A Comparative Study of Residual Stress Distribution Induced by Hard Machining Versus Grinding

This study investigates the residual stress distribution induced by hard machining and grinding and compares its impact on fatigue parameters. The residual stress distribution below hard turned and ground surfaces is investigated after a thermally damaged layer is removed. Fatigue parameters are computed based on the residual stress distribution to compare the impact of the residual stress distribution on the fatigue performance. Rolling contact fatigue tests are then performed to substantiate the computations. The effect of residual stresses on crack initiation depth is shown to be significant for the ground specimen. The maximum shear stress at crack initiation depth of the hard turned specimen is smaller than that of the ground specimen. Due to a significant increase in crack initiation life, the predicted rolling contact fatigue life of the hard turned specimen is longer than that of the ground specimen. The overall average in the ratios of predicted life to experimental life for the hard turned specimen is closer to 1 than that for the ground specimen. The results demonstrate that the hard turned specimen shows better rolling contact fatigue performance and better accuracy in the fatigue life prediction.