Atmospheric Corrosion of Metals in Ichihara Area
1986 Volume 21 Issue 5 Pages 386-395
Details
1986 Volume 21 Issue 5 Pages 386-395
In order to evaluate the atmospheric corrosion of metals in Ichihara area, Chiba prefecture, the relation between the air pollution and the corrosion of metals was investigated from August 1968 to July 1975. The weight changes of the metals were measured such as iron plate, copper plate, aluminium plate, brass plate, and galvanized iron plate. The contents of sulphur deposited on the surface of the metal and sulphur trioxide concentration in sampling area were analyzed by BaSO4 and PbO2 methods respectively. On the other hand, the surface roughness of metals was measured by a roughness meter. Each metal was exposed for three months in sampling area.
Results obtained are as follows:
1. The corrosion of metals exposed in atmosphere changed at sampling sites and the average weight gains of the samples increased as follows; galvanized iron plate (0.0085 g)<brass plate (0.0176 g)<copper plate (0.0232 g)<aluminium plate (0.0264 g)<iron plate (0.06289 g).
2. Copper, aluminium, and brass plates were remarkably corroded at A, B, C sites in winter than in summer, while iron and galvanized iron plates were corroded in summer than in winter.
3. The corrosion metals were compared with the air pollution. The aspect of weight gains by corrosion coincided with the distribution patterns of SO2 concentrations.
4. The weight changes of copper and aluminium plates were correlated with the concentration of SO2 except for iron and galvanized plates in winter.
5. The degree of corrosion in atmosphere was evaluated by the surface roughness of metals corroded.
