Nickel 60% Chromium 22% Molybdenum 9% Columbium plus Tantalum 4%
Standard Inventory Specifications
• AMS 5599
• ASTM B 443
• Predominantly produced by AOD-ESR melt. Hot worked, solution treated (annealed), then descaled.
Alloy 625 is an austenitic nickel-base superalloy with excellent resistance to oxidation and corrosion over a broad range of conditions, including jet engine and chemical process applications. The outstanding strength and toughness of Alloy 625, at temperatures ranging from cryogenic to 2000°F (1093°C), are derived primarily from the solid solution strengthening of columbium and molybdenum in a nickel-chromium matrix.
Non-magnetic. Alloy 625 can be used for parts requiring both corrosion and oxidation resistance up to 2000ºF (1093°C). This alloy is exceptionally resistant to crevice corrosion and stress corrosion cracking and to chemical attack in both highly oxidizing to moderately reducing conditions. Alloy 625 is virtually immune to corrosion in marine environments and is used extensively in the hot section of jet engines and in high temperature corrosive environments in the chemical processing industry. The alloy has outstanding resistance to creep and stress rupture up to 1200ºF (649°C), and oxidation and scaling resistance up to 2000ºF (1093°C).
Hardness of Aerodyne stock is typically 185 BHN. The microstructure remains austenitic at both elevated and low temperatures. Alloy 625 cannot be hardened by heat treatment but can be hardened by cold working. During cold working, Alloy 625 work hardens more rapidly than austenitic stainless steels.
RATING: 16% of B-1112
TYPICAL STOCK REMOVAL RATE: 25 surface feet/minute with high speed tools. 100 surface feet/minute with carbide.
Use relatively heavy cuts and low speeds to minimize surface work hardening
Alloy 625 can be welded by most customary techniques, such as inert gas tungsten arc (TIG), gas metal arc welding (GMAW), plasma, electron beam, submerged arc and resistance welding. If excessive heat input and oxidation are avoided during welding, Alloy 625 can be put into service without any subsequent postweld thermal treatments.
Density: 0.305 lbs/in3, 8.44 g/cm3