Glycerine-water Solution Humidity-controlling Method and its Effects on SO₂ Atmospheric Corrosion of Hot Galvanized Steel

The action of humidity on SO2 atmospheric corrosion of hot galvanized steel and the affecting factors for the glycerine-water solution humidity control method were investigated thoroughly. The volume ratio of 1/100~1/125 between the glycerine-water solution and the humidity controlling space and the distance no more than 150 mm were suggested from the coupons to the glycerine-water solution. In the same SO2 concentration, the corrosion rate of the galvanized steel increased with the increase of the relative humidity. The zinc coating swelled and peeled from the substrate during the SO2 atmospheric corrosion. The corrosion products showed an acicular and lamellar loose structure.