Abstract:WC-12Co coating was prepared by HVOF on 316L substrate and its corrosion mechanism in mol-ten zinc was investigated .The results showed that the WC-12Co coating was uniform and dense with the porosity less than 1, ,and the coating has good corrosion resistance to molten zinc with the average micro hardness exceeded 1300 HV0 .3 .The crack occured due to the residual stress and thermal stress in the coat-ings ,the molten zinc corroded the substrate by penetrating the crack ,resulting in the coating peeling off from the substrate .