Ferralium 255 – 3AF Aged Grade (UNS S32550)

Ferralium^® 255 – 3AF is a super duplex stainless steel which is supplied in either a hot worked condition, annealed or aged condition.

By subjecting the product to an additional ageing process, it is possible to further increase the tensile strength of the product whilst retaining the products high levels of ductility.

As a variant of our unique Ferralium^® 255 – SD50 product, it is a 25% Cr alloy with significant additions of Cu, offering excellent corrosion resistance in a wide variety of corrosive chemicals including sulphuric, nitric and phosphoric acid.  When exposed to seawater and other chloride containing environments, it also provides outstanding resistance to pitting and crevice corrosion, with a critical pitting temperature exceeding 50°C.

Excellent ductility and impact strength are retained at both ambient and sub-zero temperatures, despite the elevated strength levels. These are also combined with a high resistance to abrasion, erosion and cavitation erosion. Listed in NACE MR 01 75 for sour service and having gained ASME Approval for Pressure Vessel applications, Ferralium^® 255-3AF is tested to the highest degree using tests designed to guarantee that the trade-marked product possesses high integrity, a correct phase balance and the absence of sigma and other deleterious phases.