Application of EN(Electrochemical Noise) to Evaluate the Protective Properties of Epoxy Coated Steels

EN(Electrochemical Noise)을 이용한 epoxy 도장 강판의 방청 성능 평가

  • Han, Jong-Man (Daewoo Shipbuilding&Marine Engineering CO.,LTD.)
  • 한종만 (대우조선해양(주) 기술연구소)
  • Received : 2009.10.09
  • Accepted : 2009.10.24
  • Published : 2009.10.01

Abstract

Electrochemical methods have been widely used to study the performances and mechanisms for the degradation of organic and inorganic coatings. In this study, EN(Electrochemical noise) measurement was applied to the protective properties and review the parameters analyzed noise signals in the time and in the frequency domain for epoxy resin based coated steels during exposure to hot sea water($40^{\circ}C$) and salt spray for 200 days. It was also found that $R_n$(Noise resistance), $R_{sn}$($f_{min}$)(Spectral noise resistance) and 2H(Hurst exponent) represented the performance of epoxy coated steels. $R_n$ can be determined as the ratio of the standard deviations of potential and current noise signals and is decreased to exposure time. Data qualities can be easily checked by PSD(Power Spectral Density) plot and $V_{psd}$, $I_{psd}$ and $R_{sn}$($f_{min}$) is useful to research the protective performances and mechanisms of coated steels. Hurst exponent represents the degradation of coated steels. But, it is difficult to directly apply the protective criterion to the evaluation of epoxy coated steels used the shipbuilding processes.

Keywords

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