The differences between Hastelloy C22 and C276 Alloy
The differences between Hastelloy C22 and C276 Alloy
Due to its higher chromium content, Hastelloy C22 offers broader and superior corrosion resistance in oxidizing environments (such as wet chlorine), making it more suitable for general corrosive environments. C276, on the other hand, contains more molybdenum and tungsten, performing exceptionally well under reducing conditions and in chloride environments, exhibiting better resistance to stress corrosion cracking and reducing environments (such as wet chlorine vapor). Nevertheless, C22 has better weldability and resistance to intergranular corrosion after welding, while C276 is often more cost-effective in specific, harsh chloride/reducing environments.
What are the characteristics of C22 alloy?
C22 alloy possesses excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking. It exhibits superior corrosion resistance in oxidizing aqueous media, including acids containing oxidizing agents, wet chlorine, and mixtures containing nitric acid or other oxidizing acids and chloride ions.
Overview and Differences Between Hastelloy C22 and C276
Hastelloy C276 is a high-performance nickel-chromium-molybdenum alloy. It contains approximately 57% nickel, 16% chromium, and 16% molybdenum, as well as elements such as iron, tungsten, and cobalt. Its standard designation is UNS N10276. C276 is commonly used in strong acid environments, such as sulfuric acid, hydrochloric acid, and chloride solutions.
Hastelloy C22 was developed to improve the corrosion resistance of C276 in welded areas. It is also a nickel-chromium-molybdenum alloy, containing approximately 56% nickel, 22% chromium, 13% molybdenum, and small amounts of iron, tungsten, and cobalt. Its standard designation is UNS N06022. Compared to C276, C22 offers better and more comprehensive corrosion resistance. It also performs better in terms of resistance to pitting corrosion, crevice corrosion, intergranular corrosion, and stress corrosion cracking.
Hastelloy C22 and C276 Chemical Composition Difference
| Element | Composition of Hastelloy C22 (UNS N06022/W N 2.4602) (%) | Composition of Hastelloy C276 (UNS N10276/W N 2.4819) (%) |
| Carbon (C) | ≤0.015 | ≤0.01 |
| Manganese (Mn) | ≤0.50 | ≤1.00 |
| Phosphorus (P) | ≤0.02 | ≤0.04 |
| Sulfur (S) | ≤0.02 | ≤0.03 |
| Silicon (Si) | ≤0.08 | – |
| Chromium (Cr) | 20.0 – 22.5 | 14.5 – 16.5 |
| Nickel (Ni) | Remainder (rem) | Remainder (rem) |
| Molybdenum (Mo) | 12.5 – 14.5 | 15.0 – 17.0 |
| Cobalt (Co) | ≤2.5 | ≤2.5 |
| Iron (Fe) | 2.0 – 6.0 | 4.0 – 7.0 |
| Tungsten (W) | 2.5 – 3.5 | 3.0 – 4.5 |
| Vanadium (V) | ≤0.35 | ≤0.35 |
Hastelloy C276 and C22 Physical Properties Difference
| Property | Hastelloy C22 (UNS N06022/W N 2.4602) | Hastelloy C276 (UNS N10276/W N 2.4819) |
| Density (g/cm³) | 8.9 | 8.89 |
| Melting Point (°C) | 1325 – 1370 | 1350 – 1390 |
Corrosion Resistance
Hastelloy C22 and C276 are renowned for their excellent corrosion resistance in a wide range of environments:
| Corrosion Type | Hastelloy C22 | Hastelloy C276 |
|---|---|---|
| Oxidizing Environments | Excellent resistance to oxidizing acids like nitric acid | Excellent resistance to oxidizing acids such as ferric and cupric chlorides |
| and mixed acids containing nitric acid and chlorides. | ||
| Reducing Environments | Highly resistant to reducing media, offering superior | Strong resistance to reducing acids like sulfuric acid and |
| performance against sulfuric acid, hydrochloric acid, | hydrochloric acid | |
| phosphoric acid, and organic acids. | ||
| Chloride Environments | Exceptional resistance to chloride-induced pitting and | Superior resistance to chloride-induced stress corrosion |
| crevice corrosion. | cracking (SCC) and pitting |
Temperature Capability
Both alloys exhibit robust performance at high temperatures:
| Operating Temperature | Hastelloy C22 | Hastelloy C276 |
|---|---|---|
| Up to about 1250°F (677°C). | Suitable for temperatures up to 1250°F (677°C). |
Weldability
| Weldability | Hastelloy C22 | Hastelloy C276 |
|---|---|---|
| Excellent weldability using standard techniques, minimal risk | Good weldability using conventional methods, requiring | |
| of weld decay. | proper post-weld heat treatment to maintain corrosion | |
| resistance. |
Hastelloy C22 and C276 Applications
| Applications | Hastelloy C22 | Hastelloy C276 |
|---|---|---|
| Chemical Processing | Used in reactors, distillation columns, heat exchangers | Widely used in chemical processing environments, |
| including reactors and piping systems. | ||
| Pulp and Paper | Digesters, bleach plants, evaporators | Bleach plants, digesters, and other pulp and paper |
| production equipment. | ||
| Pharmaceutical | Pharmaceutical reactors and equipment | – |
| Oil and Gas | Equipment for sour gas wells, offshore platforms | Downhole and surface equipment in oil and gas production |
| environments. | ||
| Waste Treatment | Pollution control systems, scrubbers | Waste treatment plants and pollution control systems. |
| Aerospace | – | Used in aerospace applications where corrosion resistance |
| and high strength are critical. |
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅ Over 18 years of export experience, products sold to more than 80 countries
✅ Certified by ISO, SGS, and BV
✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars
✅ Custom processing services available – including cutting, polishing, CNC machining, and packaging
✅ Fast delivery within 7-15 days, supported by global logistics partners
📦 Packaging and Shipping
All stainless steel products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
About Gnee Steel
Gnee Steel is a professional manufacturer of nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy 800, Incoloy 800H/HT, Incoloy 825, Monel 400, Monel K500, and other high-temperature alloy materials. We specialize in the production and sales of alloy materials. Gnee Steel's products are widely used in aerospace, chemical, power generation, automotive, nuclear energy, and other fields, and we can provide customized alloy material solutions according to customer needs. For inquiries about alloy material prices or customized alloy material solutions, please feel free to contact us via email at ss@gneemetal.com for a quote.
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