate up to 3″ (76.2mm) thickness, and a variety of pipes and fittings available ex-stock from our warehouses in the UK and USA.
For more information about high-performance stainless steels alloys, please don’t hesitate to contact us today. We would be happy to answer any questions that you may have regarding specifications and common applications.