Monitoring and measuring corrosion under coating by optical interferometry
- KISR, Safat (Kuwait). Materials Application Dept.
In a previous study, a mathematical model relating surface and bulk behaviors of metals in aqueous solution has been developed. The model was established based on principles of holographic interferometry for measuring microsurface dissolution, i.e. mass loss, and on those of electrochemistry for measuring the bulk electronic current, i.e. corrosion current. In the present work, an optical corrosion-meter was built based on the above model. The corrosion meter consists of an electrochemical cell in which coated metallic samples are tested in aqueous solutions. Furthermore, the corrosion meter has a holographic camera with a thermoplastic film for in situ processing holograms in order to obtain real time-holographic interferograms of the sample in the electrochemical cell. During experiments, the samples remain in aqueous solution without any physical contact. In the meantime, corrosion data can be obtained from the interpretation of the interferograms of the sample as a function of the elapsed time of the experiments. Also, the open circuit potential of the sample is measured with respect to the interferometric data. Consequently, corrosion current density of epoxy coated aluminum, stainless steel, and low carbon steel in 1M KCl, 1M NaCl, and 1M NaOH solutions were obtained by using the optical corrosion-meter. A comparison between the corrosion data of the different alloys showed that the corrosion current density of the coated stainless steel in 1 M NaCi is nearly three fold higher than that of the coated carbon steel in 1 M NaOH. In contrast, the coated aluminum sample shows no sign of corrosion in 1M KCl.
- OSTI ID:
- 367737
- Report Number(s):
- CONF-960389-; TRN: IM9640%%483
- Resource Relation:
- Conference: National Association of Corrosion Engineers (NACE) annual corrosion conference and exposition: water and waste water industries, Denver, CO (United States), 24-29 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of Corrosion/96 conference papers; PB: [6615] p.
- Country of Publication:
- United States
- Language:
- English
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