2017 Volume 66 Issue 11 Pages 357-360
Permeated hydrogen from scratches （0 mm2, 0.3 mm2 and 1.5 mm2） formed on zinc coated steels was measured by electrochemical hydrogen permeation technique with wet and dry cycle corrosion tests. Independent of the area of the formed scratches, the hydrogen permeation current with similar shape was measured. The white corrosion products were observed after the tests. The hydrogen permeation charges increased with cycle number up to 3, and thereafter it was decreased with the cycle number. The corrosion products around the formed scratches were simonkolleite （Zn5（OH）8Cl2･H2O）. It was suggested that the formation of simonkolleite is the possible reason for decreasing the hydrogen permeation current for longer wet and dry corrosion tests. Comparing hydrogen permeated charge from 1st to 3rd cycle and scratch area, it was suggested that generated hydrogen does not uniformly permeated into steel substrate at the scratch.
