Various alloys of iron-nickel-chromium have been tested in laboratory and field conditions for their corrosion resistance and mechanical properties. In preliminary studies, aluminum has been found to improve corrosion resistance in sulfurous environments. Several alloys have been tested for their resistance to mechanical wear, corrosion and creep rupture strength.
Nickel-iron alloys are used in applications such as electric resistance heating elements and electronic devices. They can also be used as forming materials. These alloys are supplied in a fine-grain condition or in a mill-annealed condition. The composition of these alloys must be appropriate for the application.
Several alloys of iron-nickel-chromium-aluminum have been tested for their corrosion resistance and mechanical properties. The alloys were tested under oxidizing, sulfidizing, carburizing and thermal environments.
A high chromium nickel alloy is a desirable alloy for high-level waste storage. It is also useful in fast breeder reactor claddings. However, the alloys are prone to localized corrosion. In addition, they may have a reduced fracture toughness and creep rupture strength over time.
Low-nickel alloys have higher initial permeability than 79% Ni alloys. They are useful for measuring instruments that require magnetic temperature compensation. They also have a higher maximum permeability.
A nickel-iron-chromium alloy has an age-hardenable crystal structure. It has a maximum content of 40 to 50% nickel, 0.3 to 0.75% silicon and 0.1 to 5% aluminum. It also has a maximum oxidation resistance of -35 percent.
A low-nickel alloy is useful for measuring instruments that require magnetic temperature compensation. It has a higher maximum permeability than 79% Ni alloys. It also has a higher saturation induction.
