The role of chloride ion on the atmospheric corrosion of steel and corrosion resistance of Sn-bearing steel

► We studied the role of chloride ion on the atmospheric corrosion of steels. ► The minute anode chamber simulating local anode sites on steels was set up. ► The chloride concentration affects the pH decrease in the anode chamber. ► The atmospheric corrosion model is proposed. ► Sn-bearing steels exhibit the superior atmospheric corrosion resistance.