Impact of some agro fluids on corrosion resistance of mild steel

Abstract

The corrosion behavior of mild steel in apple, mango, grape, orange and the mixture of these agro fluids were electrochemically studied. Chemical compositions of both mild steel and the agro fluids were carried out to determine the corrosion mechanism for the reaction. Polarization behaviors of mild steel in the agro fluids were determined by Tafel extrapolation curves over the interval of five days for a sixty-day immersion period at a constant temperature of 27 ± 2 °C. The cathodic polarization curves were almost identical irrespective of variation in concentration of the various fluids while the anodic polarization curves exhibited varying active and passive corrosion behavior. Also, the corrosion rates of the alloy decreased with increase in immersion period which could be due to gradual decline in the concentration of the acidic level in the fluids within the given range of potentials. Hence, the evolution of hydrogen gas and reduction of oxygen molecules from the reacting system were presumed to be major factors decreasing corrosiveness of the solution involved. SEM and EDS analysis of the corroded mild steel showed the respective compositions of the mild steel after the electrochemical tests. The result obtained from the study showed that electrochemical corrosion rate over the duration of immersion was in a range of mixture of the fluids > orange juice > grape juice > mango juice > apple juice.