A Study on the Corrosion Inhibition Performance of Various Starches for Q235A Steel

Abstract

Eight different varieties of starch were chosen to replace the corrosion inhibitors in order to assess the corrosion resistance and rate of deterioration of Q235A steel using an electrochemical test and the weightlessness method. The metallographic microscope was used to examine the corrosion product surface on the steel plate. The results of the weightless method show that the corrosion rate of 300 mg/L of starch was higher than the concentration of 500 mg/L. As the concentration of H₂SO₄ was 0.5 mol/L, the corrosion rate of 300 mg/L of cassava starch, mung bean starch, and wheat starch solution was higher than the others, which were 72.92 %, 72.89 %, and 72.02 %.The results of the electrochemical test show that the corrosion resistance of 300 mg/L pea starch and cassava starch solution were better in the condition of 0.5 mol/L H₂SO₄, whose self-corrosion currents were 34 μA∙cm^-2 and 26 μA∙cm^-2. Their solution resistance R_S were 1.739 Ω∙cm^-2 and 1.801 Ω∙cm^-2, respectively. In conclusion, the effect of 300 mg/L of tapioca starch and pea starch was better in 0.5 mol/L H₂SO₄ solution.