25Cr is shorthand for super duplex stainless steel, based on a composition of around 25% chromium.
How 25Cr differs from standard stainless steel
Chromium is a normal component of stainless steel, where it provides resistance to oxidation. Raising the chromium level increases that resistance, and the 25Cr super duplex grades combine high strength, excellent corrosion resistance and lower cost than more highly alloyed grades.
The main 25Cr grades
We have a strong focus on this family of alloys:
- Ferralium® 255 (UNS S32550, DIN 1.4507, F61) is the original super duplex stainless steel, patented by Langley Alloys in 1968. It is still the only super duplex to provide a yield strength >85ksi, and its increased copper content (2%) gives greater resistance to acids.
- S32750 (UNS S32750, DIN 1.4410, ASTM F53) was originally developed as SAF2507 in the 1980s by Alleima.
- S32760 (UNS S32760, DIN 1.4501, ASTM F55) was originally developed as Zeron 100 by the UK company Mather & Platt in the 1970s. It contains slightly higher copper and tungsten than S32750.
We carry an extensive stock of these super duplex grades, with bar up to 16" (406.4mm) diameter, plate up to 3" (76.2mm) thickness, and a variety of pipes and fittings ex-stock from our warehouses in the UK and USA.