Alloy 625 is an austenitic nickel-chromium-molybdenum-niobium alloy possessing a rare combination of outstanding corrosion resistance coupled with high strength from cryogenic temperatures to 1800°F (982°C).

The strength of Alloy 625 is derived from the solid-solution hardening of the nickel-chromium matrix by the presence of molybdenum and niobium. Therefore, precipitation-hardening treatments are not required.

The chemical composition of Alloy 625 is also responsible for its outstanding corrosion resistance in a variety of severe operating environments along with resistance to oxidation and carburization in high temperature service. The alloy is resistant to pitting, crevice corrosion, impingement corrosion, intergranular attack and is almost immune to chloride stress corrosion cracking.

Alloy 625 can be easily welded and processed by standard shop fabrication practices.

Applications

• Aerospace Components — bellows and expansion joints, ducting systems, jet engine exhaust systems, engine thrust-reversers, turbine shroud rings

• Air Pollution Control — chimney liners, dampers, flue gas desulfurization (FGD) components

• Chemical Processing — equipment handling both oxidizing and reducing acids, super-phosphoric acid production

• Marine Service — steam line bellows, Navy ship exhaust systems, submarine auxiliary propulsion systems

• Nuclear Industry — reactor core and control rod components, waste reprocessing equipment

• Offshore Oil and Gas Production — waste flare gas stacks, piping systems, riser sheathing, sour gas piping and tubing

• Petroleum Refining — waste flare gas stacks

• Waste Treatment — waste incineration components