Scuffing Failure of Steel Discs: Conditions for the Failure of Elastohydrodynamic Lubrication

Scuffing tests run on circumferentially finished discs were analysed to determine the conditions for the failure of elastohydrodynamic lubrication according to Dyson's theory. The critical lubricant temperatures and viscosities derived from this analysis were compared with the temperatures and viscosities at atmospheric pressure and at the bulk temperature of the discs, as recorded by thermocouples embedded below the surfaces. Tests and corresponding calculations were made for three different lubricating oils and for two steels. The results of the comparison between measured and calculated critical temperatures and viscosities support the concept of scuffing failure as being related to the physical failure of elastohydrodynamic lubrication, even though the lubricants differed significantly in their scuffing behaviour.