Interpretation of Electrochemical Noise Data

CORROSION ◽  
2001 ◽  
Vol 57 (3) ◽  
pp. 265-285 ◽  
Author(s):  
R. A. Cottis
CORROSION ◽  
2000 ◽  
Vol 56 (9) ◽  
pp. 928-934
Author(s):  
G. Miramontes de León ◽  
D. C. Farden ◽  
D. E. Tallman

Abstract A new approach for the measurement of noise resistance based on the transient behavior of pitting corrosion is presented. Potential noise and current transients have been recognized as a characteristic behavior of pitting corrosion. This new approach uses the transient information present during corrosion as a way to estimate the noise resistance of coated metals directly. Computer simulation and analytical results are presented, indicating that the new technique can be applied to the problem of noise resistance estimation. This new approach was applied to experimental electrochemical noise data obtained with commercial electrochemical impedance spectroscopy (EIS)/electrochemcial noise measurement (ENM) equipment.


2004 ◽  
Vol 04 (03) ◽  
pp. R39-R55 ◽  
Author(s):  
G. MONTESPERELLI ◽  
G. GUSMANO

This paper gives an overview of the use of Electrochemical Noise (EN) for corrosion studying and monitoring. Since the quality and reliability of noise data are affected by a number of acquisition parameters, such as sampling interval, sampling duration, D.C. trend and instrumental noise, some experimental and practical aspects were discussed. The use of statistical parameters such as standard deviation, Pit Index and/or Localization Index and Noise Resistance to analyze noise data of corroding systems were examined. Many experimental applications of Electrochemical Noise Measurements on different metals and alloys were given. EN data have been compared with traditional electrochemical techniques. EN allowed to characterize the corrosion behavior of samples giving in some cases good quantitative estimation. The transposition of current and potential noise acquisition in the frequency domain (by Fast Fourier Transform and/or Maximum Entropy Method), gave further information on corrosion mechanism and in particular permitted to identify the type of corrosion. Finally the use of Discriminant Analysis permitted to deduce the best sampling frequency and sampling duration for EN acquisition, able to discriminate between two different situations.


2007 ◽  
Vol 53 (2) ◽  
pp. 680-687 ◽  
Author(s):  
J.Y. Huang ◽  
X.P. Guo ◽  
Y.B. Qiu ◽  
Z.Y. Chen

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
A. P. Shashikala ◽  
J. Ramasubramanian ◽  
G. Janakiraman

The random nature of sea waves and the aggressive corrosive environment of seawater make corrosion an important factor in deciding the safe operational life of offshore steel structures. The consistent rise in offshore oil exploration activities in the last 2 decades has compelled structural engineers and researchers to better understand, the process of corrosion in offshore steel structures. The various electrochemical methods available for corrosion monitoring are polarization, electrochemical impedance spectroscopy and electro chemical noise (ECN) techniques. In offshore industry, the reliable interpretation of electrochemical noise is particularly valuable since it promises new type of online monitoring device. This paper introduces ECN as an online corrosion-monitoring tool for marine structures. The paper discusses the laboratory experiments conducted on test specimens to collect data related to the electrochemical behavior of structural steel such as the polarization data, impedance measurements, electrochemical, potential, and current noise measurements. Investigations were carried out on MS coupons surface prepared and coated with anticorrosive and antifouling paints. An electrochemical workstation capable of collecting data from specimens coated with paint was used for noise data collection. Static corrosion tests have been done and the corrosion rate and corrosion resistance of the coatings were assessed using the statistical analysis. The electrochemical noise data were compared with that of polarization and impedance data and a good correlation between corrosion rates was obtained. The polarization and noise resistance were found to be similar in trend but with variation in numerical values. Statistical parameters like mean, standard deviation, skew, and kurtosis were generated from the obtained noise. These parameters were then processed to obtain noise resistance and corrosion rate. The results were compared with that of polarization and impedance values. The corrosion rate comparison showed a deviation of 10% from polarization with ECN giving the upper bound values. The damage prediction and expected life prediction of a steel jacket platform were also performed using the data collected. The experiments showed a good correlation between the noise resistances obtained from various electrochemical methods. The aim of introducing the ECN as an online monitoring tool for marine structures especially in on-life offshore structures gives valid data with good results and shows good sensitivity.


2006 ◽  
Vol 19 (14) ◽  
pp. 1402-1409 ◽  
Author(s):  
C. Aldrich ◽  
B.C. Qi ◽  
P.J. Botha

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