Alloy 825 (UNS N08825)


Alloy 825 is a nickel-iron-chromium alloy with additions of molybdenum, copper and titanium (NiCr21Mo), supplied in the hot worked and annealed condition. It achieves good mechanical properties from cryogenic to medium-high temperatures (5400C) and can be significantly strengthened through cold working.

The high nickel content ensures resistance to stress corrosion cracking, combined with molybdenum and copper to strongly resist reducing environments such as sulphuric and phosphoric acids, chromium to resist oxidising environments such as nitric acid, titanium to inhibit intergranular corrosion, and overall resistance to pitting and crevice corrosion.

Key Features:

  • Excellent corrosion resistance in a wide variety of corrosive environments including seawater and industrial acids
  • Readily formable and weldable
  • Excellent resistance to stress corrosion cracking


  • Chemical process equipment
  • Pollution control systems and wet scrubbers
  • Waste heat recovery exchangers
  • Tanks, vessels and agitators
  • Downhole equipment for corrosive/sour service
  • Nuclear reprocessing and handling

Chemical Composition:

Cr Ni Mo Co Nb (+Ta) Ti W Cu C Mn N Si P S Fe Al
Min 19.50 38.00 2.50 0.60 1.50 22.00
Max 23.50 46.00 3.50 1.20 3.00 0.05 1.00 0.50 0.03 0.20

Mechanical Properties:

0.2% Proof Stress 241 N/mm2 35 ksi
Tensile Strength 590 N/mm2 86 ksi
Elongation, 5.65√S0 and 4D 30%
Reduction of Area 40%
Hardness (Brinell) 327 max.


  1. Tensile testing shall be carried out in accordance with ASTM A370 or EN10002-1
  2. Minimum properties quoted (tested at room temperature in a longitudinal direction)
  3. Testing performed on each melt of material per heat treatment batch

Physical Properties:

Density (Kg.m-1) 81.4
Magnetic Permeability (20°C) 1.005
Curie Temperature (°C) -196
Young’s Modulus (N/mm2) 196
Specific Heat, 20°C (J/(g.K)) 440
Specific Electrical Resistance, 20°C (Ω-m) 0.00113
Thermal conductivity, 20°C (W/(m.K)) 10.8
Mean coefficient of thermal expansion, 20-100°C (/K) 14.1 x 10-6


Datasheet - NA-Alloy 825 (Bar)

Datasheet - NA-Alloy 825 (Bar)