80. Coatings Containing Silica Nanoparticles and Cerium Salts by Sol Gel Applied on Carbon Steel

S. CERÉ; I. SANTANA; A. PEPE,

Niza, Francia

Congreso; 61st Annual Meeting of the International Society of Electrochemistry; 2010

International Society of Electrochemistry

Carbon steel are widely used in industry, however their susceptibility to corrosion limits its applications. One strategy to minimize the corrosive attack is the application of coatings with rare earth (RE) salts as a valid alternative owing to its low toxicity and environmental feasibility. The RE are employed to replace chromate treatments due their high toxicity which tends to their total elimination in the industry.                 Sol gel is a chemical method that allows the synthesis of glass and ceramic materials at lower temperatures than the conventional methods and can be used to obtain thin coatings which, in turn, may be functionalized.                 This work evaluates the synthesis and electrochemical behavior of coating prepared by sol-gel method applied on carbon steel. Hybrid organic-inorganic silica sol-gel coatings were obtained by dip coating in an organically modified silica sol made from hydrolysis of  3-glicidoxipropyltrimetoxisilano (GPTMS) and tetra-orthosilicate (TEOS) as precursors in acidic catalysis. The coatings were doped with cerium salts (Ce(NO3)3) and loaded with silica nanoparticles for improving both the corrosion resistance of the coatings by the inhibitory effect of the salt and by increasing the barrier effect. The coatings were obtained by dip coating onto AISI 1010 carbon steel, producing a two-layer of equally distributed homogeneous film without cracking. The corrosion behavior of the coated samples was characterized by electrochemical tests at various immersion times in NaCl 0.35%m/v. The results show that the coating improves the corrosion resistance of the alloy although the long term performance in chloride containing solution should be improved.