825

Incoloy 825 is a nickel-base alloy generally similar to Alloy 20 in aqueous corrosion. It has useful resistance to boiling sulfuric acid up to 40% concentration, to 60% concentration at 176°F and in all concentrations to 150°F. Alloy 825 is stabilized annealed at the mill to resist intergranular corrosion as-welded. If exposed for long times to the sensitive temperature range 1200-1400°F the alloy may exhibit severe intergranular corrosion in certain very aggressive environments.

Chemistry

 NiCrMoMnCuSiCSTiAlFe
MIN 38.0 19.5 2.5 -- 1.5 -- -- -- 0.6 -- 22.0
MAX 46.0 23.5 3.5 1.0 3.0 0.05 0.05 0.03 1.2 0.2 --

Specifications

ASME SB 366ASME SB-163ASME SB-423
ASME SB-424ASME SB-425
ASME SB-705
ASTM B 163ASTM B 366
ASTM B 423
ASTM B 425
ASTM B 705Boiler & Pressure Vessel Code Section 1
ISO 15156-3
NACE MR0175
Nr./EN: 2.4858
Section III Class 3 Section VIII to 1000°F
UNS N08825UNS N08825 W.

Inventory

825 Pipe, 825 Plate, 825 Sheet, 825 Weld Wire

Common Trade Names

Alloy 825, Incoloy 825, Inconel 825

Features

  • Excellent resistance to sulfuric and phosphoric acids
  • Resists intergranular corrosion in the as-welded condition
  • Practical immunity to chloride stress corrosion cracking (SCC)
  • Resists polythionic acid SCC

Applications

  • Valves
  • Phosphoric acid production
  • Chemical process vessels
  • Catalytic cracking units

Physical Properties

Hustota: 0.294 lb/inch3 (1 lb/inch3 = 1/27,6 g/m3)
Bod tání: 1 371 - 1 399 °C
Magnetická permeabilita: 21 °C (H = Oersted) 1,005 

Temperature, °F 80 100 200 400 600 800 1000 1200 1400 1600 1800 2000
Coefficient* of Thermal Expansion, in/in°F x 10-6 -- -- 7.7 8.3 8.5 8.7 8.8 9.1 9.5 9.7 -- --
Thermal Conductivity
Btu • ft/ft2 • hr • °F
6.4 6.5 7.1 8.1 9.1 10.0 10.9 11.8 12.9 14.3 16.0 --
Electrical Resistivity,
ohm - circ mil/ft
678 680 687 710 728 751 761 762 765 775 782 793

* 70°F to indicated temperature.

Mechanical Properties

Minimum Specified Properties, ASME B 168

Ultimate tensile strength, ksi 85
0.2% yield strength, ksi 35
Elongation, % 30
Temperature, °F 80 500 1000 1200 1350 1500 1600 1700 1800
Ultimate Tensile Strength, ksi 100 -- 85.9 -- -- -- -- -- --
0.2% Yield Strength, ksi 43.5 -- 32.2 -- -- -- -- -- --
Modulus of Elasticity Dynamic,
psi x 106
28.3 36.4 23.8 22.7 21.7 20.3 19.4 18.3 17.3