iron nickel chromium alloy is a high-temperature and corrosion-resistant material that is available in various forms. These include bar, ingot, wire, sheet, and foil.
These nickel-chromium-iron alloys are used for a wide variety of applications in the nuclear, chemical, and petrochemical industries. These materials are particularly suitable for applications with oxidizing atmospheres, where the presence of iron can help prevent internal oxidation and embrittlement.
Common grades of nickel-chromium-iron alloys include INCOLOY 800H and INCOLOY 800HT. These grades are low nickel versions of the INCONEL alloy range that have a significant iron content, making them more economical solutions for use in corrosive and high-temperature environments.
These alloys offer excellent corrosion resistance for both general and localized conditions in a wide range of corrosive environments. They are resistant to pitting, crevice corrosion, chloride-ion stress corrosion cracking, and reducing environments containing aggressive sulfuric and phosphoric acids.
The composition of these alloys can be modified to optimise properties for specific applications. This is particularly important in applications with fuel ashes or deposits of alkali metal salts such as sulphates.
The optimum chromium additions for these alloys are 20% chromium and higher. This level of chromium increases the electrical resistivity, and can be optimised for intermittent usages such as heating elements. It is also suitable for continuous usages, especially where the ash or salt is not subject to frequent changes in temperature. The composition of these alloys can also be modified to optimise the ductility for wire drawing.