Discover Empyrean, the all-in-one solution for green steel analysis

by Uwe König, Thursday, 29th August 2024

Engineer inspection on hole rolls of metal carbon steel sheets

As governments and industries look to reduce carbon emissions and thereby reach their net-zero targets, steel production is under increasing scrutiny. Indeed, a majority of steel is still made in coal-fired blast furnaces. However, a revolutionary new steel-making process is set to transform the industry: using hydrogen instead of coal to produce ‘green steel’.

While the first large-scale green steel plant – H2 Green Steel – is expected to start producing this low-carbon emissions steel in late 2025, manufacturers are also looking to convert their existing processes to this much more sustainable method. However, a new production process means new analytical solutions are required to ensure green steel meets the quality criteria required by its users.

How do manufacturers measure the quality of their steel?

Correctly defining the quality of the output needs to be accurate and fast to avoid producing large amounts of sub-standard steel. Manufacturers therefore check several parameters to rapidly and reliably assess the quality of steel samples. These include:

  • Retained Austenite: When iron is melted into steel, it passes into what is called an austenite phase. In this phase, carbon atoms diffuse rapidly. When cooled, steel enters the much more stable and harder martensite phase. As the continued presence of austenite can significantly compromise the stability of hardened steel, manufacturers check that the amount of retained austenite is as low as possible (typically <2%).
  • Size and strain: Like practically all metals, steel is a polycrystalline material: it is composed of many small crystals, which are atoms formed into highly ordered microscopic structures called lattices. The sizes of these crystals and variations in the lattices, known as microstrains, influence steel properties such as stability and elasticity.
  • Texture: This indicator reflects how the crystals in steel are oriented: these orientations can be fully random, or have some preferred orientation to a weak, moderate, or strong degree. Assessing texture is vital as it determines many physical properties of steel such as hardness, elasticity, conductivity, thermal expansion, and mechanical wear. 
  • Residual stress: These are stresses that remain in steel even when the original cause of the stress has been removed. The steel-making process involves many such stresses, both internal and external. Assessing residual stress in steel is crucial in evaluating its stability and overall quality.

Manufacturers might choose to invest in a dedicated instrument to measure each of these parameters. However, each additional instrument means more sample preparation, more training for operators, and more bottlenecks – all adding to extra costs. Instead, all these key parameters can be measured with a single instrument: the Empyrean X-ray diffraction (XRD) platform.

Why the Empyrean is ideal for the steel manufacturing context

To keep up with the needs of a fast-paced and high-standards production environment, analytical instruments need to provide fast and accurate analysis –  but that’s not all.

Indeed, steel manufacturers have only just begun developing and implementing more sustainable production processes, so the effects of these processes aren’t completely known. To accompany the steel industry’s evolving analytical needs, instruments need to have the flexibility to provide different kinds of analysis and for different kinds of samples.

The Empyrean XRD is one such solution. Indeed, XRD instruments require little to no sample preparation. Not only does this save time, but it also means that almost any sample size and shape can be analyzed easily, whether it’s the raw materials or the steel itself. XRD is also non-destructive – an analyzed sample can be re-analyzed with a different instrument or even returned to the production line.

Empyrean’s great advantage for steel analysis is that it can provide fast analysis for all the parameters listed above, within a single instrument. This allows the operator to switch between measurement methods easily, within minutes, and with minimum interaction.

Supporting the future of steel

With the Empyrean, steel manufacturers therefore have a highly flexible instrument that can quickly and reliably assess the quality of their steel. In combination with dedicated software packages, most analyses can even be automated and digitalized. The Empyrean is therefore a future-proof solution, ready to support the steel industry’s transition to green steel manufacturing!

If you’d like to learn more about the application of Empyrean to steel analysis, read the steel and alloys analysis application note!

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