Rolling Bearing Life Modifying Factors for Film Thickness, Surface Roughness, and Friction

1981 ◽  
Vol 103 (4) ◽  
pp. 509-516 ◽  
Author(s):  
T. E. Tallian
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Film Thickness ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Practical Calculation ◽  
Modifying Factors

This paper facilitates practical calculation of rolling contact fatigue life, allowing for material, lubrication, and surface topography effects. Modifying factors for the predicted fatigue life are given for: material matrix strength; material defect severity; EHD film thickness/surface roughness ratio Λ; surface asperity slope σθ and boundary lubricated traction coefficient μa. Readily evaluated formulas are provided for the above factors. Calculated results show predicted life versus Λ with σθ and μa as parameters. Comparison with experimental data shows that the model covers most documented test results of life versus Λ. Scanty experimental data covering σθ and traction effects on life are compatible with the model predictions.

scholarly journals Rolling Contact Fatigue Life of Case−Hardened Steel Treated by Shot Peenings with Shot Diameters of 0.05 mm and 0.30 mm

2011 ◽  
Vol 86 ◽  
pp. 645-648 ◽  
Author(s):  
Lei Wang ◽  
Guang Liang Liu ◽  
Masanori Seki ◽  
Masahiro Fujii ◽  
Qian Li
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Shot Peening ◽  
Fine Particle ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Surface Hardness ◽  
Hardened Steel ◽  
Rolling Contact ◽  
Contact Fatigue Life

In order to investigate the influence of different shot peenings on the rolling contact fatigue life of case−hardened steel, the thrust type rolling contact fatigue test was performed with a ball−on−disk contact tester. In this study, the case−hardened steel disks were treated by the fine particle peening with a shot diameter of 0.05 mm and the normal shot peening with a shot diameter of 0.30 mm. The surface hardness and the surface compressive residual stress of the test disks were increased by these peenings. On the other hand, the surface roughness of the test disks was increased by the normal shot peening, and was decreased by the fine particle peening. The rolling contact fatigue test showed that the rolling contact fatigue life of the test disks was improved by the fine particle peening, and was not improved by the normal shot peening. The rolling contact fatigue life of the test disks became longer as their surface roughness became smaller. Therefore, it follows from this that the fine particle peening, which can provide the increase in surface hardness and the decrease in surface roughness, is good for the increase in the rolling contact fatigue life of case−hardened steel.

Rolling bearing seizure and sliding effects on fatigue life

2018 ◽  
Vol 233 (2) ◽  
pp. 339-354 ◽  
Author(s):  
Guillermo E Morales-Espejel ◽  
Antonio Gabelli
Keyword(s):  
Fatigue Life ◽  
Numerical Models ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Damage Mechanism ◽  
Rolling Bearing ◽  
Rolling Contact ◽  
Frictional Stress ◽  
Lubricated Contacts ◽  
Contact Fatigue Life

The effects of kinematic sliding on rolling contact fatigue life have been discussed in many occasions, often with some disregard of the fundamental principles of tribology. In this paper, the authors’ intention is to discuss this issue with a perspective as objective as possible and performing a study on factual and known scientific knowledge, applying tribology modelling and methods. The effects of kinematic sliding of Hertzian contacts are studied from three different standpoints: (1) by analysing the combination of sliding speed and contact pressure giving rise to seizure, that is high instantaneous contact temperatures leading to film collapse, (2) by assessing the possible effects of sliding to surface traction and fatigue, (3) by discussing other possible effects of sliding in heavily loaded lubricated contacts as the concurrent damage mechanism caused by wear and rolling contact fatigue. Throughout the paper, different numerical models are presented and discussed alongside with some experimental data. This approach provides a comprehensive assessment of the various phenomena related to the kinematic sliding of rolling bearings. The different mechanisms involved and the interaction of sliding with the elastohydrodynamic lubricant film, frictional stress, wear and fatigue are discussed, and their significance to the performance of the bearing is qualified.

A Parametric Investigation of Surface Initiated Rolling Contact Fatigue Using the Asperity Point Load Mechanism

2013 ◽  
Vol 577-578 ◽  
pp. 45-48
Author(s):  
Dave Hannes ◽  
B. Alfredsson
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Surface Stress ◽  
Crack Path ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Local Stress ◽  
Point Load ◽  
Rolling Contact ◽  
Residual Surface Stress

Rolling contact fatigue (RCF) will eventually become an issue for machine elementsthat are repeatedly over-rolled with high contact loads and small relative sliding motion. Thedamage consists of cracks and craters in the contact surfaces. Asperities on the contact surfacesact as local stress raisers and provide tensile surface stresses which can explain both initiationand propagation of surface initiated RCF damage. A parametric study was performed to inves-tigate the contribution of surface roughness, friction and a residual surface stress to the RCFdamage process. The effects on initiation, crack path and fatigue life at both early and devel-oped damage were examined for a gear application. Both a one-parameter-at-a-time approachand a 2-level full factorial design were carried out. Surface roughness and local friction prop-erties were found to control crack initiation, whereas the simulated crack path was primarilyaffected by the residual surface stress, especially for developed damage. Reduced surface rough-ness, improved lubrication and a compressive residual surface stress all contributed to increasethe simulated fatigue life. The asperity point load model could predict effects on RCF that areobserved with experiments. The results further support the asperity point load mechanism asthe source behind surface initiated RCF.

