Ferralium® 255 is the super duplex stainless steel invented by Langley Alloys, combining high strength with excellent corrosion resistance thanks to a copper addition. It is most typically supplied in the hot worked and annealed condition.
We were founded in 1938, and by the 1970s had developed the world's first super duplex stainless steel, Ferralium®. It is used around the world across a wide range of applications and industries.
Strength and corrosion resistance
Ferralium® achieves higher strengths than other super duplex stainless steels through careful control of composition, manufacturing conditions and the ferrite:austenite ratio.
The increased copper addition enhances resistance to pitting and general corrosion, through a self-healing effect at pitting sites. This combination of strength and corrosion resistance lets designers reduce section size, which in turn can reduce weight and cost.
Applications
Ferralium® 255 offers strong corrosion resistance in chemical processes involving sulphuric, nitric or phosphoric acid, making it a good choice for the fertiliser and agrochemical industries. It has also been widely used in mining and pollution control equipment, including scrubbers, precipitators, fans and pumps.
Many of its most common uses involve exposure to seawater, where a Pitting Resistance Equivalent Number (PREN) greater than 40 indicates excellent pitting resistance, even in contaminated or brackish water. Maritime, naval, subsea and oil and gas applications feature heavily, some of which are shown in our case studies.
We supply Ferralium® in several forms, including bars, plates, pipes and fittings, with complementary weld wire. All Ferralium® products are tested to confirm high integrity, a correct phase balance and the absence of sigma and other potentially damaging phases.