Pit formation mechanisms in lubricated rolling four-ball tests
2012 (English)In: 15th Nordic Symposium on Tribology - NordTrib 2012: 12 - 15 June 2012 - Trondheim, Norway, Trondheim: Department of Geography, Norwegian University of Science and Technology, 2012Conference paper (Refereed)
Pitting due to rolling contact fatigue is a complex phenomenon and several factors influence its occurrence, particularly under lubricated conditions. A deeper understanding of pit formation mechanisms is needed in order to effectively evaluate the pitting behaviour of different lubricants. The present work focuses on investigating the events that lead to pit formation in the lubricated rolling four -ball test by analysing surface degradation, wear mode, material changes and crack initiation sites etc. These investigations have been conducted using two API - GL5 gear oils. These analyses of pitted balls revealed the formation of a low hardness region beneath the surface of the rolling track due to martensite decay. The formation rate and expans ion of this region was found to differ for the two lubricating oils. Examination of the pitted ball has also indicated that the initial rolling contact fatigue cracks were initiated at or close to the surface.
Place, publisher, year, edition, pages
Trondheim: Department of Geography, Norwegian University of Science and Technology, 2012.
Research subject Machine Elements
IdentifiersURN: urn:nbn:se:ltu:diva-34748Local ID: 9074e8ee-3a17-41b2-9dcb-6e5a66dae369OAI: oai:DiVA.org:ltu-34748DiVA: diva2:1007999
Nordic Symposium on Tribology : 12/06/2012 - 15/06/2012
Godkänd; 2012; 20120830 (andbra)2016-09-302016-09-30Bibliographically approved