Evaluation of coating degradation for polymer coated steel exposed to seawater
- Univ. of Southern California, Los Angeles, CA (United States)
- Naval Surface Weapon Center, White Oaks, MD (United States)
- Naval Research Lab., Stennis Space Center, MS (United States)
Three sets of polymer coated steel were exposed to Pacific ocean water (NS) and artificial (AS) sea water. Each set had a different primer -- metallic zinc, IVD-Al or phosphate. Within each set one group of samples had an epoxy coating, the other set had an additional layer of polyurethane as a topcoat. Degradation of the protective properties of the polymer coating was followed by recording impedance spectra and electrochemical potential and current noise data as well as by visual observation. Statistical analyses concerning the effects of the nature of the primer, presence of a topcoat and exposure medium (biotic vs. abiotic) were performed based on the breakpoint frequency f{sub b} obtained from impedance data and the noise resistance R{sub n} and the spectral noise resistance R{sup o}{sub sn} obtained from noise data. Samples exposed to three different colonies of microorganisms containing sulfate reducing-bacteria (SRB) and a control solution were evaluated using electrochemical impedance spectroscopy (EIS). All samples were examined by environmental scanning electron microscopy (ESEM) to determine biofilm distribution and spatial relationships between coating damage and microorganisms.
- OSTI ID:
- 379722
- Report Number(s):
- CONF-960389--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Assessing performance of painted carbon and weathering steels in an industrial atmosphere
Corrosion resistant coatings from conducting polymers