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
Trademark | GB | GOST | ASTM | UNS | DIN | W.Nr. | NF | BS | JIS | SS |
Nicrofer 3127 hMo | NS1404 | – | Alloy 31 | N08031 | X1NiCrMoCu 32-28-7 | 1.4562 | – | – | – | – |
Chemical Composition, %
Alloy | C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N | Fe |
Alloy 31 | ≤0.015 | ≤0.30 | ≤2.00 | ≤0.02 | ≤0.010 | 26.0-28.0 | 30.0-32.0 | 6.0-7.0 | 1.0-1.4 | 0.15-0.25 | Bal |
Typical Physical and Mechanical Properties (RT, Annealed)
Density, g/cm3 | Melting Point, ℃ | Tensile Strength, MPa | Yield Strength, MPa | ELongation, % | Hardness, HRB |
8.05 | 1330-1370 | ≥650 | ≥280 | ≥40 | / |
Available Products and Specifications
Rod, Bar, Wire and Forgings | ASTM B581, ASTM B649, ASME SB581, ASME SB649 |
Plate, Sheet and Strip | ASTM B625, ASME SB625 |
Pipe and Tube | – |
Welding Product | – |
Others | API 5LD |
Features
- 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
Applications
- 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