Extractos naturales como inhibidores verdes de la corrosión del acero

S.T. BOGDAN; S. ROSELLI; R. ROMAGNOLI; C. DEYÁ

Concepción

Congreso; 15º Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales, CONAMET / SAM; 2015

SAM - CONAMET

Corrosion is an inevitable process of metal deterioration, but feasible to be controlled. Although various methods can be employed for this purpose, the use oforganic coatings or soluble inhibitors in the corrosive medium are a commonly alternative because of their low cost, easy implementation and maintenance. Astraditional inhibitors of the corrosion process are toxic, there is an increasing interest in exploring new efficient, economic and ecofriendly inhibitors.The aim of this study is to evaluate ethanolic extracts of eucalyptus (Eucalyptus globulus), pink peppercorns (Schinus molle) and paradise (Melia azedarach) assteel corrosion inhibitors in sodium chloride medium [1,2].To evaluate the anticorrosive efficiency, polarization curves of SAE 1010 steel were carried out at 2h and 24h of immersion in 6.6 % v / v of each of the extractsin 0.5M NaCl. A solution of 6.6 % v / v of ethanol in 0.5M sodium chloride was used as a blank. Steel corrosion potential in the inhibitory ethanolic solutionswas monitores during 24h. Afterwards, the exposed area was observed by SEM and its element composition determined by EDX analysis.Results show that extracts of eucalyptus and of pink peppercorns reduce steel corrosion rate about six times, although the corrosion potential is shifted to morenegative values in the case of eucalyptus. Paradise extract shifted steel corrosion potential to more positive values, but no significant changes were detected inthe corrosion rate when compared with the blank.Extracts of eucalyptus and pink peppercorns could be used as soluble corrosion inhibitors of steel or they could be incorporated in the formulation of ananticorrosive paint.