Incoloy 825, also known as Alloy 825 (UNS N08825), is a high-performance nickel-iron-chromium alloy that is designed to withstand extreme industrial conditions. It has a wide range of uses in chemical processing, pollution control, and the oil and gas industries, and is well-known for its corrosion resistance, strength, and durability. Incoloy 825 is distinguished by the regulated addition of titanium to the material, which results in a solid metallurgical structure that retains performance stability even after welding and/or extended operation at high temperatures. This combination of qualities makes Incoloy 825 pipes, tubes, and fittings the material of choice for engineers and designers working on corrosion-critical applications.
In this blog, we will go over Incoloy 825 in great detail, including its chemical composition, key features, corrosion resistance, applications in many industries, and the benefits of the 825 material, which make it a must-have for design or performance critical applications.
What is Incoloy 825?
Incoloy 825 is a high-performance nickel-iron-chromium alloy with a high molybdenum, copper, and titanium content that makes it stronger and more resistant to oxidation. Because of the high levels of nickel, the chlorides make the alloy exceptionally resistant to stress corrosion cracking, ensuring that the austenitic structure remains consistent. Incoloy 825 is resistant to reducing agents and acids including molybdenum and copper, as well as oxidizing conditions involving chromium such as nitric acid, nitrates, and oxidizing salts. The titanium content ensures that pitting and intergranular corrosion of the alloy do not occur during fabrication and welding, even at high sensitization temperatures (650°C-760°C).
Alloy 825 is very efficient in the use of sulfuric and phosphoric acids, making it a very cost-effective and dependable alternative in chemical processing and other industries where corrosion resistance and lifespan are critical. To learn how Incoloy 825 compares to other superalloys, read our article to Inconel vs Incoloy.
Incoloy 825’s Chemical Composition and Key Elements
Incoloy 825 is a nickel-iron-chromium alloy designed to provide both excellent corrosion resistance and mechanical stability. Its balanced chemical structure makes it extremely efficient in highly industrialized settings such as chemical processing, oil and gas, and pollution management. It has a simple structure and is divided into components, as shown below:
Nickel (Ni) – 38.0-46.0%: The first is nickel, which increases the alloy’s resistance to stress corrosion cracking by chloride and improves its structural integrity under extreme conditions.
Iron (Fe) – 22.0% minimum: Iron forms the alloy’s backbone and offers structural integrity.
Chromium (Cr) – 19.5-23.5%: Chromium is utilized to protect the alloy surface from oxidation and corrosion, particularly in acidic environments, by generating a passive oxide layer.
Molybdenum (Mo) – 2.5-3.5%: Molybdenum improves pitting and crevice corrosion resistance, particularly in reducing environments like sulfuric and phosphoric acid solutions.
Copper (Cu) – 1.5-3.0%: Copper improves the resistance of reducing agents and makes the alloy more suitable for use in sulfuric acid applications.
Titanium (Ti) – 0.6–1.2%: Titanium stabilizes the alloy, preventing intergranular corrosion during welding or other high-temperature exposure.
Trace Elements (Mn, C, Si, S, Al): Manganese, carbon, silicon, sulfur, and aluminum are closely managed to provide manufacturing stability, mechanical strength, and corrosion resistance.
These factors, when combined, offer Incoloy 825 its synergistic chemical, mechanical, and thermal performance, making it a preferred alloy in key industrial processes that demand increased durability, dependable performance, and long-term corrosion protection.
Incoloy 825 Material Properties:
Incoloy 825 is used in a variety of industrial applications due to its outstanding mechanical, thermal, and corrosion resistance qualities. The material qualities that are important have been mentioned below.
The physical qualities of Incoloy 825 make it ideal for use in extreme environmental conditions in the industrial industry.
This material’s melting point ranges between 1350°C and 1400°C, making it acceptable for application at high temperatures.
Incoloy 825 has a density of 8.14 g/cm³, ensuring structural integrity and stability.
Thermal conductivity (12.5 W/m·K) is crucial for efficient heat transfer in industrial processes.
Its electrical resistivity of 0.75 µ ohm·m ensures its dependability in electrical use.
These characteristics make Incoloy 825 a viable alternative for heat transfer activities requiring great thermal stability. You can look through our selection of Incoloy 825 plates and sheets for applications that require flat-rolled product forms.
Incoloy 825 Mechanical Properties
Incoloy 825 (UNS N08825) has excellent tensile, yield, and elongation strengths, making it tough and dependable even under extreme working circumstances.
Tensile and Yield Strength
At room temperature, the tensile strength of Incoloy 825 varies from 80 to 120 ksi, whereas the yield strength is between 30 and 50 ksi. The values remain constant at high temperatures, demonstrating that the alloy is an extremely thermally stable material. Strongness and mild elongation are properties that ensure great performance during the forming and shaping procedures.
