Difference between iron and steel

Often iron and steel are lumped together. But the two metals are quite different in their properties. Especially in the field of forming iron and steel react differently. What differences between iron and steel actually exist and which one is really suitable for which purpose.

Iron or steel?

Iron is the pure metal iron. In contrast, steel is an alloy of metals, mainly iron. While, for example, cast iron can not be deformed after curing, steel can be further processed and shaped depending on the mixing ratio of the alloy.

Often the steel is defined by the carbon content in the alloy. For example, the carbon content in DIN EN 10020: 2000-07 is set at less than 2.06 percent. Only some types of chromium steels may contain a higher percentage of carbon.

Production of iron

Cast iron is liquefied in the blast furnace. In this case, the oxygen is removed by carbon. A by-product is slag that needs to be drained off. This liquid iron has a high carbon content, which is about 4.7 percent. The pig iron, however, can not be formed because it is very brittle due to the high carbon content. In cast iron, for example, this leads to various problems with cutting and welding.

Freshen - add oxygen

The inflation of the pig iron with oxygen is also called fresh. This will deform the later steel. In this measure, the carbon is burned in the iron and the value drops to the above-mentioned value.

Steel is not the same as steel

More than 2,500 types of steel are currently registered in the European Steel Register. This is due to the different alloys and their mixing ratios. In part, the nature of the steel but also depends on the further processing. So rolling and forging on the texture has a big impact.

  • over 2,500 varieties in the European steel register
  • Production 1.6 billion tons of steel per year worldwide
  • Steel most commonly used metal material
  • Steel has been known for 3,500 years

Modern steel

With the simple steel used by the Hethiters for weapons 3,500 years ago, modern steel, apart from the iron in the alloy, has little in common with the oxygen content alone. In the meantime, specific qualities have been incorporated into the respective steel grade, so to speak. For this purpose, other metals are mixed into the alloy and often also changed the manufacturing process.

  • deformability
  • welding tendency
  • corrosion behavior
  • strength

Tips & Tricks

Some types of steel are already commercially available as described above with improved corrosion performance. However, if you want to use steel or cast iron in the garden area, you should additionally protect it from rust in any case. Even if you want a rusty surface, this process must be interrupted at some point, so that the workpiece or the beautiful garden bench does not dissolve completely in rust.

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