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Magazine13 Min

Pioneering solutions

1989: We invent CSP® technology

Can a company exist for 150 years without innovating? Of course not. Which is why in this episode, we take a look at some of our inventions that have transformed the world of metals. And we give an insight into how we are working on innovations for tomorrow’s world.

It is the summer of 1989, in the middle of cornfields at the edge of the small American town of Crawfordsville, when SMS and Nucor come together to write history: they put the first thin slab casting-rolling plant into operation. The newly developed funnel-shaped copper mold and the optimized submerged entry nozzle make “near-net-shape slab casting” possible. The slabs, just 50 millimeters thick, pass through a short tunnel furnace before being directly rolled down to their final dimensions in a finishing mill. As a result, the energy-intensive slab reheating and prerolling processes are no longer required. The name of this new technology? Compact Strip Production, or CSP® for short.

At that time, six years had already passed since the inventor’s flash of inspiration. Yet the road to a product’s market maturity is long. In 1985, working in total secrecy, SMS builds a test facility in its own foundry in Kreuztal, where it puts this new process to the test. Yet finding the first customer for the revolutionary plant concept proves to be just as difficult. All the established steel producers pass on the idea, until US-based Nucor decides to take a chance on it. And this courageous step pays off: Despite a stagnating US steel market, the plant is commercially successful right from the outset, thanks to its low manufacturing costs.

Every new CSP® plant brings with it a further enhancement of the technology. Before long, CSP® customers are producing strip for the automotive industry, high-strength grades, and tube steels. At the same time, we expand our product range to include ultrathin (down to 0.8 millimeters) and thick strip (up to 25.4 millimeters). The latest stage in the development of this technology is CSP® Nexus, which offers even higher productivity, greater flexibility, and the opportunity to produce hot strip in a carbon-neutral way.

CSP® pilot plant at SMS foundry in Kreuztal
Celebrating successful casts on the test plant.
CSP - Compact strip production
The breakthrough: The first CSP® plant at Nucor Crawfordsville (1989)
It's all about teamwork. Commissioning of the CSP plant at ACME, USA (today Cleveland Cliffs)
Maanshan Iron & Steel: One of seven CSP® plants supplied to China and the first ready for semi-endless rolling.
Ten years after the first plant, CSP® was fit for integrated steelmakers such as ThyssenKrupp Steel.
Very early, CSP® plants come along with SMS group's X-Pact® electrics and automation.
CSP® Nexus - the latest stage of CSP® evolution.

Concast means Continuous Casting

CSP® technology would be unthinkable without the development of the continuous casting process that came before it – another invention of the SMS family. The first industrial continuous casting plant for steel to feature an oscillating mold is developed in the 1950s by American metallurgical engineer Irving Rossi. In contrast to the hitherto common process of pouring portions of molten metal into permanent molds, the continuous casting of steel to produce slabs or billets provides for significantly higher productivity and quality levels. This is not limited to the casting process itself but also to hot rolling, as the upstream ingot and billet mills, customarily used up until then, are no longer required.

In 1954, Rossi founds Concast AG, short for “Continuous casting”, in Zürich, Switzerland. As early as 1956, Concast and Schloemann sign a cooperation agreement. In 1969, the Düsseldorf-based company assumes majority control of Concast. As a pioneer in this field, we have continued to offer the widest range of continuous casting technology solutions right up to the present day. This includes, for example, slabs with a thickness of between 50 and more than 500 millimeters and round billets 1,000 millimeters in diameter.

Irving Rossi, the "father" of continuous casting, and Heinrich Tanner, Managing Director of Concast in 1961.
Slab caster at August-Thyssen-Hütte (Germany) in 1969.
Billet caster at Röchling (Germany)
The bloom caster, Taewoong (South Korea) ...
... is designed for blooms up to 1,000 mm diameter.
Continuous caster for ultra-wide slabs at Shandong Iron & Steel Group Co. Ltd., Rizhao
Caster pulpit at Shandong Iron & Steel Group Co. Ltd., Rizhao

The seamless revolution

Even now, the seamless tube is inextricably linked to the name “Mannesmann”. 1885 is the year in which brothers Reinhard and Max Mannesmann present their solution that combines cross and pilger rolling, thus enabling the production of seamless tubes. Maschinenfabrik Meer delivers its first seamless tube rolling mill in 1923. From 1926 to 1999, “Meer”, as it is known, is part of the Mannesmann group and thus directly involved in advancing and perfecting the tube and pipe making process.

