Detailed Analysis of the Crack Behavior around the Surface Dent under Rolling Contact Fatigue

Author:

Fujioka Yuma1,Ishibashi Izumi1,Maeda Naoki1,Fujimatsu Takeshi1

Affiliation:

1. Material Research Group, Research and Development Center, Sanyo Special Steel Co., Ltd. 1 , 3007, Nakashima, Shikama-Ku, Himeji , Hyogo, 672-8677, JP

Abstract

With recent trends toward carbon neutrality, represented by the progress in the electrification of automobiles, there is an increasing demand for higher-efficiency power transmission parts. Given this background, lubricants have tended to decrease in viscosity. Therefore, it is expected that the low-viscosity state will be promoted by the rise in lubricant temperature during operation, thereby resulting in an increasingly harsher operating environment for bearings. For example, in electric vehicles, the rotation speed of the motor is increased by weight reduction and the greater efficiency of the drive units. Under such harsh environments, the working parts come into contact with one another and generate wear particles that can bring surface dents on the raceway. Furthermore, iron powder and scale may be accidentally brought to the surface of bearings for steel rolling mills, forming dents on the raceway. Surface dents are well known as a root cause of surface-originating premature flaking under rolling contact fatigue (RCF) in bearings. Previously reported results indicate that cracks are generated around the edge of the dent and then cause flaking because of crack propagation. Several previous studies proposed hypotheses on crack initiation mechanisms. However, there are few investigations of crack initiation mechanisms under a contaminated lubricating condition. In this study, the details of the crack generation process around dents were investigated so as to devise new countermeasures for further improvements in bearing steel materials. A rolling fatigue test was conducted in which hard steel particles were artificially introduced into the lubricant as foreign matter. Observation of the surface and cross sections of the specimen showed a causal relationship between the microscopic plastic deformation and crack initiation near the surface region around the dent. These findings are useful for developing countermeasures to strengthen steel against flaking that originates from a dent.

Publisher

ASTM International100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959

Reference18 articles.

1. Clarification of the Flaking Mechanism Caused by the Inclusion, Partially-Appeared on the Surface, under Rolling Contact Fatigue;Manabe;Sanyo Technical Report,2022

2. Mechanism of Dent Initiated Flaking and Bearing Life Enhancement Technology under Contaminated Lubrication Condition, Part I: Effect of Tangential Force on Dent Initiated Flaking;Ueda;Tribology International,2008

3. An Analytical Study of the Stress Concentration around a Furrow Shaped Surface Defect in Rolling Contact;Chiu;Journal of Lubrication Technology,1970

4. Effect of Dent on Rolling Fatigue Life;Toda;Tribologist,1993

5. Rolling Contact Fatigue Properties of Surface Hardened Steel under Contaminated Lubricant Environment;Hiraoka;Sanyo Technical Report,2002

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3