Experimental Study of the Effects of Surface Defects on Rolling Contact Fatigue Behavior

2007 ◽  
Vol 353-358 ◽  
pp. 254-257
Author(s):  
Guan Chen ◽  
Hong Ping Zhao ◽  
Shao Hua Ji ◽  
Xi Qiao Feng ◽  
Hui Ji Shi
Keyword(s):  
Failure Modes ◽  
Surface Defects ◽  
Fatigue Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Surface Cracks ◽  
Hardness Tester ◽  
Rolling Surface ◽  
Contact Fatigue Resistance

Rolling contact fatigue (RCF) cracks initiated from surface and subsurface defects are typical failure modes of bearing systems. In this paper, the effects of surface defects on RCF behavior of M50NiL and M50 steels were studied experimentally. Artificial dents were introduced on the rolling surface by using Rockwell hardness tester. The influences of dent shape and dent shoulders were examined by thrust-type RCF tests. Surface cracks initiation, propagation and spalling were monitored by scanning electron microscope (SEM) observation. The results showed that artificial dents reduce RCF lives of M50NiL and M50 steels with mineral oil lubrication. The fatigue failure initiates at the surface defect with the effects of dent shape and dent shoulder. M50NiL steel has higher contact fatigue resistance than M50. The features of surface and sub-surface cracks propagation during RCF tests were also observed.

The Microstructure Control and Rolling Contact Fatigue Behavior of a Hot Worked Automotive Application

Materials ◽  
2005 ◽  
Author(s):  
Jae-Seong Lee ◽  
Chan-Hyun Son ◽  
Bok-Han Song ◽  
Hyo-Seup Han
Keyword(s):  
Grain Size ◽  
Fatigue Resistance ◽  
Fatigue Behavior ◽  
Rolling Contact Fatigue ◽  
Hot Forging ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Automotive Application ◽  
Contact Fatigue Resistance ◽  
Ferrite Grain Size

Once hot forgings for automotive parts such as wheel bearing flange to which cyclic asymmetric bending stress is continuously applied are produced, their microstructure, such as ferrite, should be controlled appropriately for obtaining of superior mechanical properties. However, it is hard to control the microstructure uniformly because mechanical strength is reduced as coarsening of ferrite grains. To investigate the microstructural alteration based on process parameters during hot working, the variation of the ferrite grain size, hereafter FGS, was investigated by utilizing of the computer-controlled servo-hydraulic Gleeble tester which can reproduce hot deformation behavior. In addition, the effect of ferrite grain size of raw material on austenite grain behavior of hot forgings was also examined. The rolling contact fatigue resistance of induction-hardened SAE1055 steel was compared with the result of induction-hardened SAE52100 bearing steel. As a result, it was confirmed that ferrite grain sizes of hot forging depend on heating temperature and cooling-start temperature during hot forging and cooling operations. Induction-hardened SAE1055 steel showed superior rolling contact fatigue resistance to induction-hardened SAE52100 steel. This fact appears that SAE1055 steel is freer from material defects such as segregateion than comparative steel.

scholarly journals Rolling Wear of Silicon Nitride Bearing Materials

1990 ◽  
Author(s):  
John W. Lucek
Keyword(s):  
Fatigue Life ◽  
Silicon Nitride ◽  
Failure Modes ◽  
Fatigue Testing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Performance ◽  
Wear Rates ◽  
Bearing Materials

Rolling-contact fatigue test methods were used to measure the wear performance of several silicon nitride materials. Sintered, hot pressed and hot isostatically pressed materials exhibited wear rates ranging over three orders of magnitude. Hot isostatically pressed materials had the lowest wear rates. Despite the disparity in wear performance, all materials tested had useful rolling-contact fatigue lives compared to steel. Fatigue life estimates, failure modes, and rolling wear performance for theses ceramics are compared to M-50 steel. This work highlights the rapid contact stress reductions that occur due to conformal wear in rolling-contact fatigue testing. Candidate bearing materials with unacceptably high wear rates may exhibit useful fatigue lives. Rolling contact bearing materials must possess useful wear and fatigue resistance. Proper performance screening of candidate bearing materials must describe the failure mode, wear rate, and the fatigue life. Guidelines for fatigue testing methods are proposed.

A Coupled Multibody Finite Element Model for Investigating Effects of Surface Defects on Rolling Contact Fatigue

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Zamzam Golmohammadi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Surface Defects ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Internal Stresses ◽  
Fe Model ◽  
Elastic Plastic ◽  
Pile Up

A coupled multibody elastic–plastic finite element (FE) model was developed to investigate the effects of surface defects, such as dents on rolling contact fatigue (RCF). The coupled Voronoi FE model was used to determine the contact pressure acting over the surface defect, internal stresses, damage, etc. In order to determine the shape of a dent and material pile up during the over rolling process, a rigid indenter was pressed against an elastic plastic semi-infinite domain. Continuum damage mechanics (CDM) was used to account for material degradation during RCF. Using CDM, spall initiation and propagation in a line contact was modeled and investigated. A parametric study using the model was performed to examine the effects of dent sharpness, pile up ratio, and applied load on the spall formation and fatigue life. The spall patterns were found to be consistent with experimental observations from the open literature. Moreover, the results demonstrated that the dent shape and sharpness had a significant effect on pressure and thus fatigue life. Higher dent sharpness ratios significantly reduced the fatigue life.

Effect of ultrasonic surface rolling on microstructure and rolling contact fatigue behavior of 17Cr2Ni2MoVNb steel

2019 ◽  
Vol 366 ◽  
pp. 321-330 ◽  
Author(s):  
Ya-Long Zhang ◽  
Fu-Qiang Lai ◽  
Sheng-Guan Qu ◽  
Hai-Peng Liu ◽  
Dong-Sheng Jia ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact
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