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The hydrogen permeation behaviour of DP and Q&P grades of advanced high strength steels was investigated using the permeability experiments(1)under cathodic charging at different potentials in 0.1 M NaOH solution,(2)in 3%NaCl solution at the free potential simulating the corrosion behaviour of non-galvanized steel in service and(3)at zinc potential for the corrosion condition of the galvanized steel during actual service.Under cathodic charging at different potentials in 0.1 M NaOH solution,hydrogen permeation decreased with less negative charging potential,reflected by lower values of permeation rate and diffusion coefficient.At the most severe charging condition of –1.700 VHg/HgO in the 0.1 M NaOH solution,the permeation rate for 1200 DP-GI steel was 1.53 μA/cm and for 980 QP steel was 0.492 μA/cm.The values for 1200 DP-GI and 980 QP steels at the least severe charging condition of –1.100 VHg/HgO were 0.178 μA/cm and 0.111 μA/cm,respectively.The hydrogen permeation rate under simulated service conditions in 3%NaCl solution was significantly lower than the value under the least negative cathodic charging potential of –1.100 VHg/HgO in NaOH solution.The Zn coating on the 1200 DP-GI steel could protect the substrate steel from corrosion,however,once the Zn coating was corroded under actual service,more hydrogen would be introduced into and permeate through the steel.