This data set contains the results of rotating-beam reversed-bending fatigue tests for a wide range of aluminum casting alloys. These fatigue curves are the results of tests on individual lots of material considered representative of the respective alloys and tempers.

This chapter deals with the effects of fatigue in rotating shafts subjected to elastic and plastic strains associated with bending stresses. It begins with a review of the basic approach to treating low-cycle fatigue in bending, explaining that the assumption that stress is proportional to strain is incorrect due to plastic flow, causing considerable discrepancy between measured and calculated stresses. Data plots of the axial and bending fatigue characteristics of a 4130 steel help illustrate the problem. A closed-form solution is then presented and used to analyze the effects of flexural bending on solid as well as hollow rectangular and round bars. The chapter also discusses the difference in the treatment of a rotating shaft in which all surface elements undergo the same stress and strain and a nonrotating shaft in which a few surface elements carry most of the load. The difference, as explained, is due to the volumetric effect of stress in fatigue.

This chapter discusses the various factors influencing the evaluation of fatigue fracture of nitrided layers. It begins by describing the problems of enhancing the fatigue resistance of machine components. The significance and detailed assessment of the effect of a structural flaw are then explained, using investigations of the effect of variable core conditions on fatigue resistance as an example. This is followed by a discussion on the processes involved in the evaluation of fatigue properties of nitrided steels. The chapter also describes the determination of the fatigue characteristics of nitrided steels after the carbonitriding treatment.