Alloy 255 is a 25% chromium super duplex stainless steel. Alloy 255 contains a copper addition which provides it with greater resistance to sulfuric acid than other super duplex grades. Because of its duplex structure alloy 255 also offers excellent strength characteristics and resistance to chloride ion stress corrosion cracking.


255 Pipe, 255 Plate, 255 Round Bar, 255 Sheet

Common Trade Names

Ferralium® 255, Alloy 255


  • High strength
  • Chloride stress corrosion cracking resistance
  • Lower coefficient of thermal expansion than austenitic stainlesses
  • Good sulfuric acid resistance


  • Pulp and paper
  • Chemical process
  • Flue-gas desulfurization
  • Copper smelting
  • Mixers and pumps