SIJ Acroni, the largest company in the SIJ Group, and project partner C3M are participating in the research and development project (RRI) PETRA. The project is geared towards the transition to a circular economy, including the prevention and control of pollution.  It concerns the development of a new product with high added value and the optimization of the existing production programme with the aim of enhancing the material and energy efficiency of the manufacturing process.


Industrial partner SIJ Acroni and high-tech company C3M are participating in the project of optimization of the carbon footprint of steel with the digital twin of hot rolling (PETRA). The goal of the project is to roll out a new niche product to the market and to enhance the material and energy efficiency of the entire hot working process of low-alloyed niobium structural steel quarto plates.  In order to achieve the appropriate microstructure of the quarto plates during hot working, a digital twin will be developed, which will allow for more precise management of the entire hot working process. Doing so ensures the targeted microstructure of the quarto plates and consequently reducing the need for additional heat treatment or remanufacture of the end products. This leads to a significant reduction in energy consumption and, consequently, to a lower environmental impact.

The digital twin TMProSim (Thermomechanical and Microstructural Process Simulator) will be based on a coupled thermomechanical and microstructural model. The thermomechanical rolling model is based on the finite element method. The microstructural model RSProSim (Rolling Schedule Process Simulator) combines different physically designed models to describe the processes that occur in steels during their thermomechanical treatment and determine the evolution of the microstructure.

The implemented digital twin will contribute to the advanced, efficient and environmentally friendly development of high-value products and to the optimization of the technological path in the manufacture of steels, with the aim of material and energy efficiency of the entire hot working process of quarto plates. The project is ambitious and goes beyond the development and optimization of a group of structural quarto plates alloying with niobium.  It has a great potential for a wider range of uses, as the final model will be deployable when optimizing technological paths for other types of steels through the expansion of the material database.

The RRI project will improve the competitiveness of SIJ Acroni, which is part of the largest Slovenian steel company SIJ Group and contribute to the generation of knowledge and methods for the transformation of this sector from an energy- and environment-intensive industry to a knowledge industry and lead this industry towards Industry 4.0 and green steel.


Key project details:

Total value of project co-financing: EUR 263,291.56

Project duration: 2/11/2022 – 1/11/2024

Project website: www.noo.gov.si, www.evropskasredstva.si

Programme: Incentives for research and development projects of the National Recovery and Resilience Plan (RRP).

Lead Partner: SIJ Acroni, SIJ Group

Other partners: C3M

The investment is financed by the European Union - NextGenerationEU.


SIJ Group is a leading European producer of stainless and specialty steels. We are committed to achieving climate goals on a global and EU level, and operate according to the principles of circular economy. Our steels and our products establish us as a partner for Europe’s green transition. At the end of 2023, SIJ Group plans to become certified under the strict ResponsibleSteel standard, which will rank us among the world’s most responsible and sustainable steel producers. Our largest companies are modern recycling steel mills, and our steel is recycled, as it is produced from steel scrap. With a headcount of over 3,800, we are one of Slovenia’s largest employers and are a cornerstone of Slovenia’s steel sector. We rank among Slovenia’s leading exporters, as we generate approximately 85 percent of our total revenue on foreign markets.


Find out more at:

SIJ – Slovenska industrija jekla, d.d.

mag. Sara Wagner, Head of Corporate Communications

Corporate Communications

Phone: +386 1 242 98 27

Mobile: +386 41 313 532

E-mail: sara.wagner@sij.si