Precise and Sustainable: A Knife Made of Water Complements the Special Steel
September 09, 2026 | Reading time: 10 minutes
High-strength specialty steels necessitate a cutting process that does not alter their properties. Ilsenburger Grobblech GmbH is now relying on one of Europe’s largest waterjet cutting systems for this purpose – and is thereby reducing its CO₂ footprint.
The harder the steel, the more sensitive it is to cutting. More specifically, this refers to the heat generated when heavy steel sheets are cut by way of a flame or plasma. What sounds like a contradiction – a material that withstands extreme stresses yet cannot tolerate the very process of being cut – is a genuine problem in heavy plate production – and the reason for an investment in the future in Ilsenburg.
Ilsenburger Grobblech GmbH, a subsidiary of Salzgitter AG, manufactures sheets between 6 and 175 millimeters thick – for the energy sector, construction machinery, mining, and security applications, among others. For many of these grades, the key challenge enters the picture at the end of the process chain: Once the sheet has been rolled and heat-treated, it must be brought into its final shape. To do this, cutting processes straighten the edges, trim excess material at the head and tail ends, and cut out samples for quality testing. In conventional flame cutting, the flame heats the cut edge locally to several hundred degrees and severs the material. In the case of standard structural steels, this is not a critical issue.
Heat becomes a risk with premium heavy plate
With high-strength and wear-resistant steels – such as those used for excavator buckets or conveyors in mining – the rapid temperature change can alter the microstructure at the edge: While the steel becomes harder there, it loses its toughness and is prone to cracking. “We sometimes process sheets larger than 30 square meters that have exactly the same properties at every point. The cutting process must not compromise this quality,” explains Robert Kühn, CEO of Ilsenburger Grobblech GmbH. In order to avoid this, the company previously had to resort to a detour, namely preheating the plates in the furnace once again before cutting. This additional step consumes furnace capacity and energy, requires crane movements, and extends delivery times.
Cold cutting instead of hot pre-treatment
A new waterjet cutting system eliminates this detour and consists of a purely mechanical process. A waterjet, mixed with fine garnet sand and accelerated to three times the speed of sound, cuts through the steel. The result: no heat input, no altered properties at the edge, and no tendency to crack. The system is manufactured by H.G. Ridder Automatisierungs-GmbH in Hamm and ranks among the largest 4-head waterjet cutting systems the company has produced in Europe to date. The cutting table measures 18 meters in length, with a maximum cutting width of 5.7 meters. By comparison, the standard width of such systems is one and a half meters. Two high-pressure pumps generate a pressure of up to 3,800 bar. Four cutting heads make it possible to process two sheets of metal in parallel. “The production cycle is shortened, delivery times are reduced, and scheduling becomes more flexible,” says Kühn. Following extensive testing, the cutting system is now transitioning into regular production.
What is heavy plate?
Heavy plate refers to flat steel products with a thickness of approximately 6 millimeters or more that leave the rolling mill as flat sheets – often several meters wide and over ten meters long. They are deployed wherever heavy-duty, high-strength steel structures are required: in wind turbine towers, bridges, ships, construction machinery, or pressure vessels. Ilsenburger Grobblech GmbH specializes in manufacturing highly specialized grades: wear-resistant steels (BRINAR®, MAXIL®) for mining and construction machinery, as well as security steels (SECURE) for protective applications – and all these high-quality grades require special care during cutting.
Reduced CO₂ emissions on several levels
The facility supports the Salzgitter Group’s sustainability strategy. Natural gas is burned during oxy-fuel cutting – and also when preheating crack-prone sheets in the furnace. The waterjet process eliminates both of these processes. The high-pressure pumps are electrically powered. Ilsenburger Grobblech sources an increasing share of the electricity required for this from wind and solar farms. Closed-loop systems are also in place for water and sand: The water circulates in a closed-loop treatment system, and fresh water is added only in small quantities to compensate for evaporation losses. The used garnet sand is returned to the supplier, where it is recycled and reused for other purposes – such as sandblasting. In the long term, this results in a largely low-carbon cutting process.
The European heavy plate market is regarded as oversupplied. To what extent does the current investment help the company hold its own against the competition?
Historically, European heavy plate capacities were designed for mass-market segments such as shipbuilding or bridge construction and are simply too sizeable for today’s demand. Furthermore, when it comes to standard steels, it’s nearly impossible to win the price wars against low-cost countries. We’re taking a different approach: We are relying on metallurgical expertise and know-how, the most advanced, state-of-the-art heat treatment, and now a cutting process that preserves the material properties right down to the very edge. The waterjet cutting system completes a production chain that is centralized at the Ilsenburg site, ranging from alloy development to sheet metal ready for shipment. This requires less tonnage than a mass-production business, while involving significantly greater vertical integration – and this is where we hold a competitive advantage.
Waterjet cutting takes longer than thermal cutting. How does that fit with a company that processes 700,000 metric tons of steel per year?
When it comes to standard structural steels, flame and plasma cutting continue to work perfectly and are also used in our operations. The new system specifically serves the most complex segment of our production – a manageable share in terms of tonnage, but the most demanding in terms of quality. And as for speed: We deliberately designed the system with four cutting heads so that at least two sheets can be processed in parallel. Above all, however, the time and emission savings throughout the entire process are crucial factors. The preheating furnace is no longer required, crane movements are reduced, and throughput time is significantly cut short. We no longer burn any natural gas for waterjet cutting. The high-pressure pumps are electrically powered, and we are increasingly sourcing our electricity through power purchase agreements with wind farm and solar power operators.
Which of your customers are benefiting the most from the new installations?
Primarily customers who purchase our BRINAR® and MAXIL® wear-resistant steels, as well as our security steels Secure. These are precisely the grades where thermal cutting reaches its limits. In the future, these customers will receive sheet metal whose properties remain unchanged right up to the edge – and in connection with shorter delivery times. For us, the new facility represents a strategic step that brings together premium quality and green transformation – and in this respect, we are pioneers in the European heavy plate market.
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