Alloy 625 Nickel-Base Superalloy (UNS N06625)


Alloy 625 is a nonmagnetic, corrosion and oxidation resistant nickel bas alloy. Its outstanding strength and toughness from cryogenic temperatures to 2000˚F are derived from the solid solution effects of niobium and molybdenum in a nickel-chromium matrix. The alloy has excellent fatigue strength and stress corrosion cracking resistance in halide environments. Alloy 625 maintains its corrosion resistance in most seawater applications and provides a high level of resistance in both oxidizing and reducing environments. Applications for this grade include heat shields, gas turbine ducting, chemical plant components and seawater-exposed equipment.

Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM B443*
Element Alloy 625
Carbon 0.10
Chromium 20.0-23.0
Nickel 58.0 min
Molybdenum 8.0-10.0
Iron 5.0
Cobalt 1.0
Manganese 0.50
Silicon 0.50
Aluminum 0.40
Titanium 0.40
Phosphorus 0.015
Sulfur 0.015
Niobium + Tantalum 3.15-4.15
* Maximum, unless range is indicated
Mechanical Properties
Mechanical property requirements for Alloy 625 cold rolled sheet and strip product as specified in ASTM B443
Property Grade 1
(Annealed 1600˚F min)
Grade 2
(Solution Annealed 2000˚F min)
Yield Strength, min. (ksi) 60


Tensile Strength, min. (ksi) 120 100
Elongation, min. (%) 30 30
Physical Properties
Physical properties for Alloy 625
Property AISI 1008 Data
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 5.7
Specific Heat, Btu/lb ˚F 0.098
Electrical Resistivity, Microohm-in 50.8
Typical standards for Alloy 625
Alloy 625
AMS 5599

Data are typical, are provided for informational purposes, and should not be construed as maximum or minimum values for specification or for final design, or for a particular use or application. The data may be revised anytime without notice. We make no representation or warranty as to its accuracy and assume no duty to update. Actual data on any particular product or material may vary from those shown herein.  © 2014 RMP Inc. All rights reserved.