Applications of Corrosion resistant Nickel based alloys
Due to its property to resist corrosion, Nickel is specifically useful for maintaining product purity in handling foods, synthetic fibers, caustic alkalies and in structural applications that critically demand corrosion resistance. Nickel is a general purpose metal. The common applications of Nickel 200 are food processing system, chemical shipping drums, electrical and electronic components, aerospace and missile parts, caustic handling system, pipes and transducers. Nickel 201 is utilized in coinage, plater bars and in combustion boats.
Nickel-Copper alloys are featured by high strength, weldability, outstanding corrosion resistance and hardness over the extensive temperature limit. They keep clean and wettable surface in fact subsequent to prolong exposure in wet hydrogen. Monel alloy K-500 offers better properties than alloy 400 after cold processing before aging treatment. It sustains its strength over the large temperature limit up to 649oC or 1200oF and it is a strong, hard and ductile material even at temperature below to -253oC or -423oF. It has nominal permeability and is nonmagnetic at -134oC or -210oF. Monel K500 shows minor corrosion rates in the extensive range of conditions. The common applications are electronic parts, springs, oil-well drill collars and equipments, scrapers, doctor blades, pump shafts and impellers. Monel alloys are significant for use in the corrosive chemicals including hydrofluoric acid and severe marine conditions.
Nickel-chromium-iron alloys are significant for elevated temperature oxidizing conditions. Inconel 600 is oxidation resistant up to 1177oC or 2150oF and keeps high strength and workability. It is hardened and strengthened through cold processing. It keeps its strength, ductility and hardness at cryogenic and high temperatures. Due to its resistance to chloride ion stress cracking and corrosion by high purity water, it is utilized in nuclear reactors. Alloy is constructed in the exacting specifications for use in furnace muffles, electronic parts, heat exchanger tubes, chemical and food processing system, carburizing baskets, fixtures, rotors, reactor control rods, nuclear reactor parts, springs and water pipes. Inconel alloy 600 is one of the standard heat resistant and high temperature performance alloys that are still in use.
Inconel 601 describes nominal oxidizing and scaling rates at high temperatures about 1093oC or 2000oF. High content of chromium prevents oxidizing, carburizing and sulfur attacks. Oxidation attack prevention is further improved by addition of aluminum. It is used in thermocouple security tubes, furnace muffles, retorts, strand annealing tubes, heat treating baskets and fixtures, radiant furnace tubes etc.
Inconel alloy 706 is a precipitation hardenable alloy with properties comparable to Inconel 718, however it offers enhanced machining competence. Suitable resistance to oxidation and other types of attack over the large temperature limits and conditions. Supreme resistance to postweld strain age fracture. It is used in gas turbine parts and others that need outstanding mechanical strength with fine machining and welding properties.
Inconel alloy 718 offers service range from -253oC or -423oF to 704oF or 1300oF. High fatigue strength and stress cracking resistance up to 704oC, prevents oxidation up to 982oC. Nominal response to age hardening makes alloy 718 to be welded and annealed without immediate hardening if it is not slightly quenched. It is widely used in jet engine parts, pumps, rocket motors, thrust reversers and spacecrafts.
Inconel X750 offers exceptional creeping strength up to 816oC or 1500oF. It is primarily made for use in gas turbines and jet engines and has been used in the other applications for its suitable set of characteristics. High relaxation resistance makes it fit for springs performing up to 649oC or 1200oF. It also keeps good strength and ductility at small temperatures below to -253oC or -423oF. It also prevents chloride ion stress corrosion cracking in the fully age hardened conditions. Used in aviation and industrial gas turbine components, springs for steam applications, nuclear reactors, vacuum enclosures, heat processing fixtures, extrusion dies, aircraft sheet and forming apparatus.
Nickel-iron-chromium alloys are recommended for use in the high temperature conditions that need to stop oxidation or corrosion attack.
Incoloy 800 is recommended for its resistance to scaling, general corrosion and SCC. It is used in heat processing system, heat exchangers in chemical, petrochemical and nuclear plants, specifically where resistance to SCC is needed. Broadly used in sheathing on electric heating materials.
Incoloy 800H is used in the several applications that involve prolong exposure of operation systems at the high temperatures or in the attacking conditions.
Incoloy 825 is resistant to reducing acids, oxidizing chemicals, pitting and intergranular corrosion when heated in the critically susceptible temperature range. It is resistant to attack in sulfuric acid, phosphoric acid and seawater. The general applications include phosphoric acid evaporators, pickling tank heater, pickling hooks and units, chemical treatment equipment, used nuclear fuel element recovery, propeller shafts, tank trucks and oil-country cold worked tubular.
Incoloy 825 offers increased resistance to reducing acids and localized attack in chlorides.
Nickel-iron alloys offer constant coefficient of expansion to a temperature below the Curie temperature. Nilo 36 is used as tooling for curing composite airframe parts. Nilo 42 is used in semiconductor lead frames and glass sealing applications. Ni Span C902 is a precipitation hardenable alloy with similar thermal expansion properties to Nilo 42 however it has unlike coefficients of expansion.
Nickel-Iron-Molybdenum alloys offer supreme oxidation resistance and keep significant strength up to 1093oC or 2000oF.
Hastelloy X is recommended for high temperature applications up to 1204oC or 2200oF, it is used in furnace hardware that are exposed to oxidizing, reducing and neutral conditions, aircraft jet engine tail pipes and combustion cans and afterburner parts.
Hastelloy C offers excellent high temperature strength, it is used in chemical, petrochemical and oil refinery plants, aircraft jet engine and heat treating systems.
Hastelloy C-276 is used in solution treated condition; no postwelding heat processing is required for chemical processing unit. General applications include chemical and petrochemical processing unit, aircraft jet engine and deep sour gas wells. Hastelloy C276 is a modified form of Hastelloy C containing nominal magnitudes of carbon and silicon to prevent carbide precipitation in the heat affected region of weldments. It is non-age hardenable and is utilized in the solution treated form.
Inconel 617 is a popular material for gas turbine aircraft engines and other applications including exposure to extreme temperatures like steam generator tubing and pressure vessels for high temperature gas cooled nuclear reactors.
Hastelloy G is a non-age hardenable alloy that is resistant to pitting and stress corrosion cracking with general applications including paper and pulp processing, phosphate fertilizer and synthetic fiber processing.