As result, the presence of niobium increases the content of
vanadium in the solid solution after austenitizing, and consequently a higher secondary hardness is obtained. In steels containing a mass fraction of more than approximately 2 % Nb, coarse NbC+γ quasi-eutectic regions are formed. These regions are very stable and do not change during hightemperature heat treatment. The presence of these regions in the microstructure is deleterious because they affect the brittleness of the steel, but by using a powder metallurgy process they can be prevented. In order to achieve an alloy with maximum hardness it is necessary to find the optimum heat treatment for the steel [2,3,4,5].