Relation between Corrosion Energy and Rolling Fatigue Life with a Four Ball Test

Abstract

The authors evaluated the fatigue life using a rolling four ball test with mineral oil samples in which an alkaline metal, a phosphorus system or a sulfur system compound were added. As a result, it was likely that a decrease of the hardness in the vicinity of the ball surface shortened the fatigue life. Moreover, it was found that the larger the corrosion energy in extract water of the oil sample, the shorter the fatigue life. There is a linear relationship between the corrosion energy and the fatigue life. In addition, the technology to extend the fatigue life and the investigation on additive effect are reported.

Keywords

• corrosion energy
• fatigue life
• rolling four ball test
• nano-indenter
• friction surface hardness