Efficient Corrosion Inhibition of API 5L X52 STEEL in HCl By NN-Functionalized 1,2,3-Triazoles

The corrosion inhibition efficiency (IE) of a series of NN-functionalized 1,2,3-Triazoles was measured in the system: pipeline steel grade API 5L X52 / 1M HCl, using electrochemical impedance spectroscopy (EIS). The influence of the inhibitor concentration on the IE of all these compounds was determined. The results showed that in all cases the IE increased with increasing inhibitor concentration, and the best inhibitor of the series resulted the p-fluorinatedbenzyl triazole (TDF) with 96% of EI at 15 ppm.

Overall, it was found that the inhibitors follow a physisorption mechanism, which can be adequately described by the Langmuir isotherm. Moreover, it is shown that these compounds can affect both the anodic and cathodic processes, thus it can be classified as a mixed-type inhibitor that may block both anodic and cathodic sites in the API 5L X52 steel surface immersed in HCl.