35 mass% MgCl2水溶液を用いたSUS304ステンレス鋼の応力腐食割れ試験において観測される腐食電位振動
1994 年 43 巻 494 号 p. 1400-1404
詳細
1994 年 43 巻 494 号 p. 1400-1404
Corrosion potential fluctuation of SUS304 stainless steel during stress corrosion cracking (SCC) was observed in a 35 mass% MgCl2 (353K) solution. The potential fluctuation was measured against an Ag/AgCl reference electrode with a digital voltmeter at a sample frequency of 2.56Hz. During the propagation stage of SCC, a trapezoidal potential fluctuation was observed, whose amplitude and frequency were about 1mV and one or a few times each 3.6ks, respectively. When the experiment was carried out without loading, the trapezoidal potential fluctuation was not detected. The effect of solution temperature on the corrosion potential fluctuation was also examined. An amplitude and an occurrence frequency of the trapezoidal potential fluctuation decreased with a decrease in temperature. The critical temperature for the SCC in the chloride solution environment had been reported to be 323K. The trapezoidal potential fluctuation disappeared at the temperature lower than 333K. Therefore, it was estimated that the trapezoidal potential fluctuation was only generated during the propagation stage of SCC.
