“…In the system, the effect of flow-rate and time on the polarization curve can be taken into account for defining the boundary conditions. Key words : boundary element method (BEM), 2D, 3D, axi-symmetry, potential, current density, catholic protection, galvanic corrosion, polarization curve, seawater, pump (2-1, Honfujisawa 4 chome, Fujisawa, 251 Japan) (11-1, Haneda Asahi-cho, Ohta-ku, Tokyo, 144 Japan) (12-1, O-okayama 2-chome, Meguro-ku, Tokyo, 152 Japan) (Manuscript received December 27, 1996 ; in final form February 24,1997) …”