抄録
The corrosion behavior and the degradation of the gray cast-iron pipes, which had been buried for 22 to 79 years and used for natural water, have been investigated. The rate of the graphitic corrosion of pipes was in the range of 0.167 to 0.25mm/yr. The graphitization reduced the real wall thickness so that the strength of pipe was lowered. Therefore, it is possible to estimate the degradation of tensile strength, crushing load, and fatigue strength of a pipe using the relation between its duration buried and graphitization depth.
