| 摘要 |
Draft surface of a structure on or under water surface is equipped with an electrical or electrochemical corrosion-inhibiting means (7). Antifouling metallic tiles (14A) are attached through an electrical insulating layer (13) to the draft surface so that they do contact each other along their surface direction. - Structure, e.g. a ship, dolphin or gate, is protected from both corrosion and deposition of aquatic life. If an antifouling metal piece come into electric contact with a projecting part of the structure, a galvanic current flows to the antifouling metal piece because of the formation of a short circuit. As a result, the structure is affected by abnormal local corrosion. This corrosion can be inhibited by providing a sacrificial anode in electrical contact with the structure to allow an electrical current (ip) to flow from the anode (7) to the antifouling metal piece. However, by the electrical current, the antifouling metal piece is cathodically polarised, and the supply of antifouling ions is stopped. These defects are not eliminated by attaching many antifouling metal tiles through an insulating layer to the structure. Since the metal tiles are independently existing on the insulating layer, the distribution of current density is made uniform without formation of short circuits. Consequently, the structure is affected by general corrosion instead of a local one.
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