抄録
An unusually rapid corrosion leakage occurred in an underground hot spring water pipeline in a volcanic area within about half a year after its laying. The field survey and laboratory tests showed that the abnormal corrosion of the hot water pipeline would have been caused from original macrocorrosion cells, large difference in resistivity due to the difference of moisture contents between upper and lower soil parts round the hot pipe and formation of magnetite on the pipe surface because of the high temperature and the alternative dry and wet condition. As for the protective measures epoxy coating and cathodic protection were studied, and their combination appeared very effective.
