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What are inoculants?

Enhancing and controlling nucleation in cast irons.

Inoculants are vital for avoiding metallurgical defects in cast iron caused by insufficient nucleation. Elkem offers an unbeaten range of premium inoculants, supplied globally, and our specialists will help you choose the perfect ones for your application.

Inoculants: Improving nucleation in cast irons

Prior to pouring of iron melts, ferrosilicon-based inoculants are added to control the process of solidification, and so provide the desired microstructure and mechanical properties in the iron casting. Inoculants work in two basic ways:

  • They increase the number of nucleation sites present prior to solidification, so providing a more uniform distribution of graphite particles with the desired structure.
  • They minimize undercooling of the melt (‘chilling’) below the metastable eutectic temperature, and so favor formation of graphite rather than cementite (iron carbide).

Inoculants are mostly added to the ladle or in-stream, but for some specialized applications they can be better added directly into the mold as inoculant blocks, known as inserts.

The role of size and chemistry

Although the impact of inoculants on production costs is very small, it is vital that they are selected carefully, because their performance has an enormous effect on metallurgical quality.

Elkem has pioneered the development of bespoke inoculant specifications for the worldwide iron foundry industry for many decades. We continue to be at the forefront in tailoring new chemical compositions and size specifications to meet the needs of our customers.

Premium-quality inoculants from Elkem

Elkem’s inoculants are premium products that contain carefully balanced amounts of active elements designed to control the microstructure and mechanical properties of a variety of cast iron compositions and castings. These include our flagship SUPERSEED™ inoculant – the most popular product of its kind for gray iron – as well as RESEED™ and ULTRASEED™ Ce inoculants for ductile iron.

Like our other foundry alloys, our inoculants are carefully manufactured to provide very high batch-to-batch consistency, eliminating worries over exactly what you’re getting.

With you at every step

We’re more than just a manufacturer of foundry alloys – talking to us is a collaboration. We’ll start by listening carefully to your product requirements, and then work out which specification will deliver maximum product quality and cost-effectiveness. And of course we’ll provide expert guidance and insight when you need it, throughout the whole production process.

Furthermore, we’re the only manufacturer of foundry alloys that offers a dedicated network of metallurgists, process engineers and research staff in all the major global regions, and with manufacturing facilities close to all the principal foundry clusters. So wherever you’re located, you’re guaranteed to get expert service and fast delivery of inoculants and other foundry alloys for manufacturing cast iron.

Sustainability at Elkem

To learn more about our sustainability initiatives, check our webpage.


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