Whether you are a supplier or a end user of Inconel alloys, you may face challenges when deciding between Incoloy 800 and Incoloy 825 alloy or advising customers on material selection.
Incoloy 825 is an enhanced version of Incoloy 800, with added molybdenum and copper.
These additions give alloy 825 superior corrosion resistance compared to alloy 800.
In this article, we will provide a detailed comparison of the performance characteristics between Incoloy 800 and Incoloy 825.
INCOLOY alloy 800 (UNS N08800 / W.Nr. 1.4876) is a widely used material for construction of equipment requiring corrosion resistance, heat resistance, strength, and stability for service up to 1500°F (816°C). Alloy 800 offers general corrosion resistance to many aqueous media and, by virtue of its content of nickel, resists stress corrosion cracking. At elevated temperatures it offers resistance to oxidation, carburization, and sulfidation along with rupture and creep strength.
What is Incoloy Alloy 825?
INCOLOY® alloy 825 (UNS N08825 / W.Nr. 2.4858) is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. The alloy’s chemical composition is designed to provide exceptional resistance to many corrosive environments. The resistance of INCOLOY alloy 825 to general and localized corrosion under diverse conditions gives the alloy broad usefulness.
Incoloy Alloy 800 vs Incoloy Alloy 825 Chemical Composition
Here’s a comparison table for the chemical composition of Incoloy 800 and Incoloy 825:
Incoloy Alloy 800 vs Incoloy Alloy 825 Corrosion Resistance
Alloy 825 contains less iron and more nickel, enhancing its fundamental corrosion resistance.
Both alloys possess significant chromium content, ensuring excellent oxidation resistance.
The addition of molybdenum in alloy 825 provides superior resistance to reducing environments such as sulfuric and phosphoric acids, as well as enhancing resistance to pitting and crevice corrosion.
Furthermore, the higher copper content in Incoloy 825 contributes to its exceptional corrosion resistance, particularly at room temperature.
Overall, alloy 825 exhibits superior corrosion resistance across all aspects compared to alloy 800.
Incoloy Alloy 800 vs Incoloy Alloy 825 Mechanical Behavior
Both Incoloy 800 and Incoloy 825 are solid solution strengthened alloys. Because some molybdenum is added to 825 to make the solid solution strengthening effect better, its overall strength will be higher. But there is no obvious difference in strength between the two alloys. They mainly differ in corrosion resistance.
Incoloy Alloy 800 vs Incoloy Alloy 825 Physical Properties
| Incoloy 800 | Incoloy 825 | |
|---|---|---|
| Density, g/cm³ | 7.94 | 8.14 |
| Density, lb/in.³ | 0.287 | 0.294 |
| Melting Range, °F | 2475-2525 | 2500-2550 |
| Melting Range, °C | 1357-1385 | 1370-1400 |
| Permeability at 200 oersted (15.9 kA/m) | 1.009-1.014 | 1.005 |
| Curie Temperature, °F | -175 | <-320 |
| Curie Temperature, °C | -115 | <-196 |
Incoloy Alloy 800 vs Incoloy Alloy 825 Application
INCOLOY alloy 800 is used in a variety of applications involving exposure to corrosive environments and high temperatures. It is used for heat-treating equipment such as baskets, trays, and fixtures. In chemical and petrochemical processing, the alloy is used for heat exchangers and other piping systems in nitric acid media especially where resistance to chloride stress-corrosion cracking is required. In nuclear power plants, it is used for steam-generator tubing. The alloy is often used in domestic appliances for sheathing of electric heating elements. In the production of paper pulp, digester-liquor heaters are often made of alloy 800. In petroleum processing, the alloy is used for heat exchangers that air cool the process stream.
The resistance of INCOLOY alloy 825 to general and localized corrosion under diverse conditions gives the alloy broad usefulness. Applications include chemical processing, pollution control, oil and gas recovery, acid production, pickling operations, nuclear fuel reprocessing, and handling of radioactive wastes.
Incoloy Alloy 800 vs Incoloy Alloy 825 Main Standards
Here’s a comparison table for the standards of Incoloy 800 and Incoloy 825:
Incoloy Alloy 800 vs Incoloy Alloy 825 Cost
Due to its enhanced corrosion resistance and more intricate composition compared to Incoloy 800, Incoloy 825 commands a slightly higher price.
For applications where the operating environment is not excessively harsh, alloy 800 is often recommended to minimize costs.
Conclusion
Incoloy 825 enhances its corrosion resistance by incorporating molybdenum and copper compared to Incoloy 800, making it widely suitable for complex environments.
Both alloys benefit from solid solution strengthening, with comparable mechanical properties.
Given its lower cost, Incoloy 800 is often preferred when both alloys are viable options.
HZW manufactures cost-effective Incoloy 800 and Incoloy 825 products. For specific requirements, please feel free to reach out to our team.
