ATI 625™ alloy (UNS Designation N06625) is an austenitic nickel-base superalloy possessing excellent resistance to oxidation and corrosion over a broad range of corrosive conditions, including jet engine environments and in many other aerospace and chemical process applications. The alloy has outstanding strength and toughness at temperatures ranging from cryogenic temperature to 2000°F (1093°C). ATI 625™ alloy also has exceptional fatigue resistance.

ATI 625™ alloy derives its strength from the solid solution strengthening effects of molybdenum and columbium on the nickel-chromium matrix. These elements also contribute to the alloy's outstanding corrosion resistance. Although the alloy was developed for high temperature strength, its highly alloyed composition provides a high level of general corrosion resistance to a wide range of oxidizing and non- oxidizing environments. The levels of chromium and molybdenum provide excellent resistance to chloride ion pitting and the high level of nickel provides resistance to chloride stress corrosion cracking.

The material possesses a high degree of formability and shows better weldability than many highly alloyed nickel-base alloys. The alloy is resistant to intergranular corrosion even in the welded condition.

ATI 625™ alloy can be produced by vacuum induction melting or AOD refining. Consumable electrode remelting procedures may be used to further refine the material.