Incoloy 825 is a titanium-stabilized fully austenitic nickel-iron-chromium alloy with additions of copper and molybdenum. It is approved for pressure vessels. Incoloy 825 (2.4858/N08825) is characterized by:High resistance to chloride-induced stress corrosion，Good resistance to chloride-induced pitting and crevice corrosion，Good resistance to oxidizing and non-oxidizing hot acids.
Quken offers Incoloy 825 in following forms:
| Product form | Standard | Size available mm |
|---|
| Strip | ASME SB409 | 0.05~2*2~540*C |
| Sheet/Plate | ASME SB409 | 2~25*1000~2000*2000~6000 |
| Flanges | ASME SB366 | Custom |
| Seamless pipe/tube | ASME SB407 | φ5~219*0.5~8.18*9000 Max |
| Welded pipe/tube | ASME SB154 | φ40~630*2~16*13000 Max |
| Bar | ASME SB408 | φ3.5~200*100~6000 |
| Wire | ASME SB408 | φ1~3*C |
| Pipe fittings | ASME SB366 | Custom |
| Forgings | ASME SB564 | Custom |
Designations and standards:
| Standard | Material designation |
|---|
| EN | 2.4858-NiCr21Mo |
| ISO | NiFe30Cr21Mo3 |
| UNS | NO8825 |
Chemical composition %:
| | Ni | Cr | Fe | C | Mn | Si | Co |
|---|
| MIN. | 38 | 19.5 | balance | | | | |
| MAX. | 46 | 23.5 | balance | 0.025 | 1 | 0.5 | 1 |
| | Cu | Mo | Al | Ti | P | S | |
|---|
| MIN. | 1.5 | 2.5 | | 0.6 | | | |
| MAX. | 3 | 3.5 | 0.2 | 1.2 | 0.02 | 0.015 | |
Corrosion Resistance Performance
Incoloy 825 is a versatile engineering alloy with resistance to corrosion in acids and alkalis under both oxidizing and reducing conditions. The high nickel content gives the alloy virtual immunity to stress corrosion cracking. The corrosion resistance in various media like sulfuric, phosphoric, nitric and organic acids is good, as well as the corrosion resistance in alkalis or ammoniac, sea water and caustic chloride. The versatility of Incoloy 825 is illustrated by its use in nuclear fuel element dissolvers where a variety of corrosive media, e. g. sulfuric and nitric acids and sodium hydroxide, are handled in the same equipment.
Physical Constants:
| Density | 8.14 g/cm3 (0.294 lb/in3) |
| Melting Range (Approx.) | 1,370-1,400 °C (2,500-2,550 °F) |
| Electrical Resistivity (20℃) | 112 Microhm· cm |
| Thermal Expansion Coefficient (20°C to 100°C) | 14.1 x 10-6/°C |
| Thermal Conductivity (100°C) | 12.4W/m·K |
Mechanical Properties:
| Yield Strength 0.2% Offset | Tensile Strength | Elongation In 2inches |
|---|
| KSI | MPa | KSI | MPa | % |
|---|
| 34.8 Min | 240 Min | 84.8 Min | 585 Min | 30 Min |
Applications
- Fuel element dissolvers
- Heat exchangers, evaporators, scrubbers, dip pipes etc. in phosphoric acid production
- Sea-water-cooled heat exchangers; offshore product piping systems; tubes and components in sour gas service
- Air-cooled heat exchangers in petroleum refineries
- Chemical and Food Processing
