What is the UNS number for super duplex stainless steel?

Super duplex stainless steels are grades that have a combination of austenitic and ferritic microstructures, based upon a chromium content of 25%. There have been a large number of grades developed over the last 50 years that meet this basic classification. However, the most popular ones are described below.

UNS S32550 equates to Ferralium 255, DIN 1.4507 and ASTM A182 F61. Ferralium 255 is the original super duplex stainless steel invented by Langley Alloys. Launched in 1969, it has now provided more than 50 years of successful service in a wide range of demanding applications. Compared with F53 and F55 it delivers increased strength and corrosion performance. Its minimum yield strength as solid bars exceeds 85ksi, whereas other grades are limited to 80ksi. In addition, it contains up to 2.0% of copper, which aids in pitting corrosion resistance. Langley Alloys stocks Ferralium 255-SD50 in sizes from 5/8” to 14” (15.87-355.6mm) diameter solid bar, plus plates up to 3” (76.2mm) thickness plus pipes, flanges and fittings.

UNS S32750 equates to DIN 1.4410 and ASTM A182 F53. This is the 25% Cr super duplex stainless steel originally developed by Sandvik (now Alleima) and marketed as SAF2507. Langley Alloys stocks S32750 solid bars in sizes from 5/8” to 20” (15.87-508mm) diameter, plate up to 3” (76.2mm) thick, plus pipes in scheduled sizes, fittings and flanges.

UNS S32760 equates to DIN 1.4501 and ASTM A182 F55. The origins of this grade can be traced back to the development of Zeron 100 by Platt & Mather, Manchester UK. It is another super duplex stainless steel based upon a 25% Cr composition, but with an addition of tungsten. Langley Alloys stocks S32760 solid bars in sizes from 5/8” to 20” (15.87-508mm) diameter, plate up to 3” (76.2mm) thick, plus pipes in scheduled sizes, fittings and flanges.

For More Information  

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