The steel of the future: digital and climate-neutral

The production and application areas of steel are diverse and complex. In this article, our colleagues at thyssenkrupp Steel have given us a holistic impression of what the steel journey looks like and what they are already doing today to ensure that tomorrow's production can be completely climate-neutral.

Steel production: It all starts with iron ore

thyssenkrupp Steel produces its steel in highly automated process steps. Production begins with iron ore, which is used to produce a high-quality flat steel product at the end of the production chain. The iron ore is processed and used in the blast furnace in a so-called sinter plant. There, iron ore is baked into "sinter cakes" and broken into coarse pieces. At the same time, coking coal is baked into coke in the coke plant. The "baking" takes several hours. Today, coke is still an important reducing agent in blast furnaces. In the future, hydrogen will be used for pig iron production instead of coke.

30,000 tons of pig iron per day

The raw materials, sinter, coke and co. reach the 100m high blast furnaces at the next production station, where they are fed into the blast furnace from above. Hot air and coal dust are blown in from below. Inside the blast furnace, carbon and iron ore react in this way to form pig iron. In a process known as "tapping," the liquid pig iron produced is discharged from the blast furnace. This process is carried out on a large scale several times a day. On the thyssenkrupp Steel plant site in Duisburg, around 30,000 tons of pig iron are produced in this way every day. In CO₂ emissions, that is more than 55,000 tons of CO₂ per day. This makes the steel industry one of the biggest CO₂ emitters.

That's why our colleagues at thyssenkrupp Steel have set themselves the goal to produce climate-neutral by 2045. The first milestone is to produce three million tons of CO₂-neutral steel per year by 2030. Our colleagues want to achieve this transformation by using direct reduction. In this process, the use of hydrogen means that in the end only water vapor is emitted instead of climate-damaging emissions. The direct reduction process initially produces solid sponge iron. To liquefy this, it is heated in an innovative melting unit so that liquid pig iron is obtained at the end, which has the usual quality but was produced in a much more climate-neutral way.

From pig iron to high-quality flat steel product

The molten pig iron is then further processed into steel in the steel mill. This is done in the so-called converter by blowing in oxygen. This combustion process generates temperatures of over 1,700°C. Steel scrap is added as a coolant in this process. This is thus fully recycled and reprocessed into a high-quality product.

In secondary metallurgy, the steel is given its specific properties. It is achieved through certain alloying agents such as nickel, chromium, or manganese. This allows hardness, formability, toughness and corrosion protection to be defined. In the continuous caster, the steel is cast into shape and cut into so-called slabs.

Big Data in the hot and cold rolling mill

From the steel mill, the process continues to the hot strip mill. There the slabs are heated and rolled out using rolling stands. The result is a long steel strip that is wound into a coil. Up to this point, we have collected a great deal of data thanks to digital processes. Over 500,000 sensors, cameras, and microphones permanently monitor the processes. They are collected in the central cloud platform of our smelter: tera. All data is stored and managed there - from production and quality data to order and financial data to measurement and sensor data.

After the hot strip mill, our steel can be further processed if required. In cold rolling, the steel passes through rolling stands again, and the strip becomes thinner and longer. In the end, a cold-rolled coil can be over 5 kilometers long.

To protect the steel from corrosion, we can also finish it. In the electrolytic coating process, the steel strip is passed through an electrolysis bath, and in the hot-dip coating line through a zinc bath. Depending on requirements, the sheet can also be organically coated and colored lacquer applied. Barcodes along the entire length of the strip link information on the production location, production line and coil number as well as the quality of the material to the exact strip position. In this way, important information is supplied directly to our customers. This enables them to process and use the steel even more efficiently - a fully networked value chain. For example, our customers can already intervene directly in the production of their orders in our center strip mill in Hohenlimburg and determine for themselves when their steel is to be rolled with a lead time of 48 to 72 hours. In addition, they can adjust the material properties just a few hours before rolling. One-click ordering" is also possible.

At the customer's request, further processing in the cold rolling mill is possible. In cold rolling, the steel rolls are rolled out and can reach a length of 5 kilometers. In addition, corrosion protection is applied here. This finish is applied either by electrolytic coating in an electrolysis bath or by galvanizing in the hot-dip coating line. Organic coatings and colored paint can also be applied as required.  To enable us and our customers to track production steps and deliveries, all coils are equipped with barcodes. At our plant in Hohenlimburg, for example, our customers can intervene in processing. And adjust material properties with a lead time of around 48 hours. This digitalization of our production processes and delivery statuses creates trust, transparency, and flexibility.

Digitization and continuous optimization

Digitalization and continuous optimization along all process steps ensure greater efficiency and resource-saving production. For our colleagues at thyssenkrupp Steel, the real-time exchange of production data with our customers is important. We call this use of big data in steel production smart steel.

Without the help of digital solutions, it is also almost impossible to keep track of production on the huge plant site: Because the site in Duisburg is almost 5 times the size of Monaco. This makes the thyssenkrupp Steel plant in Duisburg one of the largest industrial sites in Germany. Raw materials reach the plant site by ship via the Duisburg plant harbor, and this can amount to as much as 60,000 tons of ore per day. The transshipment is supported by GPS and tracked with artificial intelligence. The evaluation of the geocoordinates enables the ships to be tracked precisely. Every day, 2,000 trucks and 100 locomotives pass through the plant gates. The track and trace system makes it possible to predict who will arrive where and when. In this way, our colleagues ensure the reliability of deliveries and create greater transparency along the entire process chain.

Steel - a material with transformation potential

The areas of application for steel from thyssenkrupp Steel are many and varied. Steel can be used as a packaging material, in the household, the energy industry, in mechanical and plant engineering and in the automotive industry. There the material is a driver of electromobility. Through lightweight body parts and their use in electric motors, steel holds great potential that is far from being exhausted. If you are interested in sustainable materials and green technologies, take a look at our sustainability stories.