Nickel-chromium-molybdenum alloy material, also known as Inconel 625, is a nonmagnetic corrosive resistance alloy used in a wide variety of severely corrosive environments. Its outstanding corrosion resistance in acidic and alkaline environments is a result of its high nickel content. The chromium content also gives it superior oxidation and scaling resistance at elevated temperatures.
Common uses of Inconel 625 include aerospace, oil & gas and chemical processing equipment where exposure to hydrogen sulfide and elementary sulfur is present at elevated temperature and pressures. Other industrial applications include flare stacks, gas turbine engine ducting and combustion liners, furnace hardware, and chemical plant equipment.
Alloy 625 is a solid solution-treated nickel-chromium alloy that contains additions of molybdenum and niobium. The resulting alloy is highly resistant to pitting and crevice corrosion as well as other severe corrosive environments.
Its low-magnetic properties make it suitable for machining and its excellent strength and toughness at cryogenic temperatures (cryogenic to 1800degF / 982degC) give it the ability to resist cyclic heating and cooling cycles. It is a good choice for jet engine exhaust systems, propeller blades and heat exchangers.
Grade 1 is supplied annealed and can be welded using conventional arc welding techniques. To reduce residual stresses during fabrication, stress relieving is often performed at 1100degF - 1500degF (600degC - 815degC). For higher service temperaures, it may be subjected to a further stabilisation anneal (1800degF / 982degC) or solution annealing. The latter enables the maximum softness to be developed for cold rolling and drawing processes.