Synergistic Inhibition Effect of Rare Earth Ions and Vanillin on Corrosion of Cold Rolled Steel in H₂SO₄ Solution

The synergistic inhibition effect of four rare earth ions (La3+,Ce3+,Ce4+,Nd3+) and vanillin (4-hydroxy-3-methoxy-benzaldehyde) on the corrosion of cold rolled steel (CRS) in 1.0 mol/L H2SO4 solution was studied by weight loss method.The present study revealed that vanillin had a moderate inhibitive effect on the corrosion of CRS in 1.0 mol/L H2SO4 solution,and the inhibition efficiency increased with the concentration.The rare earth ions of La3+,Ce3+,Ce4+ and Nd3+ had a negligible effect in 1.0 mol/L H2SO4,and the maximum inhibition efficiency was not more than 20%.The experiments of incorporation of rare earth ions and vanillin,indicated that Ce4+ and vanillin produced strong synergistic effect on corrosion inhibition for CRS,and the maximum inhibition efficiency was about 95%.However,there was no synergistic inhibition effect between other rare earth ions (La3+,Ce3+ and Nd3+) and vanillin.