Inconel 625 is different from many other Inconel alloys; its composition differs exponentially. In addition to the standard nickel-chromium-iron blend, Inconel 625 contains amounts of molybdenum and columbium. The combination of molybdenum and columbium alloyed together produces a metal that is naturally strong. It does not have to undergo heat treatment, like many other metals, to achieve high levels of strength. It also has the corrosion resistance common in nickel alloys, and is particularly well suited for crevices. Because of this, Inconel 625’s properties are often utilized for marine and aerospace engineering, along with welding.
Its unique composition and properties make Inconel 625 excellent in both acidic and alkaline environments, along with those that are caustic and aqueous. Sea water environments are a common application as well, along with those that experience high stress. Inconel 625 has been known to replace Type 304 Stainless Steel due to its increased strength and fatigue resistance.
The metal is best worked under a combination of hot and cold practices, as it work-hardens rapidly.