Surface hardening is a procedure that is usually performed on steel components, in order to impart in these the strength and surface hardness that are necessary for their correct operation, whilst maintaining a reasonable value of ductility in the overall component. The latter is usually composed of a sequence of heat treatments: carburizing, quenching and tempering. Each of these have different effects that, if correctly combined, can lead to the desired final mechanical properties in the component. Carburizing is a process that increases the amount of carbon concentration in the component surface. Quenching is a quick decrease in temperature that causes in the component different phase transformations and an increase in the surface hardness, causing however also a decrease in toughness.