Nickel Alloys
Nickel alloys keep strength and resist corrosion and oxidation in extreme conditions, from high temperatures to aggressive acids and seawater. Families include Inconel (Ni-Cr), Monel (Ni-Cu), Hastelloy (Ni-Mo-Cr) and nickel-chromium resistance alloys.
What it is
Nickel's stable structure allows heavy alloying: chromium adds oxidation resistance, molybdenum adds resistance to reducing acids, copper adds seawater resistance, and elements like niobium and titanium add high-temperature strength.
These alloys are expensive and difficult to machine, so they are used where stainless steels fail.
Typical applications
- Gas turbine and furnace components
- Chemical process equipment
- Marine and offshore parts
- Heat treatment fixtures
- Oil and gas downhole tools
Materials & grades
- Inconel 600, 625, 718
- Monel 400, K-500
- Hastelloy C-276, C-22
- Nickel 200/201
- Incoloy 800/825
Points to consider
- Machining is slow and tool wear high; plan cost and lead time.
- Choose the alloy for the specific environment (oxidising, reducing, chlorides, temperature).
- Verify material with MTC and PMI for critical service.
- Welding requires matched filler and procedures.
Frequently asked questions
When should nickel alloys be used?
When stainless steels can't cope with the temperature, oxidation or corrosive environment.
What is the difference between Inconel, Monel and Hastelloy?
Inconel (Ni-Cr) excels at high temperature; Monel (Ni-Cu) in seawater and hydrofluoric acid; Hastelloy (Ni-Mo-Cr) in strongly corrosive chemicals.
Are nickel alloys hard to machine?
Yes, they work-harden and retain strength at cutting temperatures, so machining is slower and more costly.