Alloy 625 • UNS N06625 • WNR 2.4856

Alloy 625 is a nickel-chromium alloy used for its high strength, excellent fabricability and outstanding corrosion resistance. Service temperatures can range from cryogenic to 980°C (1800°F). Alloy 625 strength is derived from the solid solution strengthening effect of molybdenium and niobium on its nickel-chromium matrix.

Thus precipitation-hardening treatments are not required. This combination of elements also is responsible for superior resistance to a wide range of corrosive environments of unusual severity as well as to high-temperature effects such as oxidation and carburization.

Available tube product forms

Typical Applications

Typical manufacturing specifications

  • ASTM B444
  • AMS 5581
  • BS 3074
  • Also individual customer specifications.

Industries predominantly using this grade            

Technical Data

Mechanical Properties

Temper Annealed (Grade1) Solution-treated (Grade 2)
Tensile Rm 120 ksi (min) 100 ksi (min)
Tensile Rm 827 MPa (min) 690 MPa (min)
R.p. 0.2% Yield 60 ksi (min) 40 ksi (min)
R.p. 0.2% Yield 414 MPa (min) 276 MPa (min)
Elongation (2” or 4D gl) 30 % (min) 30 % (min)


Physical Properties (Room Temperature)

Specific Heat (0-100°C) 460 J.kg-1.°K-1
Thermal Conductivity 14.8 W.m -1.°K-1
Thermal Expansion 12.4 mm/m/°C
Modulus Elasticity 207 GPa
Electrical Resistivity 10.3 μohm/cm
Density 8.42 g/cm3


Chemical Composition (% by weight)

Element Min Max
C - 0.1
Si - 0.5
Mn - 0.5
P - 0.015
S - 0.015
Al - 0.4
Cr 20 23
Cu 1 1.4
Fe - 5
Mo 8 10
Nb 3.15 4.15
Ni Balance
Ti - 0.4
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