Panel Discussion on Contact Fatigue

P. M. Ku
1976 Journal of Lubrication Technology  
running tracks. A similar study of surface profiles of test specimens run in mineral oil and mineral oil plus ZDP for evidence of wear could yield important evidence for this mechanism. Have any measurements of this type been made since they are critical to the discussed mechanism and the analogy with four-ball wear test data in Part III? Authors' Closure Reply to Part III Discussion The authors would like to thank the discussors Beerbower, Ku, Murphy, and Rowe for their stimulating discussion.
more » ... ulating discussion. One common thread in all the three discussions is the effect of viscosity and pressure coefficient (a) on pitting fatigue life, as revealed in equation (2) of Part II. The apparent contradictions thrown up by equation (2) are obvious and challenging. In responding to this challenge, both Drs. Ku and Beerbower have suggested that the reasons may be found in some chemical effect at the surface. We support this and would liKe to suggest that extreme surface distress and related chemical corrosion effects are expected in most of these tests. Equation (2) is based on 380 tests (Phase I and II data) with a X(/i m in/CLA c ) ratio less than unity in 90% of the tests. Wellauer and Holloway 7 using a composite surface roughness, S' (average of two rms values) which is about 1.3 times CLA C , show that when X(h/S') is less than 0.7, boundary lubrication prevails and lubricant, surface physical and chemical interactions, load and temperature control distress
doi:10.1115/1.3452837 fatcat:frad6e6zlzfyplsmuzs6747h6i