0
TECHNICAL PAPERS

Detrimental Effects of Debris Dents on Rolling Contact Fatigue

[+] Author and Article Information
D. Nélias, F. Ville

European Institution of Tribology, Laboratoire de Mécanique des Contacts, CNRS UMR 5514, INSA de Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex, France

J. Tribol 122(1), 55-64 (Jun 01, 1999) (10 pages) doi:10.1115/1.555329 History: Received January 06, 1999; Revised June 01, 1999
Copyright © 2000 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fragmentation or deformation of particles for various nature of contaminant. (a) Brittle particles (SAE AFTD); (b) ceramic particles (B4C,SiC)); (c) ductile particles (M50).
Grahic Jump Location
Indentation features for tough ceramic particles depending on the rolling speed (a, b) and the location inside or outside the EHL contact (c) (contaminant concentration: 10 mg/l, initial particle size: 45 μm, test duration: 5 min, Hertzian pressure: 1.5 GPa, pure rolling, disks material: AISI 52100). (a) Boron carbide (B4C) at a mean rolling speed of 20 m/s; (b) boron carbide (B4C) at a mean rolling speed of 2.51 m/s; (c) silicon carbide (SiC) at a mean rolling speed of 20 m/s.
Grahic Jump Location
Profile of the dent. (a) Definition of the dent geometry; (b) comparison between mathematical and real dents.
Grahic Jump Location
Formation of micro-spalls ahead of the dent along the sliding direction on the surface of a disk made of AISI 52100 steel, after 60 106 cycles at 3.5 GPa, a rolling speed of 40 m/s, and a slide-to-roll ratio of +1.5%.
Grahic Jump Location
Preferred site of dent originated deep spalling. (a) Pure rolling; (b) negative sliding, i.e., the dent is on the faster surface; (c) positive sliding, i.e., the dent is on the slower surface.
Grahic Jump Location
Comparison between the result of numerical simulations and tests for two opposite slide-to-roll ratios. The upper row shows the pressure distribution and film thickness. The middle row gives a zoom view of the maximum shear stress isovalues in the vicinity of the dent (represented by a thick line). Both correspond to the maximum stress found while the dent is travelling through the EHL contact. The lower row shows dent micrographs after 200×106 cycles at 3 GPa and a rolling speed of 40 m/s. (a) Slide-to-roll ratio of +1.5%; (b) slide-to-roll ratio of −1.5%.
Grahic Jump Location
Location and values of the maximum shear stress when the dent is travelling through the contact and for two opposite slide-to-roll ratios. The upper row recalls the dent geometry. The middle row shows the location of the point (relatively to the surface) where the stress is found maximum. The lower row indicates the corresponding magnitude of the maximum shear stress.
Grahic Jump Location
Definition of three lubrication regimes corresponding to three typical sizes of dents. (a) Quasi-smooth EHL regime (the initial dent is totally absorbed by the elastic deformation of the surface); (b) μ-EHL regime without cavitation; (c) μ-EHL regime with cavitation.
Grahic Jump Location
Induced dent (situation where U2<U1) at 3 different time steps (from left to right)
Grahic Jump Location
Profile of two different types of dent studied, with and without shoulder
Grahic Jump Location
Comparison of pressure distribution and subsequent elastic stress field obtained with dry, stationary EHL, and transient EHL models for dents with (left) and without (right) shoulder. The upper row shows the pressure distribution and film thickness. The lower row gives a zoom view of the maximum shear stress isovalues in the vicinity of the dent. Both correspond to the maximum stress found while the dent is travelling through the EHL contact. (Hertzian pressure of 1.5 GPa and mean rolling speed of 40 m/s). (a) Dry contact model; (b) stationary EHL model (U1=80 m/s,U2=0 m/s); (c) transient EHL model, pure rolling (U1=U2=40 m/s); (d) transient EHL model, slide-to-roll ratio of +3% (U1=41.2 m/s,U2=38.8 m/s); (e) transient EHL model, slide-to-roll ratio of −3% (U1=38.8 m/s,U2=41.2 m/s).
Grahic Jump Location
Maximal local shear stress calculated in the vicinity of the dent (with shoulder) for different slide-to-roll ratios when the dent travels through the contact. (Hertzian pressure of 1.5 GPa and mean rolling speed of 40 m/s.)
Grahic Jump Location
Maximal local shear stress calculated in the vicinity of the dent (with shoulder) vs. slide-to-roll ratio. (Hertzian pressure of 1.5 GPa and mean rolling speed of 40 m/s.)
Grahic Jump Location
Location of the maximal local shear stress for two different slide-to-roll ratios
Grahic Jump Location
Lower bound of endurance limit H1 vs. slide-to-roll ratio calculated from the maximal local shear stress found in the vicinity of the dent. Dent with shoulder (depth: 1.5 μm, width: 40 μm, shoulder height: 0.5 μm). Shear elastic limit used in the calculation: 735 MPa (for M50 steel at 100°C). The limit H1 is also indicated for smooth surfaces, calculated from the maximal local shear stress found at the Hertzian depth with an alumina inclusion (factor of stress concentration=1.38) or without inclusion.
Grahic Jump Location
Shape of the deformed particle and of the related dent for M50 particles (particle size distribution: 32–40 μm, Hertzian pressure: 1.5 GPa, pure rolling, mean rolling speed: 20 m/s, disks material: AISI 52100). (a) Deformed particle; (b) dent with a hole at the center.
Grahic Jump Location
View of various contaminant. (a) Steel powder (M50); size distribution: 0–100 μm; specific mass: 7800 kg/m3 ; (b) Arizona Fine Test Dust (SAE AFTD); size distribution: 0–100 μm; specific mass: 2650 kg/m3 ; (c) Boron Carbide (B4C); mean size: 45 μm; specific mass: 2485 kg/m3 ; (d) Silicon Carbide (SiC); mean size: 45 μm; specific mass: 3110 kg/m3 .

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In