Special steels are steels with specific characteristics that come from the different elements used for their composition and heat treatment to which they have been subjected.
Some examples of the elements that these steels can contain, in addition to carbon, are chrome, nickel, silicon, tungsten, vanadium, cobalt, manganese, etc.
The fundamental difference that makes a special steel stand out from another type, commonly used, is the voluntary addition of these elements to alter the basic characteristics of the material, seeking physical, technological and mechanical properties that are superior to those of common steel.
These consist of four main subgroups:
- non-alloy steel (with the exception of steels for high-speed mechanical processing), with average manganese content lower than 1%;;
- non-alloy steel with average manganese content lower than 1%; non-alloy steels for high-speed processing, low-alloy steels with the weight of each element accounting for less than 5%;
- high-alloy steels (if they have at least one alloy element over 5%);
- high-speed steels.
The use of these materials, known as special steel, has allowed fast development and large-scale innovation over the last few years in the fields of aviation and motoring, improving the production and the design of tools. They have been widely used in the sector concerning artillery and armour. Only lately have interesting applications been discovered for the large-scale building industry, such as the building of large structures or bridges.
According to the elements used to improve metal alloys, it is possible to introduce different characteristics, such as:
- improvement of mechanical properties;
- increased heat resistance;
- increased resistance to chemical agents;
- increased magnetic permeability;
- reduced dilation coefficient;
It is also important to take into account the fact that thanks to the increase in hysteresis during the transformation process, special steels may also be affected by hardening.
Sidertaglio manufactures 6 different types of Special Steel: