APPARATUS FOR PREVENTING CORROSION OF STEEL STOCK

PURPOSE:To effectively exhibit corrosion preventing effect at damaging of film coated part without obstructing contamination preventing action at exposed metal part, by providing conductive layers of >= one layer at intermediate coated layer and conductive means between the conductive layer and a steel stock. CONSTITUTION:If a part 9 of coating, e.g. electrical insulating layers 3, 5 and the conductive layer 4 is damaged by some reason when surfaces of a contamination preventive metal 2 such as Cu(alloy) nobler than steel and the layer 5 are brought into contact with and the steel stock 1 is brought into contact with a sea water 12, a corrosion current 10 flows in case the layer 4 is absent. But by providing the layer 4, a current 11 larger than the current 10 is generated along the course from a source 8 to a conductive wire 6 the layer 4 the stock 1 a conductive wire 7 through the layer 4 to suppress the current 10 and corrosion at damaged part is suppressed. Further, hard components Ca , Mg in the water 12 are deposited as CaCO3, Mg(OH)2 by the current 11 on the stock 1 surface of damaged part to repair the layer 3 and continuous flow of the current 11 is prevented.