Manganese in steel and alloys
To date, such an element as manganese in steel and in alloys is used very widely, we can even say that it is a metal that is constantly used in the production of steel. And although the ore, which was called manganese, has been used by man since the 13th century, but this metal was discovered only in 1774. This discovery was made by the Swedish scientist K.-V. Scheele. But before the industrial application of manganese it was necessary to wait another hundred years.
In 1856, the English metallurgist R. Mushet received a patent for the following idea: when melting steel as a deoxidizer, use manganese. Indeed, when manganese is added to the molten steel, oxides of the ferrous are reduced, oxygen is removed, and the formation of sulfides of the feroue is prevented. The resulting manganese oxides and sulphides are easily separated from the metal and form a slag. And for deoxidation it is enough to introduce about 6 kg of manganese per ton of steel. The idea was so successful that it is still used today in metallurgy.
But it turned out that manganese is also good as an alloying additive to steel. In 1882 another English metallurgist R.-A. Hadfield suggested using steel for making railroad rails, in which there were 12-14% manganese. Steel with such an additive was characterized by high impact strength and wear resistance. It is believed that this steel is the first alloy steel. Among the other positive effects with the introduction of manganese steel found later, there is an improvement in weldability, hardenability, cutting and pressure.
Particular attention should be paid to steel grade G13 ("Hadfield's steel", containing 1,2% of carbon and 13% of manganese). It is used for the manufacture of parts subject to heavy wear and tear - tracks of tracked vehicles, buckets of excavators, arrows of railways, ball mills, crushers, etc. The high wear resistance of such a steel is explained by the fact that, under the action of high impact loads, the austenite of the surface layer becomes martensite. Technologically, after hardening, for example, working elements of the excavator bucket, G13 steel gets an austenitic structure, the hardness and wear resistance of which are not large. However, as soon as the bucket is put into operation and begins to work hard, crashing into the ground, the austenite, after being hit, turns into martensite in the surface layer. It turns out a remarkable set of properties - high hardness and wear resistance of the surface and high toughness of the core. They say - the steel is riveted. It is interesting that when a surface wears off, the transformation of austenite into martensite continues and advances into the interior of the part all the time in the process of work. The disadvantage of steel G13 - it can hardly be machined.
Another interesting alloy based on manganese is the "dumb alloy". It is an alloy containing 70% of manganese and 30% of kuprum. He does not make a sound when struck on it.
As an alloying element, manganese is also used in bronze and brass. As in steels, it increases strength and elasticity. For example, you need a spring, which must go current. Clean koprum for this is not suitable - elastic properties are low. But if we add 5% of manganese to the kupruma, we get a good current-carrying spring bronze.
Or here such alloy - 86,8% of silver, 8,8% of manganese, 4,4% of aluminum. It is used to make permanent magnets. How so? - you are surprised. Indeed, all three elements have nothing to do with ferromagnets. However, in the composition of the alloy, the resulting crystal lattice has ferromagnetic properties.
Manganese compounds are widely used in various technologies - both as colorants and as an oxidant in organic compounds, in the production of glass, in the ceramic industry. And how many applications in everyday life has the ordinary "potassium permanganate" potassium permanganate!
After all the above, it is not surprising that manganese is among the most used metals, and its world production is estimated at millions of tons.
