Evaluation of corrosive degradation in coated steel using alternating current impedance spectroscopy
- Univ. of Nevada, Reno, NV (United States)
Alternating current (AC) impedance spectroscopy was applied to measure the degradation of steel coatings previously exposed to corrosive solutions such as tap water and 3% sodium chloride (NaCl). The method used was simple and quick and did not utilize electrochemical (potentiostatic) control. Previously immersed specimens of three types of coated steel were sandwiched between metallic foil electrodes and connected to the impedance measurement instrumentation. Typical Nyquist and Bode plots were obtained showing progressive losses in coating resistance with exposure time. The advantage of the method was that immersion in the electrolyte solution was not necessary during measurements for atmospherically exposed coatings, as required in electrochemical impedance spectroscopy (EIS). As a result, weathered and otherwise degraded coatings in previous atmospheric exposures could be evaluated without the additional effects present during electrolyte immersion in EIS. The method successfully discriminated between low- and intermediate-resistance alkyd and high-resistance epoxy coatings.
- OSTI ID:
- 6495198
- Journal Information:
- Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 51:2; ISSN 0010-9312; ISSN CORRAK
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360105* -- Metals & Alloys-- Corrosion & Erosion
360604 -- Materials-- Corrosion
Erosion
& Degradation
ALLOYS
CHEMICAL REACTIONS
COATINGS
CORROSION
CORROSION RESISTANCE
ELECTRIC IMPEDANCE
EPOXIDES
IMPEDANCE
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MEASURING METHODS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYMERS
PROTECTIVE COATINGS
STEELS
SYNTHETIC MATERIALS
THERMOPLASTICS