Corrosion behavior of Al‐brass alloy during erosion–corrosion process: Effects of jet velocity and sand concentration

Abstract

Polarization and electrochemical impedance spectrometry measurements were performed on Al‐brass alloy during the erosion–corrosion process. The erosion–corrosion tests were conducted at various SiO2 particle concentrations between 0–90 g/L and three jet velocities of 3, 6, and 9 m/s under an impingement angle of 90°. At a jet velocity of 3 m/s, the results showed a decrease in the corrosion rate at sand concentrations higher than 20 g/L, which was attributed to the particle rebounding effect. At higher jet velocities of 6 and 9 m/s, a continuous increase in the corrosion rate was observed with sand concentration. The results also showed a higher effect of jet velocity on the corrosion rate as compared with the sand concentration. This was related to the increase in the frequency and energy of the impacts by increase in jet velocity, whereas sand concentration could only affect the impact frequency. The role of impact energy on the corrosion rate was determined by calculation of normalized erosion‐enhanced corrosion rate. At high sand concentrations, the normalized erosion‐enhanced corrosion rate of the alloy was a function of second power of jet velocity as was expected by an equation drove from the energy and frequency of impacts.