Investigation of inhibitor effectiveness depending on environment parameters at the inhibition of 1010 steel

The corrosion of boilers and pipelines can be prevented with using inhibitors. In this study, the aim was the prevention of corrosion of 1010 steel. Some aminoacids were used for corrosion inhibition of 1010 steel in wt %0,5 HCl solution and efficiencies were determined between 20ºC-60ºC. The effect of L-arginyn, L-methyonine, L-aspargine monohydrate, L-histidyne, L-leucine, D-valine, D-alanine, D-phenyl alanine, glycine, D-L-aspartic acid, L-cystine, L-cysteine hydrochloride monohydrate, N-acetyle-L-cysteine were investigated. The inhibition efficiencies were calculated with the use of Tafel extrapolation method and Linear polarization method.Inhibitor efficiency at 20ºC was found to be 82,5% for 1000 ppm N-acetyle-L-cysteine, 78% for 1000 ppm L-methyonine, 72% for 5000 ppm D-L-aspartic acid, 72% for 5000 ppm L-aspargine monohiyrate and 55,5% for L-cystine. When the experiments were made at higher temperatures, it seemed that inhibitor efficiency decreased with increasing temperature. Inhibitors which include sulphur and nitrogen atoms were most effective.The aminoacids affect with adsorption at the metal surface. Adsorption were in accordance with the Langmuir and Freundlich isoterms. Activation energies were calculated from Ln I-1/T graph at constant inhibitor consantration. The results were as follows; Ea = 25733 j/mol for 1000 ppm N-acetyle-L-cysteine, Ea = 28400 j/mol for 1000 ppm L-methyonine, Ea = 23847 j/mol for 5000 ppm D-L-aspartic acid, Ea = 29782 j/mol for 5000 ppm L-aspargine monohiydrate, Ea = 15875 j/mol for 5000 ppm L-cystine, Ea = 7770 j/mol fort he corrosion without inhibitor. The activation energy of the solution without inhibitor were lower than the activation energies of solutions with inhibitor. This result indicates that inhibitor enables protection against corrosion of 1010 steel.N-acetyle-L-cysteine and L-methyonine were studied in H2SO4 solution. The efficiency of N-acetyle-L-cysteine was 65% and the efficiency of L-methyonine was 71%.