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Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.17 [2010] >
IJCT Vol.17(2) [March 2010] >
| Title: | Performance of different organic coatings on steel substrate by accelerated and in atmospheric exposure tests |
| Authors: | Saha, Jayanta Kumar
Mitra, P K
Paul, S
Singh, D D N |
| Keywords: | Primers
Organic coating
Atmospheric corrosion
EIS
SEM
Raman spectroscopy |
| Issue Date: | Mar-2010 |
| Publisher: | CSIR |
| Abstract: | Organic
coatings act as a barrier to a corrosive solution and check the transfer of
electrical charge from the corrosive solution. High
performance organic paint systems were applied on plain carbon steel substrate
with two different primers viz.,
epoxy Zn phosphate and epoxy Zn rich. Identical intermediate and top coats were
applied on them having equal dry film thickness. Both uncontrolled long term
testing and controlled laboratory testing were conducted to evaluate the
performance of the coatings. Salt spray, and electrochemical impedance
spectroscopy (EIS), were carried out on fresh coated panels whereas both EIS
and DC polarisation studies were done on the panels withdrawn from field
exposure racks using different electrolytes. Polarisation resistance, coating
capacitance, water absorption, and corrosion potential were studied to
understand the causes of deterioration and to have faster assessment of
durability of these paint formulations. Corrosion products were characterised
by Scanning Electron Microscope (SEM) through morphology and Raman spectra
through phase identification. The
performance of epoxy Zn phosphate base primer is very much comparable with
epoxy Zn rich base primer. The findings were supported from the tests conducted
on the panels exposed for two years under the industrial climatic conditions.
The rust formed under the atmospheric condition is non protective
lepodocrocite. |
| Page(s): | 102-110 |
| ISSN: | 0975-0991 (Online); 0971-457X (Print) |
| Source: | IJCT Vol.17(2) [March 2010]
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