Effects of Lanthanum on Corrosion Resistance of Hot-Dip Galvanized Coating

Effects of lanthanum addition on corrosion resistance of hot-dip galvanized steel were investigated. The coatings containing different contents of La were prepared by hot-dipping process simulator. The corrosion resistance of coatings were measured by salt spray tests, weight loss tests and linear polarization tests. All coatings containing La had excellent corrosion resistance in three types of testing environments. The results indicated that addition of La into the galvanized coatings could not inhibit the formation of white rust, but could inhibit the formation and growth of red rust greatly. The optimal content of La was in the range from 0.04% to 0.07%.