Nickel AlloysAMS 5666 (Alloy 625) Bar & Forgings

A nickel-chromium-molybdenum-niobium alloy with excellent resistance to a variety of corrosive media.

An American aerospace standard for NiCr22Mo9Nb4, nickel alloy 625. The high tensile creep and rupture strength; outstanding fatigue and thermal-fatigue strength; oxidation resistance and excellent weldability/brazeability are the properties of alloy 625 that make it of interest within aerospace applications.

Alloy 625 is a nickel-chromium based alloy with min 58% nickel which gains its stiffening effect through additions of molybdenum and niobium thus eliminating the need for this alloy to be aged.

It has superior resistance to a wide range of corrosive environments as well as the high temperature effects of oxidation and carburisation.

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Related Specifications

  • ASTM B446-03 (2014) UNS N06625
  • NACE MR0175/ISO 15156-3


Chemical Composition


  • Aircraft engine components


  • Exceptional resistance to pitting, crevice corrosion, erosion and intergranular corosion
  • Immunity to chloride-induced stress corrosion cracking
  • Good resistance to mineral acids such as nitric, phosphoric, sulfuric, and hydrochloric acids
  • Good resistance to alkalis and organic acids
  • Good mechanical properties
  • Excellent weldability
  • Low magnetic permeability
  • Non magnetic and spark resistant

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