Summary of Field Test Findings

The corrosion attack was severest at PI followed by P2 and P3. Corrosion rate decreased with time and the rate of corrosion was lowest for WS at sites for all times. DC measurement on uncoated panels after 42 m exposure showed that corrosion was lowest at P3 on WS and also corrosion potential was greater. In fact, corrosion potential for all the cases was greater for WS than MS. Corrosion rates of MS and WS at P2 were comparable, whereas at PI corrosion rate of MS was lower than WS. Apparently, WS is more vulnerable to chloride ions and the product/rust of WS is also more vulnerable than MS. Again corrosion rate of coated WS after 18 m exposure was much lower than that of MS at P3, even the corr was also greater. AC impedance data of uncoated 42 m exposure corroborated the DC test data and the rust product acquired good resemblance of coatings which can be compared with paint model. 

Effectiveness of rust coatings was tested by EIS and the trend was same i.e., rust coating developed on WS was more protective than MS. However, panels became 

Panel Raman shift (cm ) Phase Published Raman shift (cm ) Ref. Raman shift (em ) Phase Published Raman shift (cm ) Ref 

Panel Raman Phase Published Ref. Raman Phase Published Ref. 

Bold strongest peak in spectrum. Underline next strongest peek in spectmm 

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