Reproducibility of electrochemical noise data from coated metal systems

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:490815

Bierwagen, G P; Mills, D J; Tallman, D E ^[1]; Skerry, B S ^[2]

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1. North Dakota State Univ., Fargo, ND (United States)
2. Sherwin-Williams Co., Cleveland, OH (United States)

The use of electrochemical noise (ECN) as a method to characterize the corrosion-protection properties of organic coatings on metal substrates was pioneered by Skerry and Eden, and since then has been used by others as a probe for coating metal corrosion studies. However, no statistical examination of the reproducibility of the data from such measurements has been published. In the data the authors present, they have done a systematic analysis of important experimental variables in such systems. They have examined the method for accuracy and reproducibility with respect to sample preparation, sample immersion, and metal substrate preparation. They have taken several marine coatings systems typical of US Navy use, prepared duplicate samples of coating metal systems, and examined them under the same immersion exposure. The variables they considered for reproducibility are paint application (in three-coat systems), metal panel preparation (grit-blasted steel), and immersion conditions. The authors present ECN data with respect to immersion time on the values of noise voltage standard deviation {sigma}{sub V}, noise current standard deviation {sigma}{sub I}, and the noise resistance R{sub n} as given by {sigma}{sub V}/{sigma}{sub I}. The variation among supposedly identical sample pairs in identical immersion monitored under identical conditions is presented. The statistics of the time records of the data are considered, and the variations with respect to specific coatings classes are also considered within the limits of the data. Based on these data, comments concerning ECN on coated metal systems as a predictive test method are presented along with special considerations that must be made to properly use the method for coating ranking and lifetime prediction.

• Sponsoring Organization: Office of Naval Research, Washington, DC (United States)
• OSTI ID: 490815
• Report Number(s): CONF-9405117--; ISBN 0-8031-2032-X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORROSION PROTECTION
CORROSION RESISTANCE
DATA ANALYSIS
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRICAL TESTING
FLUCTUATIONS
METALS
ORGANIC COMPOUNDS
PAINTS
PROTECTIVE COATINGS