Abstract：The formation theory of continuous hot-dip galvanizing layer is introduced, and the thickness of Fe2Al5 metal compound is the fundamental factor affecting the zinc layer adhesion.The process factors affecting the coating adhesion are studied, including: the raw material surface state, the atmosphere in the annealing furnace, zinc liquid composition, zinc liquid temperature, etc.Corresponding measures are formulated for different influencing factors: control the residual oil content of hot dip galvanized substrate below 100mg / m2, and the residual iron content below 100mg / m2.Inside the control annealing furnace is N2 and 2%H2 with oxygen content less than 10ppm.The Al content in the control zinc solution was 0.20% – 0.21%, and the zinc liquid temperature was 455±3℃.
2022, Vol. 29 