The objective of this work is to achieve an analytical predictive model to study the influence of surface topography on the corrosion resistance of UNS S31600 stainless steel, in a solution of sodium chloride NaCl, at 6% by weight as electrolyte, applying the finite element method. The surface topography was given by the average roughness variation of a UNS S31600 work piece in superfinish turning, of which correlation with the corrosion resistance was examined. The analytical results show that corrosion physico-chemical parameters, polarization resistance, corrosion rate, corrosion potential, and current density have a very remarkable correlation with the surface roughness obtained by the superfinish turning. This is due to a very significant affinity between the plastic deformation depth obtained by turning, and the pits development on the work piece surface. The whole work was completed by an empirical analysis, in order to validate the analytical results obtained in comparison with the experimental results.Keywords: Pitting corrosion; finite elements; arithmetic roughness; superfinish turning; potentially dynamic test.
IntroductionSuperfinish turning is a machining process that has become more important in the mechanic industry. It consists in avoiding the rectification phase, in order to have a good machined surface quality. This process is developed in mechanical engineering, especially when the work piece's functional performance and lifetime are essential requirements. Numerous experimental and analytical studies have been carried out to quantify the influence of these cutting conditions on the surface texture [1,2,3], residual stresses [4,5,6] and microstructure [7,8] of metals and metal alloys.