Incoloy 800 at a Glance
Incoloy 800 is a nickel-iron-chromium-based corrosion-resistant alloy containing 30%–35% nickel and 19%–23% chromium, specifically designed for high-temperature oxidation and carburization resistance. It has a density of 8.0 g/cm³, a melting range of 1350–1400°C, and maintains a tensile strength above 400 MPa at 650°C. It is suitable for demanding environments such as chemical reactors and aircraft engine blades.
Note: Inconel 800 and Incoloy 800 are different designations for the same alloy series and refer to the identical material.
I. Incoloy 800 Chemical Composition (wt%)
| Element | Range | Function |
|---|---|---|
| Nickel (Ni) | 30.0–35.0 | Provides corrosion resistance and high-temperature strength; stabilises austenitic structure |
| Iron (Fe) | 39.5–46.0 | Forms the matrix; enhances machinability |
| Chromium (Cr) | 19.0–23.0 | Improves oxidation resistance; forms a dense protective oxide layer |
| Aluminum (Al) | 0.15–0.60 | Enhances creep resistance and high-temperature stability |
| Titanium (Ti) | 0.15–0.60 | Stabilises carbides; improves resistance to intergranular corrosion |
| Copper (Cu) | ≤0.75 | Optimises adaptability in specific corrosive environments |
| Carbon (C) | ≤0.10 | Controls impurities; affects workability |
| Manganese (Mn) | ≤1.50 | Aids deoxidation; improves hot workability |
| Silicon (Si) | ≤1.00 | Enhances oxidation resistance |
| Sulfur (S) | ≤0.015 | Tightly controlled to prevent hot shortness |
| Phosphorus (P) | ≤0.030 | Controls impurities; maintains toughness |
II. Incoloy 800 Physical Properties
| Parameter | Value |
|---|---|
| Density | 8.0 g/cm³ |
| Melting Range | 1350–1400°C |
| Specific Heat Capacity | 455 J/(kg·℃) |
| Magnetic Attraction | Non-magnetic |
| Coefficient of Thermal Expansion (20–100°C) | Approx. 12×10⁻⁶/℃ |
| Thermal Conductivity (20°C) | Approx. 17 W/(m·K) |
The low coefficient of thermal expansion allows the alloy to maintain good dimensional stability at high temperatures. The moderate thermal conductivity helps conduct heat effectively and avoid localised overheating.
III. Incoloy 800 Mechanical Properties
Room Temperature Properties
Tensile Strength: ≥ 650 MPa
Yield Strength: ≥ 275 MPa
Elongation: 30%–40%
High-Temperature Properties (650°C)
Tensile Strength: ≥ 400 MPa
Yield Strength: Approx. 150 MPa
The alloy exhibits good creep resistance at elevated temperatures, allowing it to maintain shape and strength under prolonged high-temperature stress.
IV. Corrosion Resistance
Oxidation Resistance: Excellent. Forms a dense chromium oxide layer at high temperatures, effectively preventing further oxygen diffusion and protecting the base material.
Media Corrosion Resistance: Resists attack from various chemical media, including oxidising acids (e.g., nitric acid), medium-concentration sulfuric acid, and sodium hydroxide.
Chloride Corrosion Resistance: Demonstrates good resistance to pitting and crevice corrosion in chloride-containing environments.
V. Fabrication and Weldability
| Process | Description |
|---|---|
| Hot Forming | Forging, rolling, and extrusion are applicable. Temperature range: 1100–1200°C |
| Cold Forming | Due to high strength and work hardening characteristics, cold forming is more difficult and requires precision equipment and appropriate process parameters |
| Welding | Good weldability. Various methods are applicable, including SMAW, GTAW/GMAW, and electron beam welding. Proper filler metal and process parameters must be selected |
VI. Major Applications
| Industry | Typical Components |
|---|---|
| Chemical | Reactors, heat exchangers, piping, valves (high temperature, high pressure, strongly corrosive media) |
| Energy | High-temperature power plant piping, boiler components, nuclear reactor fuel element cladding |
| Aerospace | Aircraft engine combustion chambers, turbine blades, turbine disks (high temperature, high pressure, high-speed rotation) |
| Marine Engineering | Seawater piping, offshore platform structural components, and marine chemical equipment |
Summary: Why Choose Incoloy 800?
Excellent high-temperature strength, maintaining good mechanical properties at 650°C
Strong oxidation and carburization resistance, suitable for prolonged high-temperature service
Resists various corrosive media, including oxidising acids and chloride-containing environments
Good hot formability and weldability, allowing fabrication of complex components
Well-established industrial track record with clear material standards (e.g., ASTM B407, B408)
For material test certificates, technical data sheets, or custom sizes and quotes, please contact us. Email:baohui@bhsteelpipe.com
