Exploring Nickel Power: Key Applications Across Diverse Industries
Introduction
Nickel (Ni) is a chemical element and ferromagnetic metal of the periodic table’s Group 10 (VIB). It is markedly resistant to oxidation and corrosion. It is Silvery white, challenging, and more complex than iron. Nickel is widely familiar because of its use in coinage. It is essential either as a pure metal or in the form of alloys for its many domestic and industrial applications. Elemental nickel very sparingly occurs together with iron in terrestrial and meteoric deposits.
Nickel Properties
Element Properties | |
atomic number | 28 |
atomic weight | 58.69 |
melting point | 1,453 °C (2,647 °F) |
boiling point | 2,732 °C (4,950 °F) |
density | 8.902 (25 °C) |
oxidation states | 0, +1, +2, +3 |
electron configuration | [Ar]3d84s2 |
Nickel will readily be alloyed with many other metals, including chromium, iron, molybdenum, and copper. This allows for a wide variety of alloys demonstrating outstanding resistance to corrosion and high-temperature scaling, exceptional high-temperature strength, and other unique properties, such as shape memory and low coefficient of expansion.
The following is a simplistic categorization of the various nickel alloy types.
Wrought Nickel
Pure nickel UNS N02200 is used in the chemical industry for its corrosion resistance – particularly to alkalis. It is also used for its properties in shielding against electromagnetic interference and transducers.
Nickel-Iron Alloys
Invar® (UNS K93600), which contains 36% nickel and the remainder iron, maintains an almost zero coefficient of thermal expansion around room temperature. Engineers use it where high dimensional stability is crucial, such as in precision measuring instruments and thermostat rods. Additionally, its meager thermal expansion rates make it ideal for use in cryogenic temperatures.
Alloys with 72-83% nickel exhibit the best soft magnetic properties, making them essential for applications in transformers, inductors, magnetic amplifiers, magnetic shields, and memory storage devices.
Nickel-Copper Alloys
These are highly corrosion-resistant by alkaline solutions, non-oxidizing salts, and seawater. The best-known is the Alloy 400.
Nickel-Molybdenum Alloys
These highly resist reducing acids without oxidizing ions, such as ferric, cupric, or dissolved oxygen. The best-known is Alloy B-2.
Nickel-Chromium Alloys
They resist corrosion at average and high temperatures (including scaling), exhibit high high-temperature strength, and maintain high electrical resistance. There are three main groups of alloys:
Ni-Cr (and also Ni-Cr-Fe) alloys with high electrical resistance for heating elements, such as 70-30 (UNS N06008) and C-Grade (UNS N06004)
Ni-Cr alloys (with Fe and other alloying elements) with good corrosion resistance. The best-known are Alloy 600 (UNS N06600) and Alloy 601 (UNS N06601)
Ni-Cr alloys with high-temperature strength and creep resistance, mostly age-hardenable, such as Alloy X-750 (UNS N07750)
Nickel-Chromium-Iron Alloys
There are two groups of alloys:
Ni–Cr–Fe alloys have excellent strength at high temperatures and can resist oxidation, carburization, and other types of high-temperature corrosion. The best-known is alloy 800 (UNS N08800) and its variants 800H (UNS N08810) and 800HT (UNS N08811). (Recently, these alloys were classified as stainless steels, reflecting their high Fe content)
Ni–Cr–Fe (with Mo and Cu) alloys with excellent corrosion resistance in specific applications. The best-known is alloy 825 (UNS N08825), which offers exceptional resistance to sulphuric acid. Alloy G-3 (UNS N06985) offers corrosion resistance to commercial phosphoric acids and many complex solutions containing highly oxidizing acids.
Nickel-Chromium-Molybdenum Alloys
These are highly corrosion-resistant, and Alloy C-276 (N10276) is the best-known. They offer exceptional resistance to reducing acids such as hydrochloric and sulphuric. Many variants based on this composition have modified the Cr and Mo levels and, in some cases, added Cu or W to extend the corrosion resistance to more oxidizing or reducing conditions. These include Alloy C-22 (N06022), Alloy 59 (N08059), Alloy C-2000 (UNS N06200), and Alloy 686 (N06686).
Nickel-Chromium-Cobalt Alloys
Adding cobalt and molybdenum imparts solid-solution strengthening and high levels of creep-rupture strength to alloy 617 (UNS N06617). Adding cobalt to HR-160 (N12160) provides outstanding resistance to various high-temperature corrosion attacks, such as sulphidation and chloride attacks in both reducing and oxidizing atmospheres.
