Corrosion of carbon steel in flowing Sulfuric acid

Abstract

Corrosion tests of carbon steel metal in 5% H2SO4 solution at different operating conditions were performed for ranges of temperature (30 to 60 o C) and rotational velocity (0 to 600 rpm) using both weight loss method and electrochemical polarization technique (Tafel extrapolation). The results revealed different trends of carbon steel against the experimental parameters. The corrosion rate was found to increase considerably with increasing temperature for the majority of results. However, increasing rotational velocity clearly enhanced the corrosion rate for carbon steel. The corrosion potential shows sharp decrease with time in first few minutes and then increase reaching an asymptotic value beyond that. In weight loss experiments, increasing temperature shifted the Ecorr to more positive at stationary condition. Increasing velocity from 0 to 400 rpm shifted the Ecorr to more negative at 40 °C. Then trended to positive with increasing velocity to 600 rpm. In polarization experiments, Ecorr shifted to more positive with increasing temperature from 30 to 40 °C and small change when increasing the temperature from 40 to 60 °C. Increasing velocities shifted the corrosion potential to more positive.