Download Free Subsurface Fatigue Crack Initiation And Propagation Behavior Of Induction Hardened Shafts Under The Effect Of Residual And Applied Bending Stresses Book in PDF and EPUB Free Download. You can read online Subsurface Fatigue Crack Initiation And Propagation Behavior Of Induction Hardened Shafts Under The Effect Of Residual And Applied Bending Stresses and write the review.

The Society of Automotive Engineers Fatigue Design and Evaluation (SAEFDE) Committee has been conducting a long-term program aimed at the development of a predictive capability for fatigue life of SAE 1045 induction-hardened shafts. As a part of a larger-scale investigation provided by the SAEFDE committee, this research provided an analytical model capable of predicting the total fatigue life, both crack initiation and crack propagation, of an induction-hardened shaft under applied bending stress. The analysis procedure incorporated the effects of residual stresses. Total stress intensity factors were calculated and superimposed using applied bending stress intensity factors and residual stress intensity factors along the subsurface elliptical crack front. Fatigue tests were conducted using SAE 1045 induction-hardened shafts to verify the analytical models of subsurface fatigue crack growth. The total fatigue life calculations of subsurface failure showed a factor from 0.6 to 0.8 compared with the experimental results. The analytical model and experimental data confirmed that the majority of the total fatigue life is spent in the crack propagation phase.
What is heat treatment? This book describes heat treating technology in clear, concise, and nontheoretical language. It is an excellent introduction and guide for design and manufacturing engineers, technicians, students, and others who need to understand why heat treatment is specified and how different processes are used to obtain desired properties. The new Second Edition has been extensively updated and revised by Jon. L. Dossett, who has more than forty years of experience in theat treating operations and management. The update adds important information about new processes and process control techniques that have been developed or refined in recent years. Helpfull appendices have been added on decarburization of steels, boost/diffues cycles for carburizing, and process verification.
The overload and/or underload occurring during constant-amplitude fatiguecrack growth result in the retardation and/or acceleration in the crack-growth rate, making it difficult to predict the crack-propagation behavior and fatigue lifetime. Although there have been numerous investigations to account for these transient crackgrowth behavior, the phenomena are still not completely understood. Neutron and X-ray diffraction, and electric-potential measurements were employed to investigate these transient crack-growth micromechanisms; gain a thorough understanding of the crack-tip deformation and fracture behaviors under applied loads; and establish a quantitative relationship between the crack-tip-driving force and crack-growth behavior. Five different fatigue-crack-growth experiments (i.e., fatigued, tensile overloaded, compressive underloaded, tensile overloaded-compressive underloaded, and compressive underloaded-tensile overloaded) were performed to observe these transient crack-growth behaviors. The development of internal-strain distributions during variable-amplitude loadings, and the resultant residual-stress distributions around a crack tip were examined using neutron diffraction. The effects of a single tensile overload on fatigue-crack growth were focused on probing the crack-growth-retardation micromechanisms. Neutron diffraction and polychromatic X-ray microdiffraction showed high dislocation densities and considerable crystallographic tilts near the crack tip immediately after the overload. The interactions between the overload-induced plastic zone and newly-developed fatigue-plastic zone, and their influences on the evolution of residual-strain profiles are discussed. Neutron-diffraction and electric-potential measurements provide in-situ observation of the crack-opening/closing processes and internal-stress distributions in the vicinity of the crack tip during real-time fatigue-crack propagation following a tensile overload. Immediately after applying a tensile overload, the crack-tip became blunt and the large compressive residual stresses were developed around the crack tip. In the retardation period after the tensile overloading, the combined effects of the cracktip blunting at an overload point and compressive-residual stresses accompanying the crack closure induced the stress concentration at a blunting region until a maximum crack-arrest load was reached. Then, the stress concentration was transferred from the blunting region to actual crack-tip position with gradual crack opening, requiring a higher applied load. This observation of the stress-transfer phenomenon significantly promotes the fundamental understanding of overload-retardation phenomena. The postoverload crack-growth rates were normalized with the effective-stress-intensity-factor range, which suggests that it can be considered as the fatigue-crack-tip-driving force.