When it comes to high-performance metal alloys that thrive in aggressive environments, Hastelloy stands out as a leader. Known for its exceptional corrosion resistance and mechanical durability, Hastelloy has found its place in demanding industries such as chemical processing, marine, aerospace, and power generation.
This article explores the composition, types, properties, and applications of Hastelloy, answering the common question: What material is Hastelloy? If you’re a material specialist, procurement engineer, or project manager evaluating advanced alloy solutions, this comprehensive guide will provide the clarity you need.
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What is Hastelloy?
Hastelloy is a registered trademark of Haynes International Inc., referring to a family of corrosion-resistant metal alloys primarily composed of nickel, with varying amounts of molybdenum, iron, chromium, cobalt, and other elements. These alloys are engineered for exceptional resistance to oxidizing and reducing agents, making them ideal for highly corrosive chemical environments.
Hastelloy is not a single alloy, but rather a group of alloys, each designed to meet specific industrial challenges.
Common Types of Hastelloy Alloys
1. Hastelloy C-22 (UNS N06022)
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Composition: Ni-Cr-Mo-W
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Notable for: Superior resistance to pitting, crevice corrosion, and stress corrosion cracking
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Applications: Chemical processing, pollution control, pulp and paper, marine industries
2. Hastelloy C-276 (UNS N10276)
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Composition: Ni-Mo-Cr-Fe
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Notable for: Excellent resistance to strong oxidizers and a wide range of acids including hydrochloric and sulfuric acid
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Applications: Heat exchangers, reactors, evaporators, flue gas scrubbers
3. Hastelloy B-2 (UNS N10665)
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Composition: Ni-Mo
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Notable for: Outstanding resistance to hydrochloric acid at all concentrations and temperatures
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Applications: Chemical reactors, pickling systems, pressure vessels
4. Hastelloy X (UNS N06002)
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Composition: Ni-Cr-Fe-Mo
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Notable for: High-temperature strength and oxidation resistance
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Applications: Aerospace engines, furnace components, and gas turbines
Chemical Composition of Hastelloy
While exact compositions vary, Hastelloy alloys typically contain:
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Nickel (Ni): Base element, offers corrosion resistance
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Molybdenum (Mo): Improves resistance to reducing acids and localized corrosion
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Chromium (Cr): Adds protection against oxidizing agents
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Iron (Fe): Adjusts mechanical properties and cost
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Cobalt (Co) and Tungsten (W): Present in some grades for added strength and corrosion protection
Mechanical Properties of Hastelloy
| Property | Typical Range (varies by grade) |
|---|---|
| Tensile Strength | 690 – 900 MPa |
| Yield Strength | 280 – 400 MPa |
| Elongation | 40 – 55% |
| Hardness (HB) | 150 – 220 |
| Density | ~8.9 g/cm³ |
| Melting Point | ~1320 – 1390°C |
These values may differ depending on the specific Hastelloy grade and heat treatment condition.
Key Characteristics of Hastelloy
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Excellent corrosion resistance in harsh chemical environments
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Outstanding performance in both oxidizing and reducing agents
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Superior resistance to pitting and crevice corrosion
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High-temperature and pressure capabilities
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Good weldability and formability
These characteristics make Hastelloy a reliable choice in applications where failure is not an option.
Industrial Applications of Hastelloy
1. Chemical Processing Plants
Hastelloy alloys are widely used in reactors, vessels, piping, and heat exchangers due to their resistance to acids, chlorides, and oxidants.
2. Marine Engineering
Used in seawater cooling systems, pumps, and marine exhaust systems where both corrosion and stress are critical challenges.
3. Power Generation
Essential in nuclear reactors and geothermal plants due to its ability to withstand extreme environments over long durations.
4. Aerospace Industry
Hastelloy X is particularly suitable for high-temperature parts in jet engines and turbines.
5. Pharmaceutical and Food Processing
Because of its resistance to contamination and ease of sterilization, Hastelloy is used in hygienic piping systems and reactors.
Comparison: Hastelloy vs Stainless Steel
| Feature | Hastelloy | Stainless Steel |
|---|---|---|
| Corrosion Resistance | Superior, especially in acids | Good, but limited in harsh acids |
| Cost | Higher | More economical |
| Temperature Resistance | Excellent | Moderate to high (varies by grade) |
| Mechanical Strength | High (especially in high-temp) | High, but can degrade over time |
| Weight | Slightly heavier | Lighter (depending on grade) |
Hastelloy is preferred for extreme conditions where corrosion resistance is the top priority, while stainless steel is suitable for less aggressive environments.
Fabrication and Machining
Although Hastelloy is more difficult to machine than standard stainless steel due to its strength and work-hardening characteristics, it can be successfully machined and welded with proper tools and procedures.
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Welding: Typically done using TIG or MIG welding with Hastelloy filler wire
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Forming: Cold or hot forming is possible, but cold forming may require intermediate annealing
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Machining: Requires slow speed, high feed, and rigid tools to avoid work hardening
Certifications and Standards
Hastelloy materials are supplied in compliance with major international standards such as:
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ASTM B575 (for plate, sheet, and strip)
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ASTM B619/B622 (for seamless and welded pipe)
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ASME Boiler and Pressure Vessel Code
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NACE MR0175 (for sour service in the oil and gas industry)
Conclusion
So, what material is Hastelloy? Simply put, Hastelloy is a family of high-performance nickel-based alloys engineered for extreme resistance to corrosion, high temperatures, and mechanical stress. It offers unparalleled reliability in aggressive environments, making it a top choice in critical industries around the world.
Whether you’re sourcing materials for a chemical plant, marine project, or aerospace component, choosing sasaalloy as your Hastelloy supplier ensures certified quality, excellent machinability, and reliable performance.
For more information or to request a quote, contact sasaalloy—your trusted partner in high-performance alloy solutions.
Post time: Aug-01-2025