What is an Incoloy Alloy？

Incoloy alloy is a family of nickel-chromium-based alloys that are known for their excellent corrosion resistance, high-temperature strength, and good mechanical properties. These alloys are primarily composed of nickel, chromium, and iron, and they may contain other elements such as molybdenum, copper, and titanium. Incoloy alloys are designed for use in harsh environments, particularly those involving high temperatures and corrosive conditions. This makes Incoloy steel ideal for applications such as furnaces, boilers, heat exchangers and thermowells.

Incoloy Material Composition:

• Nickel (Ni): Provides corrosion resistance and enhances high-temperature strength.
• Chromium (Cr): Contributes to corrosion resistance, especially in oxidizing environments.
• Iron (Fe): Mainly present for structural stability and balance.

Incoloy Grades

Incoloy alloys are available in different grades, each with unique properties. Some of the commonly used grades Incoloy 800, Incoloy 800H, Incoloy 800HT, Incoloy 825.

1. Incoloy 800 (UNS N08800):

Composition:

• Nickel (Ni): 30-35%
• Chromium (Cr): 19-23%
• Iron (Fe): 39.5% min
• Other elements: Small amounts of aluminum, titanium, and copper.

Incoloy Alloy 800 Mechanical Behavior:

• Tensile Strength: Approximately 75,000 psi (515 MPa) 100,000 psi (690 MPa)
• Yield Strength (0.2% Offset): Approximately 30,000 psi (205 MPa)
• Elongation at break: about 30%-40%
• Hardness: 75-90 Rockwell B
• Density: Approximately 0.287 lb/in³ (7.94 g/cm³)

High-Temperature Characteristics:

• Operating Temperature: Up to approximately 1100°C (2010°F).
• Good resistance to oxidation, carburization, and sulfidation.

1.4876 alloy 800 Applications:
Heat exchangers, furnace components, petrochemical processing equipment.

2. Incoloy 800H (UNS N08810):

Composition:

• Nickel (Ni): 30-35%
• Chromium (Cr): 19-23%
• Iron (Fe): 39.5% min
• Carbon (C): 0.05-0.10%
• Other elements: Small amounts of aluminum, titanium, and copper.

Nickel Incoloy 800H Mechanical Behavior:

• Tensile Strength: Approximately 75,000 psi (515 MPa) 100,000 psi (690 MPa)
• Yield Strength (0.2% Offset): Approximately 30,000 psi (205 MPa)
• Elongation at break: about 30%-40%
• Hardness: 75-90 Rockwell B
• Density: Approximately 0.287 lb/in³ (7.94 g/cm³)

High-Temperature Characteristics:

• Operating Temperature: Up to approximately 1100°C (2010°F).
• Higher carbon content provides enhanced high-temperature strength.

EN 1.4858 alloy 800H Applications:
Chemical and petrochemical processing, heat-treating equipment.

3. Incoloy 800HT (UNS N08811):

Composition:

• Nickel (Ni): 30-35%
• Chromium (Cr): 19-23%
• Iron (Fe): 39.5% min
• Aluminum (Al): 0.85-1.20%
• Titanium (Ti): 0.30-0.60%
• Other elements: Small amounts of copper and molybdenum.

Incoloy alloy 800HT Mechanical behavior:

• Tensile Strength: Approximately 75,000 psi (515 MPa) 100,000 psi (690 MPa)
• Yield Strength (0.2% Offset): Approximately 30,000 psi (205 MPa)
• Elongation at break: about 30%-40%
• Hardness: 75-90 Rockwell B
• Density: Approximately 0.287 lb/in³ (7.94 g/cm³)

High-Temperature Characteristics:

• Operating Temperature: Up to approximately 1200°C (2190°F).
• Additional heat treatment for improved high-temperature strength.

1.4959 Incoloy 800HT Applications:
Nitric acid catalyst supports, ethylene dichloride crackers, furnace components.

4. Incoloy 825 (UNS N08825):

Incoloy 825 Composition:

• Nickel (Ni): 38-46%
• Chromium (Cr): 19.5-23.5%
• Iron (Fe): 22% min
• Molybdenum (Mo): 2.5-3.5%
• Copper (Cu): 1.5-3%
• Titanium (Ti): 0.6-1.2%

Incoloy 825 Mechanical Behavior:

• Tensile Strength: Approximately 80,000 psi (550 MPa)
• Yield Strength (0.2% Offset): Approximately 32,000 psi (220 MPa)
• Elongation at break: about 30%
• Hardness: 85 Rockwell B
• Density: Approximately 0.294 lb/in³ (8.14 g/cm³)

High-Temperature Characteristics:

• Operating Temperature: Up to approximately 870°C (1600°F).
• Excellent corrosion resistance, particularly in acidic environments.

2.4858 alloy 825 Applications:
Chemical processing, pollution control, oil and gas, marine engineering.

High-Temperature Comparison:
Incoloy 800, 800H, and 800HT all have excellent high-temperature resistance, with 800HT providing the highest strength at elevated temperatures. Incoloy 825, while not reaching the same temperatures as the 800 series, is preferred for its exceptional corrosion resistance in various harsh environments.

The Following Are Common Incoloy Alloy Product Forms:

1. ASTM B407 Tubes and Pipes :
Supply of seamless and welded pipes in various diameters and wall thicknesses for industries such as chemical, oil and gas.

2. ASTM B409 Sheets and plates:
Available in sheets of different thicknesses and widths for manufacturing pressure vessels, petrochemical equipment, heat exchangers, etc.

3. Bars and Wires ASTM B408:
Rods of round, square and hexagonal cross-sections are available in different diameters, as well as wire rods of various diameters, suitable for the manufacture of valves, pumps and other mechanical parts.

4. Welding Materials:
Includes welding wire and rods used to join or repair Incoloy alloy components during manufacturing and repair processes.

5. ASTM B564 Flanges:
Available in various sizes and types of flanges for connecting pipes and equipment.

6. Fittings:
Provide pipe fittings of various shapes and specifications, including elbows, tees, flange blind plates, etc., for connecting and changing the direction of pipes.

8. Forgings:
Forged products, such as forging blanks, forging rings and forgings, are used to manufacture high-strength structural components.

9. Components for Devices:
Includes various pre-fabricated components such as valves, pumps and sensors, suitable for direct installation and use.