Alloy 690 • UNS N06690 • WNR 2.4642

Alloy 690 is a high-chromium nickel alloy having excellent resistance to many corrosive aqueous media and hightemperature atmospheres. The alloy’s high chromium content gives it excellent resistance to caturisation, metal dusting, oxidation and sulfidation at high temperature. In addition to its corrosion resistance, alloy 690 has high strength, good metallurgical stability, and favorable fabrication characteristics.

Available tube product forms

Typical Applications

  • Heat exchangers
  • Steam Generators
  • High temperature applications exposed to caustic solutions

Typical manufacturing specifications

  • ASTM B167
  • Also individual customer specifications.

Industries predominantly using this grade            

Technical Data

Mechanical Properties

Temper Annealed
Tensile Rm 86 ksi (min)
Tensile Rm 590 MPa (min)
R.p. 0.2% Yield 35 ksi (min)
R.p. 0.2% Yield 240 MPa (min)
Elongation (2” or 4D gl) ≥30 % (min)


Physical Properties (Room Temperature)

Specific Heat (0-100°C) 450 J.kg-1.°K-1
Thermal Conductivity 13.5 W.m -1.°K-1
Thermal Expansion 14 mm/m/°C
Modulus Elasticity 211 GPa
Electrical Resistivity 1.26 μohm/cm
Density 8.2 g/cm3


Chemical Composition (% by weight)

Element Min Max
C - 0.05
Si - 0.5
Mn - 0.5
P - 0.02
S - 0.015
Al - 0.5
Cr 27 31
Cu - 0.5
Fe 7 11
Ti - 0.5
Ni Balance
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