定電流分極による塗装鋼の腐食挙動の研究
1986 年 35 巻 5 号 p. 263-269
詳細
1986 年 35 巻 5 号 p. 263-269
The corrosion behavior of painted steels with various surface conditions was studied using the galvanostatic polarization technique in a 3% NaCl aqueous solution at 25°C. The polarization curve obtained was of the mixed control type. At an initial immersion stage, icorr was as small as 2×10-5 to 2×10-6A/m2, but after a certain time (critical time), it increased sharply up to 10-3A/m2. The blistered area also increased. The corrosion resistance could be estimated from the critical time. It was in the order of polished-phosphated>rusted-phosphated>polished>rusted. The fastest corrosion reaction of the rusted painted steel could be attributed to the reduction of FeOOH in rusted layer to Fe3O4.
