EFFECT OF PRE-STRAIN ON FATIGUE PROPERITES IN LOW AND HIGH CARBON STEELS

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% pre￾strained 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.