Chemical composition

[C] Carbon details max.
Carbon is the most important and influential alloying element in steel. The addition of additional alloying elements to achieve specific properties produces alloyed steel. As the carbon content increases, so too does the strength and the hardness of the steel, whereby its tensile strength, forgeability, weldability and workability are reduced.


[Cr] Chromium
Cr improves the hardness and thus the hardening and tempering characteristics of steel. It does, however, reduce the notch impact strength as well as ductility. Likewise, the more Cr in the steel, the worse its weldability. The tensile strength of the steel is increased by adding Cr. A Cr content of at least approximately 13% is required for the corrosion resistance of the steel.


[Ni] Nickel Details min.
In percentages of more than 7%, Ni added to a high Cr content produces chemically robust steels exhibiting an austenite structure until well below room temperature. Moreover, Ni in austenite Cr-Ni steels enhances resistance to the influence of reducing chemicals.  Cr-Ni steels are practically impossible to magnetise and are characterised by low heat and electrical conductivity.


[Mn] Manganese Details max.
Mn increases strength and wear resistance of steels.

[SI] Silicon
Details max. and [Al] Aluminium
Si and Al create ferrite; they increase the scaling resistance (scaling temperature) especially of ferrite steels (chromium steels with a relatively low carbon content).


[S] Sulphur Details max.
Although this tends to have a deleterious effect on steel, up to 0.4% S is deliberately added to machining steel. The lubricant effect on the tool cutting edge and as a consequence the reduced friction between workpiece and tool lengthen tool life. Moreover, machining steel produces shorter swarf during machining.


[Mo] Molybdenum
Along with other elements, Mo increases the hardenability of the steel. Mo also reduces the annealing brittleness of Cr-Ni steels and improves weldability. Mo is one of the elements that increases corrosion resistance and is therefore frequently added to highly alloyed Cr steels and Austenite Cr-Ni steels.

[
Ti] Titanium and [Nb] Niob
Ti has a highly deoxidising, denitrating effect, binds sulphur and forms carbide. So-called carbide formers are frequently found in corrosion resistant steels; Ti has a stabilising effect on inter-cyrstalline corrosion. [N] Nitrogen
N can both damage steel as well as be used as an alloying element. As an alloying element N stabilises the austenite structure especially and increases in austenite steels the strength, the yield strength as well as the mechanical properties when subject to heat. N can be used to achieve high surface hardness due to the formation of nitrates during nitrating.

[Ca] Calcium

Ca increases, even in small amounts and under certain smelting preconditions, the mechanical workability without negatively influencing the general performance properties.


[Cu] Copper
Even small concentrations (1.5%) of copper are capable of increasing the resistance to reducing acids (e.g. sulphuric acid).


[Mn] Manganese
Mn increases strength and wear resistance of the steels.