CSP Nexus: A new era

Decarbonization, digitalization, and flexibilization – these three important future trends define the transformation of the steel industry. Yet with what technology and strategy? Following the revolutionary invention of CSP technology with integrated casting and rolling by SMS, CSP Nexus is the next big thing. This is far more than just a technological enhancement. With CSP Nexus, SMS group is setting standards in efficiency, flexibility, and sustainability. This technology is opening up entirely new perspectives. Whether it is changing demands in volatile markets, reducing the ecological footprint, fully exploiting the possibilities of digitalization, or optimal flexibility – CSP Nexus combines all of these.

It was a revolution in steel strip production: In 1989, the first compact strip production plant, CSP for short, went into operation at Nucor in Crawfordsville, USA. The idea of combining continuous casting and rolling in a compact plant to produce high-quality strip saves owners significant investment and operating costs. Utilizing the casting heat directly for the downstream rolling process, however, not only reduces energy costs: Over the decades, since CSP plants have been in operation, enormous amounts of CO2 have been saved around the world. And CSP Nexus is the next step in decarbonizing the metals industry.

CSP Nexus is already implemented in practice, and further commissioning projects are soon to be completed. Orders from three different continents from Steel Dynamics, H2 Green Steel, and JSW Steel impressively demonstrate the global relevance of the concept, but also its flexibility. That is because customers have different strategic focal points when it comes to the way they utilize their plants.

Despite the differences between the reference facilities, the technological basis is the cornerstone of the success of CSP Nexus. Key features include:

• A caster with a throughput of 8 t/min and more
• The decoupled rolling process with additional powerful roughing mill stands
• A flexible furnace concept that is operated with natural gas, hydrogen, or electricity alone

The greatest advantage of CSP Nexus is the “real batch” rolling process in which, similar to conventional hot strip mills, roughing and finish rolling are two separate phases. To keep as much heat in the process as possible, two or three powerful roughing stands enable roughing to take place at the highest speeds. This means that energy consumption is reduced further, and operating costs are therefore lower. Not only that, the product mix can be expanded to include products with high added value, such as thin-gauge, high-strength grades for automotive applications. At the opposite end of the spectrum, heavy-gauge HSLA for line pipes or wind turbine construction, can also be covered with CSP Nexus, as it features a process that is capable of fully utilizing real thermomechanical rolling. Only the complete separation of the roughing and finishing phases provides maximum flexibility when it comes to controlling the material speed, temperature, and time profile from the moment it leaves the caster until it reaches the downcoiler.

The H2 Green Steel project in Boden, Sweden, marks a major milestone in the steel industry as Europe’s first near-zero carbon steel plant. The core element of downstream production is the CSP Nexus plant. H2GS will be able to produce a wide range of products, including high-strength steels and demanding automotive steel grades. The special feature here: The new plant relies entirely on electricity as the sole source of power for the heating processes. This is where a combination of resistance heating furnaces is used that ensure a uniform temperature level throughout. The concept is complemented by inductive heating modules that are only purposefully activated to meet the specific requirements of the final products.

To make production on the CSP Nexus plant as energy-efficient as possible, SMS introduced the X-Pact Integrated Process Model into the plant’s level 2 automation system, in order to coordinate the conventional level 2 models such as X-Pact Pass Schedule Calculation (PSC) or X-Pact Cooling Section Control. The integrated process model takes into account the whole process including the entire temperature progression until the strip is finally wound on the coiler. Depending on the production plan and the desired mechanical properties, therefore, the furnace temperatures can be set as low as possible.

For JSW Steel (Dolvi Works), the CSP Nexus plant in India is opening up entirely new perspectives in terms of energy efficiency and productivity. For the first time, it will be possible to produce both hot strip in conventional strip sizes as well as in widths and thicknesses of plates on a single plant for use in shipbuilding or wind turbine construction, or for API tube grades, for example. With thicknesses ranging from 2 to 32 mm and maximum widths of up to 2,600 mm, the CSP Nexus for JSW’s Dolvi plant offers a previously unmatched level of flexibility in the product portfolio.

The plant boasts a maximum annual capacity of 4 million t with provision of additional 3 million t by adding a second casting strand in future. JSW Steel is able to venture into new market segments under attractive conditions, particularly into the growing markets for green, sustainably manufactured steel products.

Alongside numerous process control systems and process models, X-Pact Centerline Control provides integrated strip flow control that ensures the stability of the rolling process in the finishing mill and helps to meet the challenges of autonomous rolling.

CSP technology is not new to JSW Steel. For many decades, JSW Steel and SMS group have enjoyed a long-standing partnership and cooperation: In 1998, for example, the first CSP plant in India was put into operation at JSW’s Dolvi plant. Since then, the plant has been consistently setting benchmarks in terms of productivity and quality through continuous upgrades and enhancements. With a production volume of 313,007 t of CSP hot strip in October 2023, Dolvi achieved the highest monthly production rate ever, surpassing its own record from 2022.

SMS group has developed suitable service models for the CSP Nexus that ensure that plant owners benefit from the latest technologies, in particularly from digital innovations. The range of products and services extends from servicing and maintenance, through spare parts service, to digital twins and technical consulting.

By employing advanced digital tools such as predictive maintenance and remote support, CSP Nexus operators can ensure maximum availability and performance from their plants. This not only strengthens their competitiveness, but also helps to support industries on their way to a more sustainable future.

Automation and digitalization at the highest level open up a wide range of possibilities for the efficient operation of entire plant complexes in a highly dynamic, resource-efficient manner. Operators can monitor and control individual machines or all the units in a plant complex from centralized, local, or even external operator stations. Sophisticated process models, AI analytics, and intelligent tools for communication and plant visualization in real time work together to provide an integrated solution for intelligent manufacturing and autonomous plant operation. Thanks to a uniform software and automation ecosystem, automation and digital applications communicate smoothly, sharing data and information. Supplementary software can easily be added or customized. Hence, the integration risk is reduced to a minimum. Plant operators can focus on value-adding core aspects of their business, strategic objectives, or the development of their processes and products.

SMS group develops new partnership-based business models that go beyond traditional spare parts and repair services, with the aim of being a lifecycle partner offering integrated analog and digital solutions to optimize plant performance. These models aim to ensure continuous improvement and enhancement and include long-term subscriptions, with SMS group assuming comprehensive operational and process responsibility.

The new CSP Nexus systems at SDI, H2 Green Steel, and JSW Steel represent significant progress and mark the beginning of a new era of efficiency, flexibility, and sustainability. These first plants illustrate SMS group’s commitment to developing technologies that are not only energy-efficient but also fully carbon-neutral. Today, they already give us a taste of what the future of strip and plate production holds.

The CSP Nexus technology shows that it is possible to revolutionize even established production processes. Furthermore, the integration of digital solutions enables high-precision monitoring and control of the production process. These digital tools play a decisive role in increasing the overall efficiency of a plant.