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.
Alloy 625 can be used for parts requiring both corrosion and oxidation resistance up to 2000ºF (1093˚C). AMS 5666 requires a minimum yield strength of 60,000 psi at room temperature for bars under 4 inches in diameter. Mechanical properties for bars 4 inches in diameter and larger are to be agreed upon by purchaser and vendor. 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).
Nickel Alloy 625 Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM B446*
| Carbon | 0.10 | Silicon | 0.50 |
| Chromium | 20.00-23.00 | Phosporous | 0.015 |
| Nickel | 58.00 min | Sulfur | 0.015 |
| Molybdenum | 8.00-10.00 | Aluminum | 0.40 |
| Iron | 5.00 | Columbium+Tantalum | 3.15-4.15 |
| Titanium | 0.40 | Cobalt | 1.00 |
| Manganese | 0.50 |
*Maximum, unless range is indicated
Nickel Alloy 625 Physical Properties
| Density, lb/in3 | 0.305 |
| Modulus of Elasticity, psi | 29.8 x 106 |
| Coefficient of Thermal Expansion, 68-212˚F, /˚F | 7.1 x 10-6 |
| Thermal Conductivity, Btu/ft hr ˚F | 6.3 |
| Specific Heat, Btu/lb ˚F | 0.098 |
| Electrical Resistivity, Microhm-in | 50.7 |
Nickel Alloy 625 Mechanical Properties
Mechanical property requirements for heat treated bar product as specified in ASTM B446
| Property | Grade 1 | Grade 2 | Grade 3 |
| Yield Strength, min. (ksi) | 60 | 50 | 40 |
| Tensile Strength, min. (ksi) | 120 | 110 | 100 |
| Elongation, min. (%) | 30 | 25 | 30 |
Nickel Alloy 625 Standards
| ASTM B446 |
| ASME SB446 |
| AMS 5666 |
| AMS 5665 |
Your Source for Nickel Alloy 625
At Double Eagle Alloys, we supply Nickel Alloy 625 in long bar, flanges, pipe, sheet, gaskets, fittings and header plugs engineered for these demanding services. Contact our team to learn how Nickel Alloy 625 can support long-term performance and reliability.
Questions? We’d love to help. Contact us today to discuss your needs or to check current availability.
Contact Us
Data shown are typical and provided for informational purposes only. Values should not be considered minimums or maximums for specification or final design. Actual product data may vary, and information may be revised without notice.