Protection of material applied in heat exchanger under submerged jet impingement condition with Boswellia serrata: electrochemical approach

Abstract

Erosion–corrosion of 6061 aluminum alloy was attenuated with a green inhibitor Boswellia serrata (BWS) under submerged jet impingement condition by using artificial seawater slurry. Erosion–corrosion rates in the absence and in the presence of inhibitor were achieved by potentiodynamic polarization techniques (PDP). Experiments were performed under the varying concentration of inhibitor at different flow rates and temperatures. Conditions were optimized to obtain maximum inhibition efficiency. Mechanistic aspects of the corrosion and inhibition process were studied in detail by the electrochemical impedance spectroscopy (EIS) technique by correlating the data with appropriate equivalent circuit models. Adsorption of inhibitor was confirmed by surface morphology studies using scanning electron microscopy technique (SEM). Suitable mechanism was proposed for corrosion inhibition process. The inhibition efficiency increased with an increase in its concentration and it decreased with an increase in the flow rate and temperature. The inhibition efficiency of 70% was obtained for 1000 ppm of inhibitor at 303 K at the flow rate of 4 L min−1. It was proved that the mechanism of corrosion inhibition under this tribological condition is charge transfer controlled. The effect of hydrodynamics on the inhibitor efficiency of Boswellia serrata extract was remarkable. Boswellia serrata emerged as an efficient green inhibitor of erosion–corrosion control of 6061 aluminum alloy under submerged jet impingement conditions. Graphical abstract