1.4507 is the Werkstoff number for the super duplex stainless steel most commonly known as Ferralium® 255. Werkstoff numbers were developed by the German standards body DIN; the word translates roughly as "material".
Ferralium® is the original super duplex stainless steel. We developed it through the 1960s and submitted a patent application in 1967. At that time Langley Alloys operated a foundry, forge, rolling mills, laboratory and valve-manufacturing business, so trial alloys were used in our own products. When the patent was granted in 1969, the developmental "Langalloy 40R" product was re-branded as Ferralium®.
Super duplex stainless steels combine austenitic and ferritic microstructures, which gives them an optimum set of physical and mechanical properties: high strength, excellent resistance to corrosion and stress corrosion cracking, and strong cost-effectiveness compared with more highly alloyed alternatives.
Compared with other super duplex stainless steels, Ferralium® 255 has the greatest yield strength (85ksi / 586N/mm2), allowing thinner sections for the same functional performance. Its 2% copper addition gives superior resistance to sulphuric, nitric and phosphoric acid, while the high chromium level ensures long-term performance in seawater.
We stock Ferralium® 255 (1.4507, F61, X2CrniMoCuN, UNS S32550) as solid bars between 1/2" (12.7mm) and 14" (355.6mm) diameter. Our stock is certified to NACE MR0175 / ISO 15156-3 and produced in a Norsok-qualified mill.