Reviewed · 2026-08-13
Nickel Alloys
Nickel alloys combine nickel with copper, chromium, molybdenum, iron and strengthening additions to serve caustic, seawater, acid, oxidation, creep and high-strength duties that exceed ordinary stainless-steel capability.
Classification basis
Principal alloying system, corrosion mechanism, temperature-strength requirement and product specification
Five selection families separate pure-nickel alkali service, nickel-copper marine behavior, chromium-led oxidation resistance, chromium-molybdenum corrosion resistance and precipitation-strengthened superalloys.
A familiar grade name never replaces the governing product specification and certified documentation.01
Explore subcategories
Commercially Pure Nickel
This group is nickel-rich without the chromium or molybdenum systems used for broad oxidizing-acid resistance; do not treat Nickel 200 and 201 as condition-free substitutes at elevated temperature.
→Nickel alloysNickel-Copper Alloys
This family is selected around marine and reducing service; it does not provide the chromium-based oxidation resistance of Ni-Cr alloys or the broad acid range of Ni-Cr-Mo systems.
→Nickel alloysNickel-Chromium Alloys
This category is chromium-led for oxidation and general high-temperature resistance; severe reducing-acid service usually demands molybdenum-bearing Ni-Cr-Mo alloys.
→Nickel alloysNickel-Chromium-Molybdenum Alloys
Ni-Cr-Mo is not one interchangeable grade family: C-276, 22, 625 and related alloys have different chemistry, code coverage and resistance envelopes.
→Nickel alloysNickel-Base Superalloys
This category is strength- and creep-led rather than simply corrosion-led; alloy, melt route, product form, grain structure and heat treatment are inseparable procurement variables.
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Representative grades and systems
| Grade / system | Use as a selection entry point |
|---|---|
| Nickel 200 / N02200 | Define full chemistry, contaminants, temperature and flow before alloy name. |
| Alloy 400 / N04400 | Use UNS plus exact product standard and condition. |
| Alloy 600 / N06600 | Qualify fabrication, filler metal and heat treatment with service exposure. |
| Alloy C-276 / N10276 | Define full chemistry, contaminants, temperature and flow before alloy name. |
| Alloy 718 / N07718 | Use UNS plus exact product standard and condition. |
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Property framework
Environment-specific corrosion resistance
Oxidation and carburization resistance
Strength, creep and metallurgical stability across temperature
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Common product forms
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Applications
- Chemical process equipment
- Marine, offshore and pollution-control systems
- Furnace, power-generation and aerospace components
- Define full chemistry, contaminants, temperature and flow before alloy name.
- Use UNS plus exact product standard and condition.
- Qualify fabrication, filler metal and heat treatment with service exposure.
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Standards and designation systems
UNS designation context
ASTM B-series standards by alloy and product form
Applicable ASME construction and welding qualification rules
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Procurement checklist
- State UNS, product specification and form.
- Define solution anneal or age condition and mechanical tests.
- Specify corrosion, PMI, NDT, surface cleanliness and certification.
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Sources and editorial review
Nickel Institute · Technical overview, accessed 2026
Nickel Institute · Technical Guide 11012, revised edition
Nickel Institute · Technical Guide 393, 2021