Abstract
The corrosion of bronze joints - used with stainless steel pipes and many of which remaining in the ground - has been one of the causes of water leakage. Therefore this paper evaluates the progress of galvanic corrosion between stainless steel pipes and bronze joints-equipped pipe to soil potential. First, we measured spontaneous potential of four metals used for service pipes and distribution pipes in six kinds of soil at a laboratory. The result showed that each spontaneous potential varied considerably with passage of time, then the order of the potentials was approximately SUS316 > bronze > lead > ductile cast iron, after four hundred days. In addition, we measured pipe to soil potentials and maximum corrosion depths of 318 pieces of stainless steel service pipes dug mostly in Tokyo area. The result showed that the proportion of corroded bronze joints and the maximum corrosion depth increases with an increase in pipe to soil potential.
