How is steel obtained


The discovery as a material

Steel is an alloy, i.e. a mixed metal that is created by melting several substances together. Today there are more than 2500 standardized types of steel worldwide, all of them mainly made of pig iron.

Pig iron consists of the element iron and more than three percent carbon. The high carbon content makes pig iron brittle, so that it breaks easily. The pig iron is extracted from iron ore.

Nowadays this is done in blast furnaces. The pig iron obtained there is further processed into steel in the steelworks. Steel now only has a carbon content of less than two percent.

This makes the material softer so that it can now be forged and rolled easily. Steel is elastic, but stable and resistant and therefore a popular material. But it was a long way to today's steel production.

The history of steel begins more than 5000 years ago: At that time, however, the Egyptians processed iron-containing meteorite rock that at some point landed on earth from space. The first people to understand how to work iron into steel lived in the Middle East around 1400 BC.

In Europe, steel processing only begins with the beginning of the Iron Age. Around 800 BC, the Celts discovered the first large iron ore deposits in Upper Austria. They learn to harden the iron by heating it and from then on they make weapons, tools, but also jewelry and bowls from iron.

Steel becomes liquid

It will be a long time before iron can also be cast in this country. The temperatures that the Celts produce in the so-called racing ovens are only sufficient to obtain a doughy mass, the "lump". By hammering, they can drive the slag out of the hollow and process the material further.

Only the development of blast furnaces since the 14th century has made it possible to heat the iron to such an extent that it remains liquid.

The blast furnace of that time can only be compared to a limited extent with today's blast furnaces. In the 17th century, four tons of charcoal were needed to get one ton of pig iron, today less than half a ton of coking coal is needed to produce one ton of pig iron.

Steel is becoming a mass product

People discovered early on that steel can be used not only to make jewelry and pots, but also tools and weapons. In the mid-19th century, Henry Bessemer, in search of ever better, more resistant weapons, developed a new method that was to remain in use for a long time to come.

The Bessemer or Thomas process makes steel production easier by using compressed air. Until then, the workers had to stir the molten steel with great physical exertion in order to separate the unusable materials from the iron. Now a machine can do this.

The Siemens-Martin process, which enables scrap to be remelted into steel, also promotes steel production. In 1850, every blast furnace worker produced eight tons of pig iron a year; 20 years later it was ten times as much.

The faster and cheaper steel can be made, the more in demand it becomes. It is the age of industrialization. New inventions and technical developments are mutually beneficial. In order to transport the ever-increasing amounts of coal, iron and steel, you need railways and rails, which are becoming more and more stable thanks to advances in the iron and steel industry.

Steel is now also used for mass production. Whether trains, cars, ships, planes or tanks - the automotive industry would be inconceivable without steel.

Steel barons

At the beginning of the 19th century, Friedrich Krupp founded a cast steel factory in Essen. He is one of the first in Germany, because at that time steel mainly came from England. When his son Alfred Krupp took over the company in 1826, it had seven employees. When he died in 1887, he left a company with around 20,000 employees.

A milestone for the company is the construction of unbreakable, seamlessly forged wheels for railways. In the form of three intertwined rings, they become the Krupp logo.

In 1912, scientists at the Krupp company discovered by chance how rustproof steel could be manufactured. The so-called V2A or stainless steel is an alloy of iron, chromium and nickel. It is used, among other things, in medical technology and for kitchen appliances.

The family business continues to grow, only a few competitors can keep up. One of them is August Thyssen, who built his first steel factory in Mülheim an der Ruhr in 1870. At the beginning of the 20th century, the Thyssen works were even producing more steel than their biggest competitor Krupp.

But the Krupp company enjoyed the special trust of the imperial family and therefore became the main supplier of war material. A business that also brings the company high export income.

The power of the steel industry

The First World War turns into an industrial war, in which not only Krupp but all heavy industry is ultimately involved. More and more weapons are needed for war.

Not only politics, but also heavy industry is interested in the military conquests, because they need raw materials for their steel production. The largest iron ore deposits are in Lorraine. But industry also formulates territorial claims for Belgium, Poland, the Baltic States and even Africa.

Despite the defeat in World War I, in 1929 Germany again became by far the second largest steel producer in the world after the USA. Some of the steel companies are starting again with the development of armaments.

While Gustav Krupp von Bohlen und Halbach was initially aloof from the National Socialists, Fritz Thyssen joined the NSDAP as early as 1931 and supported Hitler's political program. Nevertheless, it is the Krupp company that becomes the "armory of the empire" during the Second World War. They come to terms with Hitler's policy and benefit considerably from the National Socialist armaments policy.

Fritz Thyssen, on the other hand, who still strongly supported Hitler in the 1930s, emigrated from Germany in 1939, disappointed by the violent National Socialist policies.

Between hope and fear

With the end of the Second World War, the steel industry initially appeared to be on the ground. But it was already blossoming again in the 1950s and became a symbol of Germany's economic reconstruction. But developments in the steel industry do not stand still.

Better and better processes mean that fewer workers can produce far larger quantities of better steel. The world economic crisis of 1973 finally brought the growth of steel production to a virtual standstill, from which it has not recovered to this day.

Numerous steel works are closing in the western industrial nations. The demand for steel is growing again in the Far East, but development is not standing still there either, and many countries are now producing steel themselves.

Nevertheless, the future does not look completely hopeless for the steel industry in Germany: Modern technology makes steel today a material that meets the requirements of the time. Recycling is at the forefront of the steel industry, because around 40 percent of today's crude steel consists of scrap.

While the large companies merge, many smaller steel companies, so-called "mini-mills", produce high-quality special steels. And, according to some experts, this is precisely where the future of the steel industry lies today.

Author: Sine Maier-Bode