Case Study: Circular Partnership

Since 2010, SIJ Acroni, a leading steel producer, and Hidria, one of the leading providers of sustainable automotive and industrial technologies, have cultivated a collaborative partnership. This partnership exemplifies innovation, efficiency, and environmental stewardship in the production and application of electrical steel. Through the supply of SIJ Acroni’s SIWATT non-oriented electrical steel and the efficient recycling of steel waste, the two companies demonstrate how industrial collaboration can drive sustainable practices.

SIWATT Electrical Steel: A High-Performance Material

SIWATT, a non-oriented electrical steel produced by SIJ Acroni, is needed for transmitting electrical energy and enables the comforts of modern life in an economical and increasingly eco-friendly way. Thanks to its excellent magnetizing properties and low core losses SIWATT is the perfect material for the production, conversion, and use of electricity. And the driving force behind green mobility.

SIJ Acroni supplies Hidria with SIWATT steel in the form of steel coils with dimensions of 1000 mm width and 1300 mm diameter. Hidria utilizes these coils to manufacture laminations – in a rapid-stamping process by forming electrical steel with a thickness of between 0.3 and 1 mm. These laminations form the core of stator and rotor packages, which are integral to electric motors used across industries, including automotive, aerospace, medical technology, and energy supplies. 

Hidria’s electrical steel laminations are used in various segments of the automotive industry – for example, for drive motors for electric and hybrid vehicles, steering systems, pumps, heating, cooling and air conditioning systems.

Closing the Loop

During the lamination production process, the stamping of steel inevitably generates waste. Instead of discarding this scrap, Hidria returns  it to SIJ Acroni, where it is remelted and used in the production of new steel. The proximity of the SIJ Acroni and Hidria plants – less than a kilometer apart – means that this process involves almost zero transport and, consequently, negligible transport-related emissions. This closed-loop system minimizes landfill waste and ensures the material is reused efficiently, reducing the environmental impact of both companies.

The SIWATT Production Process

SIWATT steel is produced through a meticulously controlled process to ensure quality and performance. Recycled steel scrap is melted in an Electric Arc Furnace (EAF), alloyed in a ladle furnace, and refined in a VOD converter. Chemical analysis is conducted at each stage to ensure quality control. The heat is cast on the continuous casting machine and cut into slabs, reheated in a pusher type furnace and rolled in the hot rolling mill, progressing through roughing and reversible finishing mills to form hot rolled coils. The coils are side trimmed, shot blasted, and cold rolled to the desired thickness. On the annealing and coating line the strip is cleaned and travels through the annealing furnaces which enables decarburization, recrystallization annealing, and crystal grain growth to ensure the required final magnetic properties. The strip is then coated with an insulating varnish, slit into strips of the desired width and packed into protective packaging.

Life Cycle Assessment: Sustainability at the Core

SIJ Acroni’s SIWATT steel is manufactured from 97% recycled steel scrap and 3% alloying elements, using no iron ore. Low Scope 1 emissions are largely due to the use of Electric Arc Furnace (EAF) technology, which is inherently more sustainable compared to traditional steelmaking methods. Furthermore, we have introduced a sustainable line of SIWATT steel produced entirely with renewable energy. This lowers the carbon footprint by 25%, reducing CO₂ emissions from 0.925 tons to 0.689 tons per ton of finished product.

Conclusion

The partnership between SIJ Acroni and Hidria exemplifies how industrial collaboration can achieve both operational excellence and environmental sustainability. By supplying SIWATT electrical steel and recycling production waste, the two companies have created a closed-loop system that minimizes waste, conserves resources, and reduces carbon emissions.