Investigation into Burnishing Process to Examine Effect on Surface Integrity, Wear and Corrosion Resistance of Carbon Alloy (EN31) Steel

Residual stress and surface finish are prominent members responsible for service attributes of component, like wear resistance, corrosion resistance and fatigue life. This leads to investigate ball burnishing as a supplementary process to enhance durability of component. Burnishing is a well-known, inexpensive yet powerful superfinishing process that includes plastic deformation of surface layer, resulting in cold working which improves mechanical properties and extend components operational life. The aim of the current examination is to investigate and optimize ball burnishing process by Taguchi integrated PCA technique for finding most feasible combination of process variables to decrease specific wear rate and increase corrosion resistance of EN31 steel components. Post-burnishing, hardness improved from 178.5 to 265 Hv and roughness of surface reduced from 0.439 to 0.091 μm. The optimization findings revealed that 52% improvement in wear resistance as compared to the turned surface. X-ray diffraction shows that compressive residual stress was induced exactly under the burnished surface. The observed polarization curves and surface micrographs demonstrate that corrosion resistance is improved and consistent. The results confirm that ball burnishing technique enhanced the functional properties of EN31 steel.