Experimental study for optimizing superfinishing process parameters of high-quality alloy bearing steel

Abstract

Superfinishing is one of the methods of high-quality surface machining of elements subjected to high surface wear. It is used for machining external and internal cylindrical surfaces using various models of tools. This experimental study was aimed at determining the effect of machining parameters on surface roughness of high-quality alloy bearing steel. The factors considered were angle of crosshatch pattern (realized by the rotational speed at constant velocity and oscillation), machining time, and pressure of the tool on the machined surface. The experiment was carried out according to the analysis planned for two tools with granulations of 500 and 800. The polynomial and exponential regression equations for subsequent roughness and performance parameters were determined statistically. The multidimensional correlations based on the t-student distribution were established. The results showed that the optimum surface quality depended on the process parameters: grain size, machining time, crosshatch angle, and the contact pressure. The time at which the machining process starts to stabilize with a steady surface roughness was determined to be 120 s. The maximum enhancement of surface roughness was 75% for crosshatch angle of 13°, contact pressure of 0.21 MPa, and granulation of 800. For both 500 and 800 granulations, the diameter loss was in the range of 1–12 microns.