Nickel-Titanium Alloys
55% nickel-titanium alloy (UNS N01555) (Nitinol) has shape-memory properties. When formed at one temperature and then deformed at a lower one, it regains its original form when reheated. The transition temperatures can be adjusted through careful control of the composition. Medical devices and specialized connectors are two of the specific applications. The same alloy can also undergo considerable elastic deformation and return to its original shape (super-elastic property). This property has been exploited for applications as diverse as spectacle frames and shock absorbers that provide earthquake resistance in historic stone buildings.
The nominal composition of various nickel alloys:
Alloy name | UNS | % Ni | % Cr | % Fe | % Mo | % Cu | % Co | % Other |
200 | N02200 | 99 min | ||||||
Invar | K93600 | 36 | 64 | |||||
400 | N04400 | 65 | 32 | |||||
B-2 | N10665 | 68 | 2 | 28 | ||||
70-30 | N06008 | 70 | 30 | |||||
C-Grade | N06006 | 60 | 16 | bal | ||||
600 | N06600 | 76 | 16 | 8 | ||||
601 | N06601 | 60 | 23 | bal | Al – 1.3 | |||
X-750 | N07750 | 70 | 15 | 7 | Ti – 2.5, Al – 0.7, Nb – 1.0 | |||
825 | N08825 | 42 | 21 | 25 | 3 | 2 | ||
G-3 | N06985 | bal | 22 | 20 | 7 | 2 | ||
800 | N08800 | 32 | 21 | 45 | W – 3.5 | |||
C-276 | N10276 | bal | 15 | 5 | 16 | |||
C-22 | N06022 | bal | 21 | 4 | 13 | |||
59 | N06059 | bal | 23 | 1.5 max | 16 | |||
C-2000 | N06200 | bal | 23 | Three max | 16 | 1.6 | ||
686 | N06686 | bal | 21 | Two max | 16 | W – 3.7 | ||
617 | N06617 | 44.5 min | 22 | Three max | 9 | 12 | ||
HR-160 | N12160 | bal | 28 | 3.5 max | 30 | Si – 2.75 | ||
Nitinol | N01555 | 55 | Ti – 45 |
Applications of Stainless Steel, Duplex Stainless Steel, Nickel-based Alloys
Alloy Type | UNS | %Cr | %Ni | %Mo | %Cu | %Fe | Features and Applications |
304L | S30403 | 18 | 8 | – | – | bal | The most common stainless steel is used for potable water treatment and food contact. |
316L | S31603 | 16 | 10 | 2.1 | – | bal | The addition of Mo provides excellent resistance to chlorides and acidic solutions. It is used in coastal regions, water treatment, and the chemical processing industry. |
2205 | S32205 | 22 | 5.7 | 3.1 | – | bal | Even more excellent corrosion resistance than 316L. It can be used instead of 316L, but its greater strength can reduce weight. It may be substituted for 316L if it fails in service. |
2507 | S32750 | 25 | 7 | 4 | – | bal | Even greater corrosion resistance than 2205. Useful corrosion resistance to seawater. |
254 SMO | S31254 | 20 | 18 | 6.1 | – | bal | Corrosion resistance is similar to 2507 and has useful corrosion resistance to seawater. |
Alloy 20 | N08020 | 20 | 33 | 2.1 | 3.2 | bal | Cu-bearing stainless steel with helpful corrosion resistance to all concentrations of sulphuric acid. |
310S | S31008 | 25 | 20 | – | – | bal | High chromium stainless steel with excellent resistance to high-temperature oxidation. |
800H | N08810 | 20 | 32 | – | – | bal | Stainless steel has excellent high-temperature strength and useful resistance to high-temperature oxidation. |
625 | N06625 | 21 | bal | 9 | – | 3 | Well-known nickel alloy with excellent high-temperature strength and outstanding aqueous corrosion resistance. |
C-276 | N10276 | 15 | bal | 16 | – | 5 | One of the best-known nickel alloys with excellent corrosion resistance to reducing acids. |
600 | N06600 | 16 | 76 | – | – | 8 | Proper resistance to high-temperature corrosion and caustic solutions. |
Alloy 400 | N04400 | – | 65 | – | 32 | – | The most common uses are in marine and chemical processing. |
Conclusion
Nickel’s versatility makes it indispensable across various industries, from aerospace and chemical processing to energy and electronics. Its corrosion resistance, high-temperature stability, and strength under pressure ensure its continued demand for critical applications. As industries evolve and new technologies emerge, nickel’s role in advancing performance and innovation remains pivotal. Understanding its applications is essential for companies aiming to optimize material selection and stay competitive in global markets.