In this work, a method to predict the fatigue limit by using Vickers hardness measurements is proposed.
Tests carried out in small regions of different annealed, quenched and quenched-tempered alloy steels
allowed an improvement of the empirical Murakami–Endo’s equation.
In this method, the plastic deformation caused by the indentation is assumed to be the defect from
which the process of initiation and propagation of cracks originate, analogously to small cracks.
Fatigue limits for four kinds of steels in different metallurgical states (annealed, quenched and
quenched-tempered) were estimated in two different ways, and the obtained values were compared
to the experimental ones. A good correlation between Vickers hardness and the fatigue limits estimated
by direct plastic deformation zone measurements using optical microscopy was envisaged.