Chemical Composition
| Grade | Ni | Fe | C | Mn | Si | Mo | Cu | Cr | Al | Ti | S |
| N08825 | 38.00 – 46.00 | ≥22.00 | ≤0.05 | ≤1.00 | ≤0.50 | 2.50 - 3.50 | 1.50- 3.00 | 19.50- 23.50 | ≤0.20 | 0.60 - 1.20 | ≤0.03 |
Overview
Nickel Alloy Incoloy N08825 Seamless Pipe is a high-performance piping material known for its exceptional corrosion resistance in a wide array of aggressive environments.
It is typically referenced by its trade name Incoloy 825 or its UNS designation N08825 (Werkstoff Nr. 2.4858).
Corrosion Resistance: The primary advantage is its excellent resistance to both reducing and oxidizing acids (like sulfuric and phosphoric acids), stress-corrosion cracking, and localized attacks such as pitting and crevice corrosion. The high nickel content helps resist chloride-ion stress-corrosion cracking, while molybdenum aids in resistance to pitting.
Mechanical Properties
Grade | Condition | Tensile Strength ksi(MPa) | Yield Strength ksi(MPa) | Elongation(%) |
N08825 | Annealed | ≥85(586) | ≥35(241) | ≥30 |
N08825 | Hot finished annealed | ≥75(517) | ≥25(172) | ≥30 |
N08825 | Cold-worked annealed | ≥85(586) | ≥35(241) | ≥30 |
N08825 | Hot-forming quality | - | - | - |
Features
Exceptional High-Temperature Oxidation Resistance: Withstands continuous service at 1150°C and intermittent use up to 1300°C, resisting scale formation in air, combustion gases, and carburizing atmospheres better than TP310H due to its higher silicon content.
Corrosion Resistance in Oxidizing Acids: Resistant to nitric acid, chromic acid, and hot alkaline solutions, though it is less effective in reducing environments (e.g., hydrochloric acid) compared to nickel-rich alloys.
Good Mechanical Properties at Elevated Temperatures: Maintains creep strength and ductility up to 1000°C, enabling use in stress-bearing components like furnace supports and retorts.
Moderate Fabricability: Can be welded using GTAW with 314L filler metal, though preheating (150-200°C) and slow cooling are recommended to prevent hot cracking. Cold forming requires higher forces due to its increased work-hardening rate.
Application
Industrial Furnaces: Used in radiant tubes, muffle furnaces, and heat treatment fixtures for carburizing, nitriding, and annealing processes, where exposure to 900-1200°C is common.
Cement & Glass Manufacturing: Employed in kiln liners, exhaust stacks, and glass melting furnaces, resisting alkali-induced corrosion and thermal shock.
Petrochemical Reforming: Suitable for steam reformer tubes and ethylene furnace coils operating at high temperatures with low sulfur content.
Aerospace Heat Exchangers: Used in auxiliary power units (APUs) and engine components requiring lightweight high-temperature resistance.
