Sweet Corrosion Inhibition on API 5L-B Pipeline Steel

Abstract

Corrosion inhibition and adsorption behavior of two triazole derivatives on API 5L-B carbon steel in CO 2 -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.

A Review of Recent Advances in the Inhibition of Sweet Corrosion

“…Various azole compounds, including imidazole, benzimidazole, 2‐mercaptobenzimidazole, and thiadiazoles derivatives, were tested as CIs for steel in a CO 2 environment [30e,33–34,42b‐d,49,57,68,79f,87,103,121a,132] . The corrosion inhibition effectiveness of these types of compounds was studied after 15 min–168 h of immersion in either CO 2 ‐saturated NaCl solutions [30e,42c,68,79f,103,121a,132] or CO 2 ‐saturated brine/oilfield produced water [34,42b,d,57,87] within a temperature range from room temperature to 80 °C.…”

Adsorption and Corrosion Inhibition Potentials of Salicylaldehyde-based Schiff Bases of Semicarbazide and p-Toluidine on Mild Steel in Acidic Medium: Experimental and Computational Studies

“…These include the surface charge of the metal in an electrolyte, which invariably depends on the potential of zero charge (PZC), the type of heteroatoms or lone-pair electrons in the inhibitor molecule, and the proton affinity of the inhibitor molecule [50]. Two major modes of adsorption have been widely proposed for inhibition of steel corrosion in acid by organic compounds [51]. Neutral molecules of the inhibitor may be adsorbed on the steel surface via sharing of lone-pair electrons on the heteroatoms with the vacant d-orbitals of Fe, or donor-acceptor interactions between the pi-electrons of inhibitor molecules and d-orbitals of Fe, leading to chemical adsorption.…”

A Review of CO2Corrosion Inhibition by Imidazoline-based Inhibitor

“…Steel surface is positively charged in acid solution. As chloride ions have small degree of hydration, they could bring excess negative charges in the vicinity of the metal-solution interface, promoting more adsorption of the positively charged inhibitor molecules through electrostatic interactions [4]. On the other hand, Nesic et.…”

“…The film-type corrosion inhibitors are mainly inorganic, such as chromate and nitrate. The disadvantages of inorganic inhibitors are that they are required in large dosages, apart from their poor feasibility, high treatment frequency and unsatisfactory effectiveness [4,5]. The adsorption-type inhibitors reduce corrosion rate by forming layers of hydrophobic film on metal surface, which hinders transfer of substance and charges related to corrosion reactions.…”

“…Therefore the most economical solution is to control the rate of the corrosion. Corrosion inhibitors have been considered as the first line defense against internal corrosion of pipelines [4]. In conjunction with the use of carbon steel, corrosion inhibitors have been recognized as the most practical and cost-effective option.…”