Effect of silicate anion distribution in sodium silicate solution on silicate conversion coatings of hot-dip galvanized steels

► Causes for effect of SiO2:Na2O molar ratio on silicate coatings are studied. ► Distribution of types of silicate anion in solution depends on SiO2:Na2O molar ratio. ► Si-O-Zn and Si-O-Si bonds in coating depend on the polymerization of silicate ions. ► Proper dehydration leads to formation of compact coating possessed good performance.