Per: lucas menezes de souza (universidade estadual do norte fluminense darcy ribeiro (uenf) ), Sthefanie de carvalho mendes lopes (UNIVERSIDADE ESTADUAL DO NORTE FLUMINENSE DARCY RIBEIRO (UENF)), Júlia Nunes Tardivo (UNIVERSIDADE ESTADUAL DO NORTE FLUMINENSE DARCY RIBEIRO (UENF) ), Camila Vasconcellos Fernandez (UNIVERSIDADE ESTADUAL DO NORTE FLUMINENSE DARCY RIBEIRO (UENF)), elaine cristina pereira (universidade estadual do norte fluminense darcy ribeiro (uenf))
Abstract:
In this work, the influence of the ionic liquid (3-indolymethyl) trimethylammonium iodide was evaluated as a corrosion inhibitor in the corrosive medium of hydrochloric acid for duplex stainless steel S31803 welded by the TIG process and thermally treated. The microstructure of the sample after welding and heat treatment was analyzed before the corrosive process, using the technique of confocal microscopy, in order to analyze the concentration of the phases. Then, the mechanical tensile test was performed. The corrosive process was performed using 1M hydrochloric acid solution and 1M hydrochloric acid solution containing 0.4mM of the proposed ionic liquid. The microstructure of duplex stainless steel S31803 is composed of two phases, ferrite and austenite, with an approximate balance of 50% by volume of the phase fractions present. The welding and heat treatment process was not able to cause negative damage to the mechanical properties of the material. The HCl corrosive medium without the corrosion inhibitor provided uniform corrosion development on the material. Deterioration of the passive film was observed, significantly increasing the corrosion rate. The corrosive medium containing the ionic liquid, developed uniform corrosion in the material, but its rate was 40x lower when compared to the sample without the inhibitor. In the end, it was concluded that (3-indolymethyl) trimethylammonium iodide presented an efficiency of 30.14% when used as a corrosion inhibitor.
