CO_2 corrosion inhibition of X-70 pipeline steel by carboxyamido imidazoline

摘要

The corrosion inhibition of X-70 pipeline steel in saltwater saturated with CO_2 at 50 °C with carboxyamido imidazoline has been evaluated by using electrochemical techniques. Techniques included polarization curves, linear polarization resistance, electrochemical impedance, and electrochemical noise measurements. Inhibitor concentrations were 0, 1.6×10~(-5), 3.32×10~(-5), 8.1×10~(-5), 1.6×10 ~(-4), and 3.32×10~(-4) mol l~(-1). All techniques showed that the best corrosion inhibition was obtained by adding 8.1×10~(-5) mol l~(-1) of carboxyamido imidazoline. For inhibitor concentrations higher than 8.1×10~(-5) mol l ~(-1) a desorption process occurs, and an explanation has been given for this phenomenon.