Cobalt is a rare heavy metal, which occurs mostly only in combination with other elements. It is usually extracted from copper and nickel ores. In the past, cobalt was mainly used to produce colour pigments. Today this element is used in batteries and as an alloying element, among other things.

Erythrite| Cobalt - Mineral

Steels alloyed with cobalt have an extremely high wear resistance and keep their strength even at high temperatures. For this reason, cobalt steels are ideal for components that have to withstand particularly heavy loads, such as engine and turbine components.

Der Einfluss von Kobalt auf die mechanischen Eigenschaften von Stahl:

Property Influence Degree
Rust resistance no bearing 0
Hardness Improvement + 1
Strength Improvement + 1
Yield strength Improvement + 1
Elasticity no bearing 0
Heat resistance Improvement + 2
Carbide formation no bearing 0
Wear resistance Improvement + 3
Nitratability no bearing 0
Strain Decrease - 1
Reduction of area Decrease - 1
Notched Impact Strength Decrease - 1
Forgeability Decrease - 1
Scaling Decrease - 1
Machinability no bearing 0


Cobalt ore was often wrongly identified as silver ore in the Middle Ages. However, cobalt ores usually also contain sulphur and arsenic compounds, which caused bad smells during smelting. The miners believed that cobolts had eaten the precious silver and left the cheap cobalt behind.

The chemist Georg Brandt discovered the metal in 1735 while experimenting with "kobold ore". Inspired by this medieval story, he named the metal cobalt.

See also

Accompanying Elements

Steel does not only consist of iron and carbon. Other elements can influence the properties of steel.

Read more
Alloying Elements

There is a large number of different alloying elements. Each one influences the material properties.

Read more

Here you can find out why aluminium was discovered so late and how aluminium can be produced.

Read more

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