In 2003, SMS launches its PQF® technology (Premium Quality Finishing) on the market. It is designed to manufacture the highest quality products in an efficient and reliable manner, whether it’s high-alloy steel tubes or especially thin-walled precision tubes. As less material is used during production, yield is higher than with conventional solutions. Because only a slight amount of reheating takes place during the rolling process, PQF® also reduces the carbon footprint of seamless tube production.

Seamless tubes – produced on a Meer pierce-rolling mill, 1935.
Fully automated plug mill from Meer for the production of steel tubes from the 1950s.
Stretch-reducing mill.
Inaguration of first PQF® plant at TPCO
The first PQF® plant at Tianjin Pipe Corporation, China.
PQF® mill stand, exit side.
PQF® mill in Changbao’s Seamless tube plant.

Pulpit of PQF® plant Changbao

How the Bell-Less Top system transformed blast furnace technology

Among all the many innovations developed by Paul Wurth, the bell less top system (or BLT for short) is one that stands out. In the early 1970s, it provides the solution to one of the biggest problems of the steel industry, which, on the one hand, wanted bigger and more productive blast furnaces, while having to accept on the other hand that this was not possible with the traditional, superheavy furnace top. Many companies seek to address this issue, but it is the bright minds at Paul Wurth who ultimately come up with the ideal solution: the bell less top. With this revolutionary concept, the bell system is replaced by a rotating chute, which enables continuous charging and allows operators to position the charging material precisely in the blast furnace.

The first installation of the system in blast furnace number 4 at Thyssen in Duisburg-Hamborn in January 1972 impressed even the doubters and skeptics. The bell less top goes on to have a huge impact on the development of Paul Wurth and on the industry as a whole, as all over the world it enables the construction of larger blast furnaces with far higher productivity levels. The system is subsequently installed in over 800 blast furnaces across the globe. And today, with the BLTXpert, the Bell Less Top performance and condition monitoring system, this outstanding technology is part of the digital future of iron production.

The so-called "Spanish sketch". The initial concept of the bell-less top was developed by Edouard Legille during during a rainy stay in Spain.
For testing, Paul Wurth built a a prototype bell-less top at the own workshop.
Reduced-scale model of BLT.
On Sunday, January 9, 1972, the first bell-less top in the world started operation at August Thyssen Hütte's BF 4 in Duisburg, Germany.
The twin rotating and tilting movement of the chute enables the burden materials to be dumped exactly.
50 years after the installation of the first BLT at ThyssenKrupp Steel in Hamborn, we exchanged the gearbox.

Innovation is part of our DNA

The above examples show: It is in our company’s DNA to explore new technologies and to work closely with our customers to write history anew.

Yet there is not only one source of innovation. Alongside customers’ individual wants and needs, the big social, economic, and technical trends also inspire us, of course. Among the key drivers now are digitalization and green metals. That’s why our #turningmetalsgreen mission is also a logical consequence of the transformative phase the entire metals industry is currently going through in the fight against climate change. The fact that our customers will have to become greener and more sustainable is what motivates us to develop innovative technologies that push the boundaries of what is possible. That is because we are a key enabler of this transformation.

We innovate at many different levels. Our Research & Development unit plays a vital role in this. Interdisciplinary teams develop new plants, technologies, and processes and, to do this, utilize the latest tools and methods, such as structure analyses, fluid mechanics, dynamic simulations, or virtual and augmented reality. They also collaborate closely with university and non-university research institutions.

It goes without saying that there can be no innovation without investment: last year alone, more than EUR 129 million went into the field of research and development. The Innovation Hub we set up in 2023 is again taking our research work to the next level. The clear goal here is to bring innovations quickly to market maturity, in order to make decisive advances in the decarbonization of the metals industry.

There’s one other thing you need to drive innovation: courage. Back in 1985, the construction of a CSP® pilot plant represented a considerable financial risk. The same applies today. When the foundation stone for Mercedes-Benz’s battery recycling factory is laid in March 2023, it constitutes the first major order for our joint venture Primobius. The development of the technology would not be feasible without the tests on the pilot plant in Hilchenbach.

What are the next big innovations? We think it is EASyMelt. The electric-assisted syngas smelter is an alternative to direct reduction and is aimed at accelerating the decarbonization of existing integrated steel plants. In 2023, we signed a memorandum of understanding with Tata Steel to implement our innovative EASyMelt technology in a blast furnace in India. It is quite possible that the next revolutionary technology will emerge from Jamshedpur in India.

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