| 摘要 |
PCT No. PCT/JP97/02318 Sec. 371 Date Dec. 18, 1998 Sec. 102(e) Date Dec. 18, 1998 PCT Filed Jul. 3, 1997 PCT Pub. No. WO98/01603 PCT Pub. Date Jan. 15, 1998In an electrically corrosion-proofing process in which the polarity of a metal member having a coating film is set at negative, the duration of setting the polarity of the metal member immersed in an aqueous solution of NaCl at negative is made discontinuous, and a positive-set duration in which the polarity of the metal member is set at positive, is interposed between a proceeding negative-set duration and a succeeding negative-set duration. The switching-over of the polarity is carried out by a polarity switch-over relay between the metal member and a DC power source. In the negative-set duration, the treatment for corrosion-proofing of the metal member is carried out, but the peeling-off of the coating film from a starting point provided by a damaged portion is produced. In the positive-set duration, an electrolytic product is produced in an exposed portion of the metal member, and the peeling-off of the coating film in the next negative-set duration is prevented by the electrolytic product. Thus, it is possible to carry out the corrosion-proofing treatment of the metal member having the coating film and to inhibit the peeling-off of the coating film by the corrosion-proofing.
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