Microscopic observation of shear-mode fatigue crack growth behavior under the condition of continuous hydrogen-charging

6th International Conference on Fracture Fatigue and Wear

Akaki, Y.^1 ; Matsuo, T.^2,3 ; Nishimura, Y.^4 ; Miyakawa, S.^4 ; Endo, M.^2,3

Graduate School of Engineering, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka

814-0180, Japan^1

Development of Mechanical Engineering, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka

814-0180, Japan^2

Institute of Materials Science and Technology, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka

814-0180, Japan^3

Materials Engineering RandD Division, DENSO CORPORATION, 1-1 Syowa-cho, Aichi, Kariya

448-8661, Japan^4

关键词: Cyclic shear stress;    Fatigue crack growth behavior;    High cycle fatigue;    Mechanical systems;    Mechanical transmission devices;    Microscopic observations;    Rolling contact fatigue;    Torsional fatigue;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/843/1/012051/pdf
DOI  :  10.1088/1742-6596/843/1/012051

来源: IOP

【 摘 要 】

Rolling bearings facilitate the smooth motion of moving mechanical transmission devices substantially reducing the energy loss. However, flaking failure caused in bearings by rolling contact fatigue can crucially deteriorate the integrity of an overall mechanical system composed using bearings. It is understood nowadays that this phenomenon is intimately associated with shear-mode (Mode II and III) fatigue crack growth caused by cyclic shear stress in the presence of large compression. Further, a problem has become of importance that the premature flaking in ball bearings could be caused by the assistance of the penetration of hydrogen into material during the operation. In this study, torsional fatigue test of a bearing steel (JIS SUJ2) was performed by using a newly-developed method of continuous hydrogen-charging. Based on the microscopic observation, it was found that continuous hydrogen-charging had an influence on the shear-mode fatigue crack growth behavior in the high-cycle fatigue regime and reduced the threshold level.