Incoloy 800 vs. Incoloy 840 – Which alloy is better?
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Incoloy 800 vs. Incoloy 840 – Which alloy is better?
Incoloy 800 is generally better suited for high-temperature applications and environments requiring excellent oxidation and carburization resistance, while Incoloy 840 is better suited for general heating elements and applications requiring better corrosion resistance and excellent formability in acidic environments. Specific grades of Incoloy 800, such as 800H and 800HT, have higher creep strength and tensile strength to meet the more demanding requirements of high-temperature applications.
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What are the applications of Incoloy 800 alloy?
It is used in the manufacture of heat treatment equipment, such as baskets, pallets, and clamps. In chemical and petrochemical processing, this alloy is used in heat exchangers and other piping systems for nitric acid media, particularly suitable for applications requiring resistance to chloride stress corrosion cracking.
Properties of Incoloy 800
Incoloy 800 is a nickel-chromium alloy with good strength and excellent resistance to oxidation and carburization at high temperatures. It also exhibits excellent resistance to stress corrosion cracking and is relatively easy to weld. Incoloy 800 can be used at temperatures up to 1100°F (593°C). It is considered an age-hardening alloy because its strength increases over time. Due to its excellent corrosion resistance, Incoloy 800 is commonly used in heat exchangers, pressure vessels, and other components exposed to corrosive environments.
Properties of Incoloy 840
Unlike Incoloy 800, Incoloy 840 is an austenitic alloy containing chromium, nickel, and molybdenum. This alloy exhibits good resistance to reducing and oxidizing acid corrosion, as well as resistance to stress corrosion, cracking, and pitting corrosion. This makes it ideal for petrochemical applications, such as pump shafts or turbine blades, which must withstand long-term exposure to highly corrosive chemicals without corrosion or performance degradation. However, unlike Incoloy 800, its strength cannot be increased through age hardening. Furthermore, its maximum service temperature is limited to 1000°F (538°C).
The difference between Incoloy 800 and Incoloy 840
Chemical component (%):
|
Grade |
Chemical Composition % |
|||||||||||
|
C |
Mn |
P |
S |
Si |
Cr |
Ni |
Mo |
Ti |
Cu |
Al |
N |
|
|
Incoloy 800 |
0.10 |
1.50 |
0.045 |
0.015 |
1.00 |
19.0-23.0 |
30.0-35.0 |
_ |
_ |
0.75 |
0.15-0.60 |
_ |
|
Incoloy 840 |
0.08 |
1.00 |
0.03 |
0.015 |
1.00 |
18.0-22.0 |
18.0-22.0 |
_ |
0.60 |
0.75 |
0.60 |
_ |
Mechanical requirements:
|
Grade |
Tensile Strength MPa |
Yield Strength MPa |
Elongation % |
|
Incoloy 800 |
87(600) |
39.9(275) |
45 |
|
Alloy 840 |
83(572) |
35(241) |
40 |
Comparison: Incoloy 800 vs. Incoloy 825
| Feature | Incoloy 800 | Incoloy 825 |
|---|---|---|
| Primary Advantage | Higher mechanical strength at room temperature | Better corrosion resistance at high temperatures |
| Key Alloying Elements | Nickel, Chromium, Iron | Nickel, Chromium, Iron, Molybdenum |
| Corrosion Resistance | Good resistance to oxidation and carburization | Superior resistance to oxidation, pitting, and chloride-containing media like seawater |
| High-Temperature Strength | Good strength at elevated temperatures | Excellent creep and rupture strength, with a maximum operating temperature around 1000°C |
| Applications | Furnace components, heat exchangers, and carburizing fixtures | Immersion heaters, industrial heating elements, and applications involving salt-containing environments |
Why Choose Gnee Nickel Alloy (Supplier Example)?
✅ Large stock of Incoloy alloy tubes/bars/plates/fittings/coils, fast shipping.
✅ Factory direct sales, highly competitive prices, excellent value for money.
✅ Comprehensive quality assurance: Material Testing Certificate (MTC), chemical composition certificate, and mechanical property certificate.
✅ Value-added services: slitting, cutting, polishing, surface treatment.
✅ Worldwide shipping, secure and reliable packaging, and provision of export-required documents.
Email: ss@gneemetal.com
Gnee Steel is a supplier of incoloy 800 alloy, offering a wide range of products including: seamless pipe (sizes: 4-219 mm; thickness: 0.5-20 mm); welded pipe (sizes: 5.0-1219.2 mm; thickness: 0.5-20 mm); plates (thickness: 0.1 to 100 mm; width: 10-2500 mm); strips; alloy round bars (diameter: 3-800 mm); flat bars (thickness: 2-100 mm; width: 10-500 mm); hexagonal bars (size: 2-100 mm); wire rods; and extruded profiles. We collaborate with steel mills to provide our customers with incoloy 800 alloy products that meet or exceed numerous leading industry standards, including ASTM, ASME, SAE, AMS, ISO, DIN, EN, and BS standards.
Gnee Steel stocks and sells incoloy 800, pipes, plates, strips, round bars, flat bars, forged billets, hexagonal steel, wire rods, and extruded profiles. Please feel free to contact us at ss@gneesteel.com for a quote.
