In this work, Fatigue tests have been performed to investigate the
fatigue damage process for two kinds ofplain carbon steels, (low
and high carbon steels) . The effect of pre-strain process on fatigue
crack initiation and fatigue strength has been examined. The main
results obtained are summarized as follows: (1) In the case of low
carbon steel (0.15%C) , the fatigue limit of ~~'0% (non-pre-strained
specimen) is higher than or equal to those of ~,=2% and %=5% pre‌strained specimens and lower than that of &,=8% pre-strained
specimens. (2) In the case of high carbon steel (0.46%C), the
fatigue limit of ~~'0% (non-pre-strained specimen) is higher than
those of cp=2%, 5% and 8% pre-strained specimens . (3) Though
the fatigue limits of pre-strained specimens are lower than those of
non-pre-strained specimen , the fatigue limits increase according to
the increasing of pre-strain percentage for both of tested material.