SSAB, a global leader in steel manufacturing, has awarded SMS group for their sustainable steel production project in Luleå, Sweden. This project marks a significant step towards sustainable steel production, underscoring SSAB's commitment to fossil-free technologies and processes. SMS group will provide highly advanced technology solutions for the new cold rolling complex, covering a pickling line/tandem cold mill with CVC® technology, a continuous galvanizing line, a continuous annealing and galvanizing line, a recoiling and inspection line, along with major auxiliary plants like acid regeneration plant, roll shop, coil logistics and water treatment plants – key components to achieve the final quality of SSAB's specialty products. The project places great emphasis on a high degree of automation, with a focus on optimized operational processes, including efficient material flows and streamlined logistics. With an annual production capacity of approximately 1.3 million tons, the new complex will enable SSAB to serve the growing demand for 3rd generation advanced high-strength steel grades (AHSS), particularly serving the automotive sector. The cold rolling complex will be capable of processing strip widths up to 1,900 mm and thicknesses ranging from 0.4 mm to 2.5 mm, ensuring versatility in product offerings.
Pickling line / Tandem cold mill
Focusing on optimal strip quality in conjunction with low operational costs and SSAB’s sustainability goals, the pickling line / tandem cold mill (PL/TCM) concept was developed in close collaboration between the technical experts of SSAB and SMS group. Exemplary for the lived partnership stands the commonly executed and evaluated pickling trials of 3rd gen. AHSS to support the selection of the pickling section concept with SMS group’s turbulence pickling technology.
The X-Pact® Turbulence Pickling Model maximizes productivity while minimizing energy and acid consumption. The model meets the requirements for optimal strip surface quality, minimized excessive pickling, thus lowering maintenance and operating costs. The sustainability of the pickling process is significantly enhanced through a fossil-free regeneration process of the hydrochloric acid through a hydrogen fueled acid regeneration plant (ARP).
Based on both companies’ long-term experience in cold rolling with different mill stand technologies, selection was made for SMS group’s unique CVC® plus 4-high technology (Continuous Variable Crown). Cold rolling of 3rd gen. AHSS is characterized by high specific rolling forces (kN/mm). Therefore, to avoid that roll contact pressure is reaching critical levels, which could cause among others spalling of work rolls, the use of 4-high mill stands is the right solution. Furthermore, the operational costs for purchasing and grinding of rolls, as well as the indirect carbon emission footprint caused by the roll manufacturing process is sustainably reduced. The high stiffness of the 4-high mill stands in combination with a new machine learning feature for predicting the best presetting for thickness control, considering the relevant incoming hot strip material data, will ensure to comply with SSAB’s high demands towards closest thickness tolerances across the strip width.
Additionally, SMS group will supply the roll shop to ensure optimal roll eccentricity and surface texture for superior strip surface quality. An automatic roll loader and roll shop management system provides a high degree of automation.
A range of sophisticated process automation models and functions, along with enhanced assistance systems, control the process fully automatically and guarantee high plant efficiency. X-Pact® Pass Schedule Calculation (PSC®) as a self-optimized process model predicts rolling forces, speeds, temperatures, and gauges for the cold rolling process. X-Pact® Superior Control determines the optimal strategy for executing product changes. Utilizing an advanced AI approach, it reduces off-gauge lengths, thereby increasing yield during product transitions.
The Genius CM® Chatter Plus condition monitoring detects and prevents chattering in the cold rolling process, thereby preventing strip breaks and avoiding thickness fluctuations. The Width Offset Minimizer reduces the scrap and ensures the perfect strip positioning within the PL/TCM.
Annealing and galvanizing technology
To achieve optimal surface quality, SMS group will deliver two outstanding galvanizing lines: a continuous galvanizing line (CGL) and a combined continuous annealing and galvanizing line (CAL/CGL). Both lines are equipped with fully electrically heated Drever furnaces, which utilize a combination of induction heating and electrical powered radiant tubes, thus ensuring a minimal carbon footprint. This advanced furnace design ensures precise control of the annealing process, optimizing the microstructure of the steel strip. The advanced atmosphere control prepares the strip surface for best metal coating results. The AI-fueled X-Pact® Microstructure Property Model enhances production by using data-driven models that predict material properties and allow specific adjustments during the production process.
For optimal surface quality, both lines will be equipped with Duma-Bandzink air knive systems, which precisely control the coating thickness and ensure uniform application across the strip. Various coatings, including Zinc-Magnesium (ZnMg) for the CGL and Aluminum-Silicon (AlSi) for the CAL/CGL, meet diverse corrosion protection needs, allowing SSAB to meet specific market requirements. Both lines have a strip width range of 900 to 1,900 mm and can handle thicknesses from 0.4 to 2.5 mm, with a capacity of approximately 650,000 tons per year and a process speed of 180 m/min.
Following the coating application, the recoiling and inspection line (RCL) plays an important role in ensuring final quality assessment and efficient operations with inspection section. An integrated welding section gives the capability to cut and connect coils.
Innovative technologies for efficient production and digital integration
SSAB’s new facility will be equipped with a digital twin for process optimization and condition-based maintenance of the equipment to ensure efficiency, sustainability, and reliability. The high level of automation ensures seamless operations and minimal human intervention, achieving optimal performance and resource efficiency.
SMS group will supply the complete electrical and automation systems including a comprehensive power supply package featuring transformers and sub-distribution systems, as well as the complete drive systems package including X-Pact® Torque Drives specifically tailored to SSAB's plant requirements.
Besides the complete X-Pact® level 1 and level 2 automation, the scope of supply encompasses technological measuring devices and smart sensors for maximum efficiency and process stability of the plant complex.
As a centralized data platform, the SMS DataFactory collects all data and signals from the plant and its automation systems. This ensures digital readiness and enables the comprehensive integration of digitalization across all SSAB locations. SMS group further equips the facility with digital solutions enabling real-time data analysis and data-driven proactive decision-making, improving overall plant performance.
To enhance operational efficiency, SMS group will supply AMOVA robotics applications and logistics systems that optimize material flows and streamline logistics processes within the new cold rolling complex. These systems include advanced functionalities such as automatic debanding of coils, strapping, and coil marking in the coil handling areas of the strip processing lines.
This project underscores the trusted partnership between SSAB and SMS group. Together, we set new standards for sustainable steel production and technological innovations.
