Evaluation of Superficial Plastic Deformation Effect on Surface Isotropy of a Low Alloy Steel

The quality of the surface finish is an important element whether in a piece or a mechanical system. The choice of surface finishing process according to its application is essential for manufacturers, ball burnishing is a mechanical surface treatment without removal of material and acts by superficial plastic deformation allowed improve the performance of materials.. The objective of this experimental work is to study the behavior of the surface of a low alloy steel with Chrome Molybdenum after superficial plastic deformation, in this case ball burnishing. To evaluate the effect of latter, two surfaces (P1 and P2) were treated with a load of 8.5Kgf and 20Kgf respectively and 04 passes each, under abundant lubrication. Microhardness and 3D roughness measurements were carried out, where the parameters "Hv", "Sa" and "Str" were estimated respectively. The results show that the Hv hardness was improved by a rate of 35% compared to the initial state. Furthermore, the surface roughness "Sa" was reduced by up to 90% compared to the initial roughness, confirming the beneficial effect of ball burnishing. On the other hand this process seems to have an effect on the surface isotropy in this case "Str" which records a maximum value of 0.546 affirming that the surface texture tends to be isotropic, in comparison with the initial surface which presents according to the polar curve a privileged direction sign of an anisotropic surface.