Control of Grinding Surface Residual Stress of Inconel 718

The grinding surfaces of the nickel-based superalloy usually generate tensile residual stress, which may reduce fatigue life of components. In order to transform tensile stress to compressive stress, this research develops a new technology that embeds a heat source inside the workpiece during grinding. The grinding process of Inconel718 is simulated by using COMSOL Multiphysics 5.0, and the distributions of residual stress with and without the added heat source are obtained. In addition, the influence of the density heat source, the length of heat source, the height of heat source and the distance between heat source and grinding zone on the residual stress are studied. The results are as follows: (1) The surface tensile residual stress can be transformed to the residual compressive stress by embedding a heat source in the workpiece. (2) The surface compressive residual stress is most sensitive to the density of heat source. (3) The maximum surface compressive residual stress is obtained by adjusting the density and position parameters of heat source.