Nickel Alloys
Nickel alloys are the highest-performing corrosion-resistant and heat-resistant metals in industrial use. Steel Dynamics UK stocks and processes the four main nickel alloy families.
Inconel (nickel-chromium super alloys for high-temperature service), Hastelloy (nickel-molybdenum for extreme corrosion), Monel (nickel-copper for seawater and reducing acids) and Incoloy (nickel-iron-chromium for elevated temperatures).
Nickel alloys are specified where standard stainless steels, duplex and super duplex reach their limits - in aerospace jet engines, nuclear primary circuits, chemical reactor internals, subsea wellhead components, offshore risers and high-temp components.
Hastelloy Nickel Alloys
Hastelloy alloys are nickel-chromium-iron-molybdenum alloys with great strength and oxidation resistance, often used in high-temperature environments. They are renowned for their corrosion resistance and are used in various high-stress industrial applications.
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C-22. Offers better resistance to uniform corrosion in oxidizing media than C-4 and C-276, and has excellent localised corrosion resistance.
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C-276. Exhibits good resistance to oxidising and moderately reducing corrosion, and has excellent stress corrosion cracking resistance.
Monel Nickel Alloys
Monel is a group of nickel alloys primarily composed of nickel and copper, with small amounts of other elements like iron, manganese, carbon, and silicon, offering good strength and corrosion resistance in marine and chemical environments.
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400 (Alloy 400): Known for its high strength and excellent corrosion resistance in a range of acidic and alkaline environments, and its ability to withstand seawater and steam at high temperatures.
Inconel Nickel Alloys
Inconel alloys are a family of nickel-chromium-based super alloys known for their resistance to oxidation and corrosion, especially in extreme environments. They retain strength over a wide temperature range, which is ideal for high-temperature applications.
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600: Solid solution strengthened, with good resistance to many corrosive substances and high-temperature environments
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625: Contains niobium for strengthening, which gives it high strength without the need for heat treatment
Incoloy Nickel Alloys
Incoloy alloys are a series of nickel-iron-chromium alloys known for their high temperature durability and exceptional corrosion resistance, particularly in aggressive environments. They are leaner nickel versions of the Inconel range, offering more economical solutions to corrosive and high-temperature environments.
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Alloy 800: Designed for high-temperature structural applications and has a high creep-rupture strength due to the close control of carbon, aluminum, and titanium.
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Alloy 825: Known for its exceptional resistance to very corrosive environments, it has excellent resistance to oxidising substances, pitting, crevice corrosion, sulfuric, and phosphoric acids.
200 Grade Nickel Alloys
Nickel 200 and Nickel 201 are two commercially pure wrought nickel grades with excellent mechanical properties and resistance to a range of corrosive environments.
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Nickel 200 (UNS N02200): It is 99.6% pure nickel which offers excellent resistance to corrosion by caustic alkalis and is used in food processing, synthetic fiber production, and other applications.
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Nickel 201 (UNS N02201): This is the low carbon version of Nickel 200 and is suitable for applications where extended exposure to high temperatures can lead to the formation of graphite. It’s used in caustic salt evaporators and electronic components.
Frequently Asked Questions
What are nickel alloys used for?
Nickel alloys are used where standard stainless steels cannot withstand the temperature or corrosion environment — typically aerospace jet engines, nuclear power, chemical reactors, subsea oil and gas, high-temperature furnaces and pollution control equipment. They combine high mechanical strength at elevated temperatures with outstanding corrosion resistance in aggressive chemical environments.
What's the difference between Inconel and Hastelloy?
Both are nickel-based super alloys but with different strengths. Inconel (nickel-chromium) is optimised for high-temperature strength and oxidation resistance, making it dominant in aerospace and elevated-temperature service. Hastelloy (nickel-chromium-molybdenum) is optimised for corrosion resistance in strong acids and aggressive chemical environments. Inconel 625 and Hastelloy C-276 have significant application overlap where both temperature and corrosion matter.
Which Inconel grade should I use?
Inconel 600 for general oxidation and corrosion resistance in air and mildly corrosive service. Inconel 625 for combined strength and corrosion resistance across chemical, marine and structural applications — the most widely specified nickel alloy. Inconel 718 for aerospace and structural applications requiring very high strength at temperature (achieved through precipitation hardening).
What is Hastelloy C-276 used for?
Hastelloy C-276 is the workhorse of the Hastelloy family — used across chemical processing (particularly acid service), flue-gas desulphurisation, pharmaceutical manufacturing, pulp and paper bleaching, and pollution-control equipment. Its combination of nickel, chromium, molybdenum and tungsten gives it broad-spectrum resistance to both oxidising and reducing acids.
Do you stock nickel alloys in the UK?
Yes. Inconel, Hastelloy, Monel and Incoloy in plate, sheet and other forms, held in our processing facility in Lancashire, cut to size and shipped nationwide.
Nickel alloys find applications in a wide range of industries, including aerospace, chemical processing, oil and gas, automotive, electronics, medical, and marine.
They are used in components such as valves, pumps, turbines, reactors, heat exchangers, and various other critical parts.
