Inhibitory effect of sodium nitrite on corrosion of lead in 0.1 M sodium hydroxide solution

Abstract

The effect of NaNO2 as an inhibitor for corrosion of lead in 0.1 M NaOH solution has been investigated at different temperatures using the Tafel plot technique. The concentrations of NaNO2 employed are in the range 1-5×10-5. There is a linear relationship between the corrosion potential and the molar concentration of NaNO2. The inhibitory effect of Na-NO2 is mainly due to the increase of the polarization resistance of the metal. With rising temperature the polarization resistance decreases considerably and the corrosion rate increases. The maximum inhibition efficiency is found to be 49.4% at 35°C and 45.9% at 50°C.