Alloy 31 Nicrofer 3127hMo FeNiCrMo Alloy with Addition of Nitrogen

Alloy 31 is an iron-nickel-chromium-molybdenum alloy with the addition of nitrogen. The alloy closes the gap between high alloyed austenitic special stainless steels and nickel alloys. Alloy 31 has proven itself to be suitable particularly in the chemical and petrochemical industries, in ore digestion plants, in environmental
and marine engineering as well as in oil and gas extraction.

Chemical composition

Advantages of Alloy 31

• 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
• VdTÜV-certification for pressure vessels with operating temperatures from -196 to 550 °C (-320.8 to 1,022 °F)
• Certification according to ISO 15156/NACE MR 0175 up to level VI for acid gas applications in the oil and gas
• industry
• ASME approval for pressure vessels up to 800 °F (427 °C)

Applications of Alloy 31

• Components for flue gas desulfurization 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