Alloy 945 / UNS N09945 is a nickel-based precipitation-hardening superalloy designed for extreme environments, combining high strength, excellent corrosion resistance and good processing properties. Its chemical composition is based on nickel, with chromium and molybdenum added to enhance corrosion resistance, especially against chloride stress corrosion cracking (SCC) and pitting; it also contains niobium and titanium as precipitation strengthening phases (such as γ' phase), supplemented by iron to reduce costs and aluminum to improve oxidation resistance. The alloy is precipitation strengthened by aging heat treatment, and the room temperature tensile strength can reach about 1100 MPa while maintaining high ductility (elongation of about 20%).

The outstanding characteristics of Alloy 945 / UNS N09945 include stability in acidic, high-salt and high-temperature environments, and are suitable for harsh scenarios such as oil and gas (such as downhole tools, valves), marine engineering and chemical equipment. It has also become one of the preferred materials for deep-sea drilling and high-pressure acidic environments. Typical applications include oil production pipes, fasteners and reactor components, balancing performance and economic requirements.