ChemicalComposition:
General Introduction
Incoloy 825 (UNS N08825) is an austenitic nickel-iron-chromium alloy with additions of molybdenum, copper and titanium. It was developed to provide exceptional resistance to numerous corrosive environments, both oxidizing and reducing.
The nickel content of Incoloy 825 makes it resistant to chloride stresscorrosion cracking, and combined with molybdenum and copper, provides substantially improved corrosion resistance in reducing environments when compared to conventional austenitic stainless steels. The chromium and molybdenum content of Incoloy 825 provides resistance to chloride pitting, as well as resistance to a variety of oxidizing atmospheres. The addition of titanium stabilizes the alloy against sensitization in the as-welded condition. This stabilization makes Incoloy 825 resistant to intergranular attack after exposure in the temperature range which would typically sensitize un-stabilized stainless steels.
Incoloy 825 is resistant to corrosion in a wide variety of process environments including sulfuric, sulfurous, phosphoric, nitric, hydrofluoric and organic acids and alkalis such as sodium or potassium hydroxide, and acidic chloride solutions.
The fabrication of Incooy 825 is typical of nickel-base alloys, with material readily formable and weldable by a variety of techniques.
Characteristics of Incoloy 825
- Excellent resistance to reducing and oxidizing acids
- Good resistance to stress-corrosion cracking
- Satisfactory resistance to localized attack like pitting and crevice corrosion
- Very resistant to sulfuric and phosphoric acids
- Good mechanical properties at both room and elevated temperatures up to approximately 1020° F
- Permission for pressure-vessel use at wall temperatures up to 800°F
Chemical Composition
| Ni | Fe | Cr | Mb | Cu | Ti | C | Mn | S | Si | Al |
| 38.0-46.0 | 22.0 min | 19.5-23.5 | 2.5-3.5 | 1.5-3.0 | .6-1.2 | 0.05 max | 1.0 max | 0.03 max | 0.5 max | 0.2 max |
Density
8.14 g/cm3
Applications of Incoloy 825
- Chemical Processing
- Pollution-control
- Oil and gas well piping
- Nuclear fuel reprocessing
- Components in Pickling equipment like heating coils, tanks, baskets and chains
- Acid production
Corrosion Resistance
Incoloy 825 has a high level of corrosion resistance. It resists general corrosion, pitting, crevice corrosion, intergranular corrosion, and stress-corrosion cracking in both reducing and oxidizing environments.
Product Forms
- Sheet
- Plate
- Bar
- Pipe & Tube (welded & seamless)
- Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
- Wire
ceritificate
