Alloy 625 (UNS N06625 / 2.4856) is alloy with an addition of niobium that acts with the molybdenum to stiffen the alloy’s matrix and thereby provide high strength without strengthening heat treatment. The alloy resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion , it has good resistance to acids, such as nitric, phosphoric, sulfuric and hydrochloric, as well as to alkalis It has excellent mechanical properties at both extremely low and extremely high temperatures. Alloy 625 has high resistance to oxidation at elevated temperatures up to 1050°C .This nickel alloy has excellent weldability.
Chemical Composition
| Nickel Ni 58.0 | Chromium Cr 20.0-23.0% | Molybdenum Mo 8.0-10.0% | Manganese Mn 0.5% | Silicon Si 0.5% | Carbon C 0.10% |
Physical Properties
| Density at Room°C | Electrical Resistivity at 21°C | Termal Conductivity at 21°C | Modulus of Elasticity at Room °C | Mean Coefficient Thermal Expansion at 21-93°C |
| 8.44 g/cm3 | 1.29 Ω mm2/m | 9.8 W/m/°C | 200 GPa | 13.2μm/m°C |
Mechanical Properties
| Material | Yield Strength, 0.2 (MPa) |
Tensile Strength (MPa) |
Elongation, % |
| Alloy 625 | 275-415 | 690-830 | 30 |
Product Forms
| Product | Size (mm) | Condition of Supply |
| Wire | 0.2 – 12.0 | Soft Annealed Semi-Hard Hard |
| Bar | 5.0 – 60.0 | Hot Finished Cold Finished Peeled Bright Turned Bright Annealed |
Application:
Some typical applications of Alloy 625 are used in chemical processing, aerospace and marine engineering, pollution-control equipment, and nuclear reactors:
- Components where exposure to sea water and high mechanical stresses are required
- Oil and gas production where hydrogen sulfide and elementary sulfur exist at temperature in excess of 150°C
- Components exposed to flue gas or in flue gas desulfurization plants
- Flare stacks on offshore oil platforms
- Hydrocarbon processing from tar-sand and oil-shale recovery projects