Incoloy alloy 925 (UNS N09925) with the additions of molybdenum, copper, titanium, and aluminium is an age hardenable nickel-iron-chromium alloy, providing a combination of high strength and excellent corrosion resistance. Sufficient nickel content provides protection against chloride-ion stress-corrosion cracking whilst in conjuncton with the added molybdenum and copper, resistance to reducing chemicals is enjoyed. Molybdenum additionally aids in resistance to pitting and crevice corrosion, while chromium offers resistance to oxidizing environments. During heat treatment, a strengthening reaction is caused by the addition of titanium and aluminium.

Applications requiring a combination of high strength and corrosion resistance may consider Incoloy alloy 925. Resistance to sulfide stress cracking and stress-corrosion cracking in “sour” crude oil and natural gas environments means that it is used for down-hole and surface gas-well components as well as finding uses in marine and pump shafts or high-strength piping systems.

• 1. Chemical Composition Requirement

  The Chemical Composition of Incoloy 925
  Nickel	42.0-46.0
  Chromium	19.5-22.5
  Iron	≥22.0
  Molybdenum	2.5-3.5
  Copper	1.5-3.0
  Titanium	1.9-2.4
  Alumium	0.1-0.5
  Manganese	≤1.00
  Silicon	≤0.50
  Niobium	≤0.50
  Carbon	≤0.03
  Sulfur	≤0.30

• 2. Mechanical Properties of Incoloy 925

  Tensile Strength, min.		Yield Strength, min.		Elongation, min.	Hardness, min.
  Mpa	ksi	Mpa	ksi	%	HRC
  1210	176	815	118	24	36.5

  3. Physical Properties of Incoloy 925

  Density	Melting Range		Specific Heat		Electrical Resistivity
  g/cm3	°F	°C	J/kg.k	Btu/lb. °F	µΩ·m
  8.08	2392-2490	1311-1366	435	0.104	1166

  4. Product Forms and Standards

  Product Form	Standard
  Rod, bar & Wire	ASTM B805
  Plate, sheet & strip	ASTM B872
  Seamless pipe and tube	ASTM B983
  Forging	ASTM B637