浸炭材の低サイクル衝撃疲労特性に及ぼす表層炭素濃度と硫黄含有量の影響

抄録

Effect of surface carbon and sulfur on the low cycle impact fatigue properties in carburized steels were studied by using gear impact testing machine and strain gauge. The results obtained are summarized as follows: The low cycle impact fatigue strength was especially improved by decreasing content of the surface carbon and content of sulfur. It was found that increasing the crack initiation life by decreasing content of the surface carbon, and the initial crack length shorten. Furthermore, It was explained that the crack propagation speed decreased with decreasing sulfide. The method for estimating the crack initiation life from tensile properties of carburized layer is proposed by modifying Manson's Universal Slope Method.