With a view to the important effects of
additives on the quality and corrosion resistance of cerium
conversion coating, the
corrosion behavior of cerium
conversion coating in a Cl~- containing solution was investigated using weight loss method. The effects of the additives such as hydrogen peroxide, sodium chloride, and sodium benzoate were studied. The results showed that in the absence of the additives, the thickness and
corrosion resistance of the cerium conversion coating gradually increased with increasing concentration of Ce(NO_3)_3, while the corrosion rate of the cerium conversion coating gradually decreased therewith and kept almost unchanged at a concentration of Ce(NO_3)_3 above 0.003 mol/L. Hydrogen peroxide had no effect on the quality of the cerium conversion coating. Sodium chloride was able to improve the quality of the conversion coating, while sodium benzoate was the most effective in terms of the ability to improve the quality of the cerium conversion coating. Moreover, the additives had little effect on the coating thickness under the same Ce(NO_3)_3 concentration.