Surface characterisation, corrosion and mechanical properties of polyester-polyester/snail shell powder coatings of steel pipeline for naval applications

The pure polyester reinforced with snail shell powder (SSp) applications as coating to steel pipeline was carried out. The snail shell powder of size 75 m in the range of 20 wt.% at 5 wt.% interval was used for these coatings. Characterisation of the snail shell powder by X-ray fluorescence (XRF) and morphological surface modification in the absence and presence of polyester and polyester reinforced with snail shell powder were also evaluated by electron microscope. The elements present before and after coatings were investigated. The steel pipelines coated with polyester/SSp being heat-treated at 150 degrees C were investigated for corrosion resistance by Tafel test in seawater. The mechanical and tribological properties of coated and uncoated were also investigated. The corrosion resistance properties of polyester/snail shell powder coatings were significantly improved. This was attributed to the hard coatings after heat-treated. Current density (i(corr)) of the steel pipeline, steel pipeline/polyester, steel pipeline/ polyester reinforced with 10 wt.% and 15 wt.% SSp in seawater was 36.61, 10.47, 9.05 and 0.81 mu A/cm(2) respectively. The hardness values of the formulation of polyester/snail shell powder were improved too. The test shows that addition of snail shell powder increases wear resistance of the coating reinforced with snail shell powder than polyester alone. From the above findings, the steel pipeline coated with polyester/snail shell powder in the range of 10-15 wt.% can be used conveniently in seawater environment.