Heat treatments can be applied on the entire bearing or on some of its parts most subject to particular stresses or impacts in order to minimize the risk of structural deformation. We mainly carry out two types of treatments:
Cementation or carburizing serves to increase the surface hardness of some types of steel, allowing better resistance to wear, corrosion and impact. This process consists in enriching the outer layer of mild steel (low carbon) by adding additional carbon in order to modify the molecular structure and therefore make it more resistant; the core, on the other hand, maintains the original structure, thus ensuring the original toughness of the alloy. Subsequently it is always necessary to reclaim, that is the process of hardening and tempering.
Hardening and tempering are carried out to treat various types of steel, including 100Cr6.
Hardening consists in bringing the material to a temperature between 750-800 ° C and then cooling it quickly by immersing it in a liquid. This treatment modifies the structure transforming it into martensite, a material with high hardness and considerable breaking load, but with a low impact resilience that can cause fractures, for this reason the subsequent tempering step is necessary.
Tempering takes place at about 220 ° and allows to obtain an optimal hardness / toughness ratio according to the product applications; this serves not to frustrate the hardening operation which gave the material high hardness but which, on the other hand, made it less resistant to impact.