Author(s)

S. Nishida, N. Hattori, W. Zhang & M. Koga

Abstract

The effect of pre-strain on fatigue properties has been investigated using h\o kinds of typical structural plain carbon steels (S15C and S45C). The specified prc-strain \as gi\en to the specimens by the Instron-type precise tensile testing machine, and the fatigue test specimens were cut out from the pre-strained specimens without working the testing portion Fatigue damage had been intermittently observed by the successive-taken replica method and fractographic analysis was applied to the broken specimens after fatigue test Though the only plastic slip lines are observed in the boundary area between ferritic grain and pearlite block by the static tensile strain of 5% without crack initiation in the case of §150. some cracks are observed in the pearlite block by the static tensile strain of r, p = 4.8%. The fatigue limit of S15C is somewhat lower at

Keywords