Rolling contact fatigue life of finish hard machined surfaces : Part 2. Experimental verification

A rolling contact fatigue life model encompassing crack initiation life and crack propagation life was developed in Part 1 of two companion papers. This paper concerns the experimental verification of the developed life model. The specimens were machined by using various machining conditions and at two different cutting tool conditions: new and worn tools. The experimental results indicate that tool wear, as well as the machining conditions, greatly influences the micro-hardness and residual stress distribution below the machined surface and thus the rolling contact fatigue life. Tool wear induces a highly variable change in fatigue life depending on the machining conditions. The predicted lives by the developed life model show good agreement with the experimental lives, although the experimental lives of the specimens show significant variation.