Originally developed for high pressure steam lines in power plants in the 1960s, it quickly became apparent that Alloy 625 could handle extreme corrosion and oxidation from harsh environments. Referred to as a "superalloy" due to its ability to withstand high temperatures, stress, and corrosion, it features molybdenum, chromium, and niobium, which confer additional creep strength against stressors like high temperatures and other harsh conditions that could deform less resistant alloys over time.

Initially touted for its creep strength at high temperatures, Alloy 625 proved to remain nearly corrosion-free even at ambient to low temperatures in harsh environments such as seawater and chemical processing of acids and salts. It is virtually immune to chloride-ion stress cracking, thanks to its high nickel content, and has been employed in a variety of applications including propellers and propulsion systems as well as wires used in cable sheathing for marine environments. Its high ductility makes it ideal for fasteners like hex bolts in underwater applications. Owing to its ease of weldability, Alloy 625 has been used in weld overlays to improve the strength and corrosion resistance of base metals, such as those found in boiler tubes or petrochemical equipment like wellheads. Cheaper, thicker layers of base materials like steel alloys can be weld cladded with Alloy 625 even at economical dilutions with the right technique, offering significant strength and protection against corrosion.

One method of processing Alloy 625 is through Vacuum Induction Melting (VIM), which uses a strong electric current to melt the alloy in a vacuum. This process allows for careful control of the melting, resulting in a more uniform microstructure with a fine grain size. Alloy 625 that has undergone this process is known as 625 LCF (Low Cycle Fatigue), which has better thermal stability and improved resistance to mechanical fatigue, making it suitable for applications like bellows that undergo cyclic temperature conditions.

While not as widely utilized in the aerospace industry as some newer alloys, Alloy 625 continues to find new applications due to its outstanding corrosion resistance and strength. It has been used in solar power stations, the automotive industry, and even in aerospace applications where advanced manufacturing processes like selective laser melting (SLM) are employed to produce complex, high-integrity parts quickly and at reduced costs.