Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4986526 | Wear | 2017 | 29 Pages |
Abstract
The influence of lubricant additives on rolling contact fatigue crack propagation and the mechanisms responsible for the resulting micro-scale damage, was studied via experiments conducted on complete transmissions in a test cell. Bench-scale tribological tests and the exposure of steel surfaces to two different formulated lubricants were also carried out. Scanning and Transmission Electronic Microscopy observations, Electron Dispersive Energy and X-ray Photoelectron Spectroscopy analyses indicated that the sulphur present in the extreme pressure (EP) additives has a positive impact on limiting damage propagation. Thanks to TEM observations of cracks, it was demonstrated that a sulphur rich film is formed at the crack tip. This film can act as both a barrier film towards hydrogen permeation within the metal and / or as an inhibitor of oil decomposition. The latter is associated with the nascent surface's ability to limit hydrogen generation. Without such hydrogen embrittlement, crack propagation is slowed down.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Benoit L'Hostis, Clotilde Minfray, Marion Frégonèse, Catherine Verdu, Benoit Ter-Ovanessian, Béatrice Vacher, Thierry Le Mogne, Frédéric Jarnias, Alder Da-Costa D'Ambros,