抄録
In order to make clear the effect of volcanic environment on the corrosion of metals, corrosion tests where heating and cooling are repeated between 40°C and 20°C in SO2 gas atmosphere (150-200ppm) were carried out on the specimens, carbon steel (SS 41), copper, aluminium, and zinc-plated steel which were covered with volcanic ash on the surfaces. The corrosion phenomena were investigated by means of the measurement of mass loss for corrosion and electron probe microanalysis. For SS 41, aluminium, and zinc-plated steel, the corrosion is greatly accelerated by volcanic ash when it accumulate thick on the surface. The copper specimen corrodes faster in the case of no volcanic ash, while under the presence of volcanic ash the corrosion is greatly accelerated as volcanic ash layer becomes thicker. These effects of volcanic ash on the corrosion are attributed to capillary condensation and water-retaining effects of volcanic ash layer.
