Nickel Alloy 625 is used both for its high strength and outstanding aqueous corrosion resistance. The strength of Nickel Alloy 625 is primarily a solid solution effect from molybdenum and columbium. Nickel Alloy 625 has excellent weldability. The matching filler metals are often used for dissimilar metal joining and to weld the aqueous corrosion alloy AL­6XN®..

Features of Nickel Alloy 625

The key features of Nickel Alloy 625 include:

  • Outstanding resistance to chloride pitting and crevice corrosion cracking
  • Immune to chloride ion stress corrosion cracking
  • Resistant to caustics
  • Resistant to seawater, in both flowing and stagnant conditions, and under fouling

Applications of Nickel Alloy 625

Typical Applications for the Nickel Alloy 625 include:

  • Chemical process equipment handling mixed acids both oxidizing and reducing
  • Flue gas desulfurization scrubbers
  • Evaporators for wet­process phosphoric acid containing H2SO4, HF and ferric salts
  • Weld Overlay

Chemical Composition

The following table shows the chemical composition of Nickel Alloy 625

   Minimum %  Maximum %
Chromium   20.0  23.0
Nickel 58.0 Balance
Molybdenum 8.0 10.0
Cobalt 0.0 1.0
Columbium + Tantalum 3.15 4.15
Aluminium   0.4
Titanium   0.4
Carbon   0.1
Iron   5.0
Manganese   0.5 
Silicon   0.5 
Phosphorus   0.015
Sulfur   0.015

Physical Properties

Density 0.305 lbs/inch3
Melting Range 23502 - 2460oF