Manganese
Manganese was already discovered in 1774 by the chemists Scheele and Gahn. It is an important alloy component in steel production. It extracts the steel parasites sulphur and oxygen from the steel, has a hardening effect, and also improves the formability.
Manganese forms very strong compounds with oxygen. In the steel structure the harmful oxygen is bonded. Manganese also has a desulphurising effect. This prevents the formation of sulphides. Manganese stimulates the formation of austenite, because it increases the solubility of nitrogen. These properties are of great importance for many stainless steel grades.
The influence of manganese on the mechanical properties of steel:
| Property | Influence (1) | Degree (1) | Influence (2) | Degree (2) |
|---|---|---|---|---|
| Rust resistance | no bearing | 0 | no bearing | 0 |
| Hardness | Improvement | + 1 | Decrease | - 3 |
| Strength | Improvement | + 1 | Improvement | + 1 |
| Yield strength | Improvement | + 1 | Decrease | - 1 |
| Elasticity | Improvement | + 1 | no bearing | 0 |
| Heat resistance | no bearing | 0 | no bearing | 0 |
| Carbide formation | no bearing | 0 | no bearing | 0 |
| Wear resistance | Decrease | - 2 | no bearing | 0 |
| Nitratability | no bearing | 0 | no bearing | 0 |
| Strain | no bearing | 0 | Improvement | + 3 |
| Reduction of area | no bearing | 0 | no bearing | 0 |
| Notched Impact Strength | no bearing | 0 | no bearing | 0 |
| Forgeability | Improvement | + 1 | Decrease | - 3 |
| Scaling | no bearing | 0 | Decrease | - 2 |
| Machinability | Decrease | - 1 | Decrease | - 3 |
| (1) for pearlitic steels | ||||
| (2) for austenitic steels |
Trivia
The English research vessel "Challenger" explored the Pacific in 1873. In trawl nets the researchers found many potato-shaped stones, which were manganese. Shark teeth were found when breaking up these tubers. Calculations showed that in about 1000 years a layer of only 1.5 mm is formed. So these sharks died over 1.5 million years ago.
See also
Aluminium
Aluminium can be formed and machined extremely well. It is particularly suitable for lightweight constructions.
Read moreBauxite
Here you can find out why aluminium was discovered so late and how aluminium can be produced.
Read moreCarbon
The carbon concentration influences the hardness of steels. In this way, the right steel can be found for every application.
Read more