Incoloy 825 (Alloy 825, UNS N08825) Pipe Description:
Incoloy alloys belong to a family of superalloys manufactured by Special Metals Corporation. They are nickel–iron–chromium alloys used in applications that require high corrosion resistance and high temperature strength. Their differing compositions dictate distinct application parameters.
The Alloy 825 is a nickel–iron–chromium alloy with additions of molybdenum, copper and titanium. Its chemical composition provides quantifiable resistance in corrosive environments. The nickel content is adequate to resist chloride ion stress corrosion cracking. Nickel combined with molybdenum and copper resists reducing environments containing sulphuric and phosphoric acids. Molybdenum reduces the likelihood of pitting and crevice corrosion. Chromium imparts resistance against oxidising agents such as nitric acid, nitrates and oxidising salts. Titanium stabilises the alloy during heat treatment. It prevents intergranular corrosion.
Other Trade Names: Alloy 825, Nickelvac 825, Nicrofer 4241

Incoloy 825 (Alloy 825, UNS N08825) Pipe Specifications:
Metal type: UNS N08825
Standards: ASTM B423, ASTM B829, ASTM B705, ASTM B775, ASTM B163, ASTM B704, ASTM B751, DIN 17751, ISO 6207, VdTÜV 432
Chemical Composition, %.
|
Ni |
Fe |
Cr |
Mo |
Cu |
Ti |
C |
Mn |
S |
Si |
Al |
Minimum |
38 |
22 |
19.5 |
2.5 |
1.5 |
0.6 |
|
|
|
|
|
Maximum |
46 |
|
23.5 |
3.5 |
3.0 |
1.2 |
0.05 |
1.0 |
0.03 |
0.5 |
0.2 |
Incoloy 825 (Alloy 825, UNS N08825) Pipe Applications:
- Equipment for sulphuric acid pickling plants, including heating coils, tanks, boxes, baskets and chains
- Dissolvers for fuel elements
- Components for offshore pipeline systems and pipes for acid gas service
- Sea water-cooled heat exchangers
- Paper industry – pipe heaters
- Pipelines for moist sulphur dioxide gas
- Plants for phosphoric acid production, including heat exchangers, evaporators and scrubbers
- LPG (liquefied petroleum gas) processing facilities, including air-cooled heat exchangers