Using Metal Alloys to Prevent Corrosion

Nickel-based metal alloys have excellent corrosion resistance properties. This makes them the material of choice for the construction of applications for many different industries. They are mainly used in aqueous environments, in things such as pumps, valves and piping systems.

NeoNickel’s technical staff will be delighted to supplement the following brief guide to nickel and its alloying elements with more specific information. Please get in touch to discuss specific alloy properties and to share in our experience of alloy applications, their service and their performance, so we can supply your best solution.

The properties of nickel

Pure nickel is very corrosion resistant, especially to a variety of reducing chemicals. Alloying it with chromium gives resistance to oxidation, leading to a broad variety of alloys, such as ZERON® 100, with optimal corrosion resistance in both reducing and oxidising environments.

Alloys based on nickel can tolerate more additional alloys than stainless steel and other iron-based materials, while maintaining good stability. This flexibility has led to the development of a variety of nickel-based alloys with multiple additional alloys, designed to be resistant to a host of different corrosive environments.

Many alloying elements can be joined with nickel to resist corrosion in a variety of environments, and all can be supplied by NeoNickel. The exact metal alloy that’s right for you depends on your circumstances, and there are many potential options.

Nickel gives alloys metallurgical stability:

  • Alloys have more thermal stability and weld better.
  • Resistance to reducing acids and caustics is heightened
  • Resistance to stress corrosion cracking – specially in chlorides and caustics – is increased.

It’s clear to say that the benefits of these alloys are unrivalled. It’s little wonder they are so widely used in aqueous applications.

The different alloying elements

The different alloying elements have an impressive set of properties, which you can see in our line cards.

Chromium

Resistance to oxidising corrosives and high temperature oxidisation. Sulfidation is also improved. Resistance to pitting and crevice corrosion is boosted.

Molybdenum

Resistance to reducing acids, pitting and crevice corrosion in environments containing aqueous chloride is improved. It increases high temperature strength.

Iron

Resistance to high-temperature carburising environments is improved and helps to control thermal expansion. It reduces alloy costs.

Aluminium

Encourages age hardening. Resistance to oxidation and heightened temperatures is improved.

Copper

Resistance to reducing acids – notably, non-aerated sulphuric and hydrofluoric – and to salts is improved. Added to nickel-chromium-molybdenum-iron alloys, it boosts resistance to hydrochloric, phosphoric and sulphuric acids.

Niobium (formerly known as Columbium)

Combines with carbon, and vulnerability to intergranular corrosion caused by chromium carbide precipitation (that stems from heat treatments) is reduced. It increases high temperature strength. Resistance to pitting and crevice corrosion is improved.

Tungsten

Resistance to reducing acids and localised corrosion is improved. Weldability and strength are both boosted.

Nitrogen

Metallurgical stability is heightened. It increases high temperature strength. Resistance to carburisation and sulfidation is also improved.

Many of these elements can be alloyed with nickel in different combinations, so a very broad range of corrosion resistant alloys is available to suit a wide variety of environments. Because of their metallurgical stability, these alloys can be fabricated and thermally processed without the risk of harmful consequences. Many alloys with a high nickel content can also be strengthened by hardening processes, precipitation hardening, dispersion strengthened powder metallurgy and carbide precipitations.

Corrosion resistant alloys for your business

Would you like to find out more about corrosion resistant metal alloys, and whether they are right for you?

The technical staff at NeoNickel will be happy to discuss your specific metal alloy requirements in more detail. Contact us today for more information.