Abstract: The effect of C and Si content on the corrosion process in the steel used for galvanizing vessel was researched.The microstructure and phase constitution of the corrosion layer formed in the liquid zinc was analyzed by SEM.It has been found that the ζ phase firstly formed at the interface between Fe and Zn.With C and Si content increasing, the Гphase disappears, and the δphase zone also becomes thinner, and the ζphase with rapidly growing feature forms.At the same time the corrosion rate will increase obviously. Based on these studies, a new welding consumable used for the 08Cu steel, which is used for the manufacture of the galvanizing vessel, was developed.The harmful C and Si in this consumable were consumed by the self-oxidation action of some oxidants.This welding consumable can provide a weld metal with lower C and Si content and satisfactory corrosion resistant property.