Effect of Machining Configurations on the Electrochemical Response of Mild Steel in 3.5% NaCl Solution

The present work is based on the study of the electrochemical response of mild steel as a function of machining configurations. The variable parameters were rake angle and turning speed, while feed rate and depth of cut remained fixed. Dynamic polarization tests and electrochemical impedance spectroscopy in 3.5% NaCl solution were done to analyze the electrochemical behavior of mild steels with the variation of rake angle and turning speed. The electrochemical response showed that the steel machined at higher speed and positive rake angle had higher resistance to charge transfer. Similarly, steel machined at lower speed and negative rake angle showed lower resistance to charge transfer. The results obtained in this study suggest that machining on mild steel should be carried out at positive rake angle and at higher speed to have smoother surface finish, strain-relieved surface grains, and subsequently better corrosion resistance, which was measured from corrosion current as determined by the Tafel extrapolation from the polarization plots.