What is the difference between N08825 and N06625?
Nickel alloy 625 is a nickel-chromium-molybdenum-niobium alloy material. The main component nickel content is at least 58%. It is also known as Inconel 625 or UNS NO6625. The pipe standard is ASTM B444, and the plate and coil standard is ASTM B443. Other chemical compositions are 20% to 23% chromium, 3.15% to 4.15% niobium + tantalum, 8.0% to 10.0% molybdenum, 1.0% niobium and cobalt allowed (if determined), and 5.0% iron.
Density 8.4 g/cm3, melting point 1290-1350℃. It has excellent corrosion resistance to inorganic acids and various corrosive media in oxidizing and reducing environments.
Inconel 625 alloy / Inconel 625 / UNS N06625 characteristics
Inconel 625 alloy is a non-magnetic, corrosion-resistant and oxidation-resistant nickel-chromium-based solid solution strengthened deformation high-temperature alloy.
A solid solution strengthened nickel base wrought high temperature alloy with molybdenum and niobium as the primary strengthening elements. The high strength of Inconel 625 is due to the hardening combination of molybdenum and niobium in the nickel-chromium matrix of the alloy. The addition of molybdenum works with niobium to harden the alloy matrix, providing high strength without the need for intensive heat treatment.
Inconel 625 is extremely resistant to a wide range of extremely severe corrosive environments, including corrosion, high temperature effects such as oxidation and carburization. 625 has excellent strength and toughness at elevated temperatures from cryogenic to 2000°F (1093°C) due to the solid solution of refractory Co and Mo in the nickel-chromium matrix.
Inconel 625 Composite Pipe Liner/Nickel Alloy 625 Weld Overlay
Inconel 625 material can be clad or lined on high strength carbon steel pipes such as API 5L X60, X65, X70, which includes outer parent pipe carbon steel to provide strength, and inner material clad or lined Inconel 625 to provide high corrosion resistance in various environments including marine, airspace, chemical plants and petrochemical industries.
Cladding or lining the inside of carbon steel pipe with Inconel alloy 625 material has been a popular choice to solve corrosion problems and save a lot of costs.
Inconel 625 Advantages
High tensile strength and high corrosion fatigue performance;
High oxidation resistance at high temperatures up to 1050C.
Good processing and welding performance;
Excellent corrosion resistance and oxidation resistance;
Resistant to stress corrosion in salt spray atmosphere;
Excellent resistance to pitting, crevice corrosion and intergranular corrosion;
Excellent mechanical properties at both very low and very high temperatures;
Almost completely unaffected by stress corrosion cracking caused by chlorides;
Good corrosion resistance to acids such as nitric acid, phosphoric acid, sulfuric acid and hydrochloric acid, as well as alkalis, and can manufacture thin structural parts with high heat transfer.
Nickel alloy 625 / Inconel 625 / UNS N06625 has very low corrosion rates in both marine and non-marine environments, good seawater corrosion resistance, corrosion resistance to various salt solutions, good corrosion resistance to HNO3 phosphoric acid, and considerable corrosion resistance to HCl and low-concentration sulfuric acid heated below the boiling point. The aging hardening phenomenon produced by the alloy after long-term use at 550-700℃ will cause the plasticity of N06625/No6625 alloy to decrease. and stress corrosion cracking resistance to chloride ions – making it an excellent choice for seawater and aerospace applications.
Applications
Aerospace
Offshore
Nuclear reactors
Boilers and furnaces
Engine components
Components exposed to seawater and high mechanical stresses.
Oil and gas production where hydrogen sulfide and elemental sulfur are present at temperatures exceeding 150°C.
Components exposed to flue gases or flue gas desulfurization plants.
Flare stacks on offshore oil platforms.
Hydrocarbon processing in tar sands and oil shale recovery projects.
Pollution control equipment
Manufacturing Inconel 625 Composite Pipe – CRA lined and composite pipe made from carbon steel pipe by mechanical lining or weld overlay process
Components commonly used for this alloy are springs, seals, submersible control bellows, cable connectors, fasteners, bends and marine instrument components. A wide range of plates, bars, tubes and forgings are available. The machinability of nickel alloys is typical of them, the material is easy to form and can be welded by a variety of techniques.
Inconel 625 alloy chemical composition:
Nickel 58% minimum
Chromium 20% to 23%
Molybdenum 8% to 10%
Iron 5.0% maximum
Carbon 0.10% maximum
Manganese 0.50% maximum
Silicon 0.50% maximum
Phosphorus 0.015% maximum
Sulfur 0.015% maximum
Aluminum 0.40% maximum
Titanium 0.40% maximum
Niobium + Tantalum 3.15% to 4.15%