Typical Room Temperature Tensile Properties:
| Form | Condition | 0.2% Proof Stress (MPa) | Tensile Strength (MPa) | Elongation (%) |
| Tube | Annealed | 440 | 770 | 35 |
| Tube | Cold Drawn | 880 | 1000 | 15 |
| Bar | Annealed | 325 | 690 | 45 |
| Plate | Annealed | 340 | 660 | 45 |
| Sheet | Annealed | 420 | 760 | 39 |
Corrosion Resistance of Incoloy 825
Because of its high level of corrosion resistance, Incoloy 825 is ideal for use in harsh industrial environments. It is a high-performance alloy that is extremely resistant to general corrosion, pitting, crevice, and intergranular stress-corrosion cracking. Incoloy 825 is another material that is excellent for use in industries dealing with hard chemicals, oil and gas, and even marine since it can endure the harsh conditions of chemicals. For a full comparison of Incoloy 825 to other high-performance alloys, see our blog post Incoloy 825 vs Inconel 625.
Fabrication and welding of Incoloy 825 alloy.
Incoloy 825 (Alloy 825, UNS N08825) is a particularly adaptable alloy in terms of manufacturing and welding, making it ideal for a wide range of industrial production processes requiring corrosion resistance and good mechanical capabilities.
Production of Alloy 825
The alloy is readily hot or cold worked, allowing great flexibility in shaping.
Hot Working: The recommended range is 870-1180°C, with a finishing temperature of 870-980°C. To guarantee optimal corrosion resistance, hot work components should undergo stabilizing annealing.
Cold Working: Incoloy 825 is easier to cold form than other stainless steels, and components can be formed precisely.
welding of Incoloy 825
Incoloy 825 is easily weldable using common techniques, including:
GTAW (TIG): Gas Tungsten Arc Welding.
GMAW (MIG): Gas Metal Arc Welding.
SMAW: Shielded Metal Arc Welding.
SAW: Submerged Arc Welding.
To accomplish high-quality welding of Incoloy 825, clean joints are essential to keep the weld pool contaminant-free. They can preheat and apply post-weld heat treatment to lessen the possibility of cracking, particularly in high-temperature locations. Welding devices, especially MIG liners, should be adequately maintained to avoid some of the most evident issues, including as burnbacks, unstable arcs, and wire feeding irregularities. Furthermore, the duty-cycle rating of monitoring equipment regulates heat and prevents overheating, ensuring a smooth and dependable welding operation. Our Incoloy 825 filler wire page contains detailed specifications for welding consumables.
Recommended Welding Consumables
| Service Condition | Welding Electrode | Filler Metal | Flux-Cored Wire |
| Normal Service | Inconel WE 112 | Inconel FM 625 | Inco Cored 625DH |
| Higher Strength | Inconel WE 112 | Inconel FM 625 | Inco Cored 625DH |
| Best Corrosion Resistance | Inconel WE 112 | Inconel FM 625 | Inco Cored 625DH |
Using the proper welding consumables and fabrication techniques guarantees that Incoloy 825 retains its corrosion resistance, mechanical integrity, and durability in demanding industrial applications.
Industrial Applications for Incoloy 825
Incoloy 825 is a high-performance nickel-iron-chromium alloy that excels in demanding industrial environments. Its remarkable properties make its application ideal in:
Chemical processing plants include heat exchangers, pipeline systems, and reactors.
Oil and gas are components of the extraction, refining, and transportation systems. Our Incoloy 825 pipe spools are commonly used throughout these installations.
Marine Applications: Marine equipment is exposed to salt water and corrosive marine air. Incoloy 825 instrumentation valves are the best choice in this situation.
Turbines, high-temperature pressure vessels, and other power generation equipment.
Its adaptability and durability make it suitable for use in a variety of industries, including automotive, aerospace, and building.
Why is Incoloy 825 the material of choice?
Incoloy 825 is a lightweight polymer that can survive harsh environments. Because it offers excellent corrosion resistance, strength, and stability at high temperatures. One of the reasons it has proven so effective as a shield against oxidation and acidic environments is its chemical composition, which includes nickel, chromium, molybdenum, and copper. The alloy’s physical and mechanical qualities also aid in effective heat conduction and durability in high-temperature activities, but its construction allows for a wide range of applications that can readily be integrated into industrial systems. Incoloy 825 is a low-cost, high-performance alloy used in the chemical process, maritime, oil and gas, and high-temperature industries. It is also highly durable and reliable.
Enhance the whole line of high-performance metals by incorporating all Incoloy 825 round bars, pipelines, flanges, and fasteners into your industrial projects to make them better and finer. Request a quote and identify the best product to use.
