二つの不溶性陽極による水中鋼帯の陰極防食に関する研究

抄録

Cathodic protection method which can be applied to all of metals in water and in underground is one of the most economic and desirable protection methods. However, it sometimes occurs that a part of cathodic metal is over-protected and the other part is protected insufficiently because the distribution of cathodic potential is not even equal, depending on the position of anodes under cathodic protection process. In this paper, it was investigated how a cathodic potential distribution was influenced with the cathodic current density applied on the metal and distance between anode and cathodic metal protected. And the most desirable protection condition was found from the results. The results obtained in this study were as follows.
1) A cathodic potential distribution was changed with apparent applied cathodic current density (I₀) and the anode height (h).
2) A proportion factor (k) decreased with increasing of anode height (h), and the cathodic polarization potential on the center point of a cathodic metal increased with increasing of that, which is considered to be attributed to a Throwing power.
3) In the case of the solution with comparatively high specific resistance like the solution used in this experiment, it is necessary to give a large (h) and (I₀) to protect all parts of cathodic surface.
4) The most optimum values of (h) and (I₀) were 0.4m and 32×10^-2A/m² respectively, in the solution with specific resistance of 22.1Ω·m.