Título del libro: European Corrosion Congress 2009, Eurocorr 2009
Título del capítulo: Corrosion behavior of API 5L X-52 line pipe steel in CO2 (aq) and cr (aq) solutions in presence of aminotriazole based inhibitor under hydrodynamic conditions
JUAN GENESCA LLONGUERAS;
Autores externos:
Idioma:
Año de publicación:
2009
Resumen:
The use of film forming inhibitors has been a widely used practice in the control of corrosion in hydrocarbon transport pipelines. The performance of these types of inhibitors depends on their ability to form a continuous film upon the surface of the metal that will be protected against corrosion, isolating it from the aggressive environment. In most cases, the corrosion environment is in constant movement. This is a common situation in the transport of hydrocarbons in steel pipelines. In industrial processes fluid flow in pipes is usually turbulent. In order to obtain information about the performance of film forming inhibitors, laboratory tests are carried out. The most common type of laboratory tests are based on weight loss of metallic coupons, which have been exposed to a test environment for a certain period of time. Some other tests use electrochemical measurements as linear polarization resistance (LPR) to measure and monitor the rate of general corrosion. At the same time, it is known that, with a limited success, the electrochemical techniques can be used for measuring the corrosion rate controlled by the diffusion of species in the flowing solution, i.e. flow-dependent corrosion rate. Some methodologies have been developed in order to asses the performance of film forming inhibitors in moving environments. These methodologies use hydrodynamic test systems such as, rotating cylinders, impingement jets or pipe-loops. The primary purpose of this work was to study the effect that turbulent flow has on the electrochemical behaviour of a 3-amino- 1,2,4- triazole (aminotriazole or 3-AT) based corrosion inhibitor by using a rotating cylinder electrode, RCE. The experiments were carried out in a typical three-electrode electrochemical cell arrangement. The RCE was made of an API X52 pipeline steel and acted as working electrode. The test environment used in all experiments was a 3% NaCl solution saturated with CO2 at 20 °C. Linear polarization resistance, LPR and polarization curves were used to determine the electrochemical behaviour of the steel in the environment, at different rotation rates (100, 1000, 3000 and 5000 rpm) and inhibitor concentrations (0, 25 y 100 ppm). It was found that the aminotriazole inhibitor studied follows, under the experimental conditions of this study, the typical behavior of a Langmuir isotherm. The inhibiting effect increased as a function of flow reaching a maximum efficiency of 74.62 % for an inhibitor concentration of 100 ppm at 5000 rpm.
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ISBN:
9781615677962
Editorial:
Tipo de producto:
Conference Paper
