Abstract
Topographic measurements of rusted, pretreated and several coated steel surfaces were done employing non-contact 3D optical surface profiler. A laser displacement sensor technique was applied in this technique. This method efficiently and quantitatively evaluated surface topographies and curves of cross-sections of pretreated and anticorrosive coated surfaces. The results indicated that pit formed during SST (Salt Spray Test) was grown as a result of initiation and then further blistering upon exposure to SST. The area ratio of these blisters were successfully measured by 3D topographic study without any inference from surface outflow rust. It was found that the blistering area ratio depends on various factors like coating condition, nature of paint, coating thickness etc.
