Alloy 31 (UNS N08031 / W.Nr. 1.4562)

Alloy 31 (UNS N08031 / W.Nr. 1.4562) is an iron-nickel-chromium-molybdenum alloy with nitrogen and copper additions which has hybridized properties of austenitic super stainless steels and regular nickel alloys. Alloy 31 has exceptional corrosion resistance to alkaline & halide-containing media, sulfuric acid, phosphoric acid, chlorine dioxide media, nitric acid as well as reducing & oxidizing medias. It is widely used in offshore & marine industries, chemical & petrochemical processing, pharmaceutical piping, oil and gas extraction, and ore digestion plants. Especially, Alloy 31 can be used for the fabrication of pressure vessels which may endure a wide temperature-range from cryogenic level to elevated temperatures(-196°C to 550 °C).

Equivalent Grades

Nicrofer 3127 hMoNS1404Alloy 31N08031X1NiCrMoCu 32-28-71.4562

Chemical Composition, %

Alloy 31≤0.015≤0.30≤2.00≤0.02≤0.01026.0-28.030.0-32.06.0-7.01.0-1.40.15-0.25Bal

Typical Physical and Mechanical Properties (RT, Annealed)

Density, g/cm3Melting Point, ℃Tensile Strength, MPaYield Strength, MPaELongation, %Hardness, HRB

Available Products and Specifications

Rod, Bar, Wire and ForgingsASTM B581, ASTM B649, ASME SB581, ASME SB649
Plate, Sheet and StripASTM B625, ASME SB625
Pipe and Tube
Welding Product
OthersAPI 5LD


  • Outstanding corrosion resistance in alkaline and acidic halide-containing media
  • Excellent resistance to sulfuric acid, even in highly concentrated form
  • Excellent resistance to corrosion and erosion in phosphoric acid media
  • Outstanding resistance to surface corrosion and local corrosion in chlorine dioxide bleaching plants in paper production
  • Excellent resistance in reducing and oxidizing media as well as in boiling azeotropic nitric acid
  • Good workability and weldability


  • Components for flue gas desulfurization (FGD) plants
  • Plants for the production of phosphoric acid via the wet digestion process
  • Pipes and heat exchangers for sulfuric acids contaminated with chlorides
  • Pipes containing ocean water and brackish water, condensers and chillers
  • Pickling plants for sulfuric acid as well as nitric-hydrofluoric acid
  • Treatment of sulfuric acids from waste
  • Evaporation and crystallization of salts
  • Components for the cellulose and paper industry
  • Digestion of ores, e.g. in HIPAL (high-pressure acid leach) plants for the digestion of laterite ores
  • Mineral oil production and refineries
  • Organic acids and ester synthesis
  • Fine chemicals
  • Strain-hardened transport and feed pipes as well as slicklines, wirelines and flowlines in the transport of oil and gas