Rolling Contact Fatigue Type Analysis of Rolling Bearing by XRD and TEM

2012 ◽  
Vol 706-709 ◽  
pp. 1679-1684 ◽  
Author(s):  
H. Hidaka ◽  
Kouji Ueda ◽  
N. Mitamura
Keyword(s):  
Film Thickness ◽  
Fatigue Test ◽  
Retained Austenite ◽  
Ball Bearing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Bearing ◽  
Microstructural Change ◽  
Rolling Contact ◽  
Lubrication Condition

In the rolling bearing, the flaking caused by rolling contact fatigue is classified into two types: surface originated flaking and subsurface originated flaking. It has been recognized that marked microstructural change can occur in subsurface originated flaking due to rolling contact fatigue. But there are few reports in surface originated flaking about microstructural change. In this study, surface originated flaking caused by rolling contact fatigue was investigated based on microstructural change. Thrust ball bearing and radial ball bearing was used for fatigue test. Simulation of dent originated flaking was carried out using the bearing with artificial dent. Another fatigue test subjected to surface originated flaking was done under shortage of oil film thickness lubrication condition. Microstructural change was measured by X-ray Diffractmetry (XRD) and Transmission Electron Microscopy (TEM) during fatigue testing. Microstructure of bearing steel used for fatigue test is consisted of martensite with small amount of retained austenite. XRD measurement reveals that the half peak width of martensite and volume fraction of retained austenite decreasing with increasing testing time, and the amount of decrease in these parameter were small in the surface originated flaking compared with subsurface originated flaking when the specimens were flaking. This suggests that surface originated flaking occurs in spite of mild microstructural change. TEM observation about the surface originated flaking shows plastic flow in the surface layer. Especially, it was confirmed that partial recrystallization occurs in the fatigue test under shortage of oil film thickness lubrication condition. But it was also confirmed that degree of recrystallization is lower in the surface originated flaking than subsurface one, and this reasonably explains XRD result. From these results, it was cleared that recrystallizaiton of martensite is differ in degree but not in kind between surface originated flaking and subsurface originated flaking.

Influence of Surface Roughness Skewness on Rolling Contact Fatigue Life

1992 ◽  
Vol 35 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Yoshinobu Akamatsu ◽  
Noriyuki Tsushima ◽  
Toshihide Goto ◽  
Kenji Hibi
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Contact Fatigue Life

Rolling Contact Fatigue Life of AISI M-50 as a Function of Specific Film Thickness Ratio Using a High Speed RC Rig

1980 ◽  
Vol 102 (4) ◽  
pp. 534-538 ◽  
Author(s):  
A. H. Nahm ◽  
E. N. Bamberger
Keyword(s):  
Fatigue Life ◽  
Film Thickness ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Speed ◽  
Thickness Ratio ◽  
Rolling Contact ◽  
Contact Fatigue Life ◽  
Speed Regime

Rolling contact fatigue (RCF) life of AISI M-50 was investigated as a function of specific film thickness ratio by varying the rolling speed. RCD lives of M-50 were determined using two synthetic lubricants at rolling speeds of 2.5 m/s (98 in/s), 5.0 m/s (196 in/s), 12.5 m/s (491 in/s), and 25 m/s (982 in/s). These correspond to estimated specific film thickness ratios (Λ) of 0.45, 0.75, 1.48, 2.48 and 3.52, respectively. It was found that the RCF life increases substantially in both the mixed and full film lubrication regime while in the boundary regime, the fatigue life is relatively independent of the rolling speed. Results are discussed in terms of the lubrication life factor which is an important parameter in bearing design. It is suggested that the current ASME design guide lubrication factors are conservative, especially in the high speed regime.

Effect of Grain Flow Orientation on Rolling Contact Fatigue Life of AISI M-50

1982 ◽  
Vol 104 (3) ◽  
pp. 330-334 ◽  
Author(s):  
A. H. Nahm
Keyword(s):  
Fatigue Life ◽  
Flow Line ◽  
Flow Direction ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Vacuum Arc ◽  
Type I ◽  
Grain Flow ◽  
Contact Fatigue Life

Accelerated rolling contact fatigue tests were conducted to study the effect of grain flow orientation on the rolling contact fatigue life of vacuum induction melted and vacuum arc remelted (VIM-VAR) AISI M-50. Cylindrical test bars were prepared from a billet with 0, 45, and 90 deg orientations relative to billet forging flow direction. Tests were run at a Hertzian stress of 4,826 MPa with a rolling speed of 12,500 rpm at room temperature, and lubricated with Type I (MIL-L-7808G) oil. It was observed that rolling contact fatigue life increased when grain flow line direction became more parallel to the rolling contact surface.

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.

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