%0 Journal Article
%T Sweet Corrosion Inhibition on API 5L-B Pipeline Steel
%A Mahmoud Abbas Ibraheem
%A Abd El Aziz El Sayed Fouda
%A Mohamed Talaat Rashad
%A Fawzy Nagy Sabbahy
%J ISRN Metallurgy
%D 2012
%R 10.5402/2012/892385
%X Corrosion inhibition and adsorption behavior of two triazole derivatives on API 5L-B carbon steel in CO2-saturated 3.5% NaCl solutions was investigated using potentiodynamic polarization, EIS, and EFM techniques. Specimen surfaces were characterized using SEM, EDX, and XRD. Results show that the two compounds are mixed-type inhibitors and inhibition efficiency increases with increasing concentrations. Adsorption of the two compounds chemisorption and obeys Langmuir adsorption isotherm. Activation energy and thermodynamic parameters were calculated. Surface analyses confirm the formation of iron nitrides on the metal surface which supports results obtained from previous techniques. 1. Introduction Carbon dioxide which is present naturally in oil and gas wells is injected purposely into wells to enhance oil recovery. CO2 corrosion, also known as ¡°sweet corrosion,¡± is one of the major problems in oil and gas industry, costing billions of dollars every year. Great efforts must be expended in corrosion control for safety, business, and environmental considerations. Sweet corrosion is caused by the presence of carbon dioxide (CO2) dissolved in water to form carbonic acid (H2CO3). Corrosion increase as the concentration of CO2, system pressure, and temperature increase. This corrosion is typically slow, localized and results in pitting attack. Pits are very difficult to detect because of their tiny size and the corrosion products that cover them. In oil and gas production and processing industries, corrosion inhibitors have always been considered the first line of defense against internal corrosion. Inorganic inhibitors, such as sodium arsenite (Na2HAsO3) and sodium ferrocyanide, were used in early days to inhibit carbon dioxide (CO2) corrosion in oil wells, but the treatment frequency and effectiveness were not satisfactory. This led to the development of many organic chemical formulations that frequently incorporated film-forming amines and their salts. In this work, the corrosion inhibition and adsorption behavior of Itraconazole and Fluconazole compounds on API 5L-B carbon steel in CO2-saturated 3.5% NaCl solutions was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy, and electrochemical frequency modulation techniques. The surfaces of the samples were characterized using SEM, EDX, and XRD techniques. The effect of temperature on the corrosion rates and inhibition process was also investigated. 2. Experimental 2.1. Materials Preparation Experiments were conducted using a conventional three-electrode 200£¿mL cell
%U http://www.hindawi.com/journals/isrn.metallurgy/2012/892385/