Overview
Both Inconel 625 and Hastelloy C-276 are nickel-chromium-molybdenum based alloys. They all have excellent corrosion resistance and good strength.
Comparing the two alloys, Inconel 625 has a higher chromium content, while Hastelloy C-276 has a higher molybdenum content. This makes them different in corrosion resistance in different environments.
This article will compare these two alloys in detail from various aspects.
Basic Information
Name
Inconel 625
UNS N06625
W.Nr. 2.4856
Brand
INCONEL®
Matrix
Type
Solid Solution
Strengthened Alloy
Density
8.44 g/cm³
Use Temperature
High Temperature
Name
Hastelloy C-276
UNS N10276
W.Nr. 2.4819
Brand
HASTELLOY®
Matrix
Type
Solid Solution
Strengthened Alloy
Density
8.89 g/cm³
Use Temperature
High Temperature
Introduction
Inconel 625
INCONEL® nickel-chromium alloy 625 (UNS N06625 / W.Nr. 2.4856) is used for its high strength, excellent fabricability (including joining), and outstanding corrosion resistance. Service temperatures range from cryogenic to 1800°F (982°C).
Hastelloy C-276
HASTELLOY® C-276 alloy (UNS N10276) was the first wrought, nickel-chromium-molybdenum material to alleviate concerns over welding (by virtue of extremely low carbon and silicon contents). As such, it was widely accepted in the chemical process and associated industries, and now has a 50-year-old track record of proven performance in a vast number of corrosive chemicals.
Chemical Composition
Corrosion Resistance
Inconel 625
Oxidation Resistance
Hastelloy C-276
Reduction Resistance
The nickel and iron content of Inconel 625 and Hastelloy C-276 are very close. The main difference between them is chromium and molybdenum.
Chromium
Alloy 625 has more chromium content than alloy C-276, and chromium is shown as oxidation resistance in terms of corrosion resistance. This makes Inconel 625 has better corrosion resistance in oxidizing environments (such as concentrated sulfuric acid, nitric acid, etc.).
Molybdenum
In contrast, alloy C-276 has more molybdenum content than alloy 625. The molybdenum element can play a very good anti-reduction effect. In some reducing environments (such as: hydrochloric acid, hydrogen sulfuric acid), alloy C-276 has better performance.
Mechanical Behavior
Inconel 625
Tie
Hastelloy C-276
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Inconel 625 and Hastelloy C-276 are both solid solution strengthened alloys, with little difference in mechanical properties. It's just that they mainly use different solid solution strengthening elements.
Niobium and Tantalum
There is a certain amount of niobium and tantalum in alloy 625, and the solid solution strengthening effect of niobium and tantalum is very good. This brings very good strength to alloy 625.
At the same time, in alloy 625, niobium and tantalum have a small amount of precipitation strengthening effect (generally alloy 625 does not do aging treatment), which further ensures the strength of the alloy.
Tungsten and Molybdenum
Unlike alloy 625, alloy C-276 mainly relies on solid solution strengthening of tungsten and molybdenum. The atomic radii of tungsten and molybdenum are also very large, so their strengthening effect on alloy C-276 is also very obvious.
Physical Properties
| Inconel 625 | Inconel 718 | |
|---|---|---|
| Density, g/cm³ | 8.44 | 8.89 |
| Density, lb/in.³ | 0.305 | 0.321 |
| Melting Range, °F | 2350-2460 | 2415-2500 |
| Melting Range, °C | 1290-1350 | 1323-1371 |
Application
It can be seen that both alloys have very wide applications. And their application range is very close to a large extent. But this does not mean that the two alloys can be substituted for each other. In the same application, we should also choose different alloys according to the application environment.
For example, in oil & gas applications, the underground environment of different oil fields is very different. Some oil fields are in an oxidizing environment, in this case Inconel 625 is more suitable. For oil fields in reducing environments, Hastelloy C-276 should be used.
Supported Products
Inconel 625
Main Standards
Inconel 625
Seamless Pipe and Tube: ASTM B444, ASTM B829
Welded Pipe: ASTM B705, ASTM B775
Welded Tube: ASTM B704, ASTM B751
Welded Fittings: ASTM B366
Rod and Bar: ASTM B446
Forgings: ASTM B564
Plate, Sheet, and Strip: ASTM B443
Hastelloy C-276
Seamless Pipe and Tube: ASTM B622, ASTM B983
Welded Pipe: ASTM B619
Welded Tube: ASTM B626
Fittings: ASTM B366, ASTM B462
Billet, Rod and Bar: ASTM B574
Forgings: ASTM B564, ASTM B462
Plate, Sheet, and Strip: ASTM B575
Price
Monel 400
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Monel K-500
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Generally speaking, the price of molybdenum will be a little higher than that of chromium, so the price of Hastelloy C-276 will be slightly higher. But overall, their prices are not much different.
Conclusion
Both Inconel 625 and Hastelloy C-276 have good corrosion resistance. Inconel 625 is more suitable for oxidizing environments. Hastelloy C-276 is more suitable for reducing environments.
Both alloys are solid solution strengthened alloys. Although the elements that play a solid solution strengthening effect are different, overall the mechanical properties of the two are not much different.
The application ranges of the two alloys are similar, but they play different roles in the same application.
AEETHER can produce Inconel 625 and Hastelloy C-276 alloy products according to your requirements. If you have purchase needs, please do not hesitate to contact us:
