抄録
In the present study, the effects of the tensile pre-strain ratio on the torsional fatigue properties have been investigated using three kinds of structural carbon steels, S15C, S25c and S45C in view-point of fatigue strength, crack initiation and propagation. According to the experimental results and observation of crack propagation properties, the main results obtained in this study are as follow : (1) For the non-aging processed specimen, when the pre-strain ratio is high, fatigue strength increases with the increase of pre-strain ratio. (2) Aging process improves the torsional fatigue strength of the structural carbon steels.
