EXTERNAL POWER SOURCE-TYPE ELECTRIC ANTICORROSION METHOD FOR REDUCING DETERIORATION OF STRUCTURE AROUN ANODE IN SEAWATER ENVIRONMENT OF THE LIKE

摘要

PROBLEM TO BE SOLVED: To suppress the generation of gaseous chlorine from an anode at the time of applying a corrosion protection current and to reduce the deterioration of the peripheral structure around the anode due to the exposure to gaseous chlorine, by using an oxygen-selective anode as the insoluble anode for the external power source- type electric corrosion protection device in a seawater environment. ;SOLUTION: The insoluble anode is confronted with the surface of a metal in seawater through the seawater as an electrolyte, a current is applied from an external power source to uniformizing the potential on the metal surface, and its corrosion is prevented. An oxygen-selective anode is used as the insoluble anode for the external power source-type electric corrosion protection device. An MnO₂-base durable electrode, etc., having the amorphous manganese dioxide surface or delta-manganese dioxide surface having ≤1% chlorine generation efficiency are used as the oxygen-selective anode. In this case, H₂O→1/20₂+2H²+2e^- is more dominant than 2Cl^-→Cl₂+2e^- as the the anodic reaction in the seawater, and the deterioration of the peripheral structure of metal, resin, etc., around the anode due to the exposure to gaseous chlorine is reduced.;COPYRIGHT: (C)1998,JPO